CN115774903A - Helicopter rotor disc load real-time generation method, device, equipment and medium - Google Patents
Helicopter rotor disc load real-time generation method, device, equipment and medium Download PDFInfo
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Abstract
The application relates to the field of computational fluid mechanics, and discloses a method, a device, equipment and a medium for generating a load of a rotor disc of a helicopter in real time, wherein the method comprises the following steps: firstly, generating section airfoil discrete points of each blade at different spanwise positions; calculating and storing an interpolation relation between the object plane grid of each blade and the section airfoil discrete points; then, according to the stored interpolation relation, acquiring pressure coefficients on the section airfoil discrete points of the different spanwise positions of each blade in real time by utilizing unsteady CFD simulation; and finally, according to the obtained pressure coefficient, integrating to obtain the distribution of the section force so as to generate a paddle load result in real time. Therefore, the corresponding section force distribution information of each blade can be obtained at the same time, the blade disc load is generated in real time, flow field files of all physical moments in the whole calculation process do not need to be stored, the data processing efficiency is high, and the requirement on hardware storage space is low.
Description
Technical Field
The invention relates to the field of computational fluid mechanics, in particular to a method, a device, equipment and a medium for generating a load of a rotor disc of a helicopter in real time.
Background
Helicopters are widely used in various fields of the national civilization. The rotor is the main power component of the helicopter, and provides upward pulling force and forward pushing force for the helicopter. In different phases, the rotor blades have different postures, the relative positions of the blades and incoming flows are different, and the load distribution on the blades is different. The so-called rotor disc load can be obtained by rotating the rotor for one circle and calculating, collecting and collating the load distribution of the blades on different phases. The rotor disc load distribution can be used for evaluating the aerodynamic performance of the helicopter and used as the input of optimizing the rotor wing design, and has great significance for improving the performance of the helicopter.
In the field of helicopter Computational Fluid Dynamics (CFD), it is generally necessary to store the spatial flow field at different times of rotor rotation, each time the rotor is in a particular phase, when calculating the rotor disc load. And then, respectively processing the space flow field at each moment to obtain the blade load distribution of the corresponding phase, thereby generating the blade disc load.
The defects of the method for generating the paddle load are as follows: flow field files at different moments in a period need to be stored, and the requirement on hardware storage space is high; the paddle load can only be generated after calculation is finished, and the change of the paddle load cannot be monitored in real time; if a complete change process of the rotor blade disc load in the CFD calculation process is obtained, flow fields at all physical moments in the whole CFD calculation process are required to be stored instead of the flow field at the physical moment included in the last rotation period, and the storage requirement and the processing time of a hard disk are further increased; rotors typically have multiple blades and this approach does not allow multiple phases of cross-sectional force distribution to be achieved at one time.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a method, an apparatus, a device, and a medium for generating a rotor disc load of a helicopter in real time, which can generate a rotor disc load result in real time, without storing flow field files at all physical moments in the whole calculation process, and have high data processing efficiency and low requirements for hardware storage space. The specific scheme is as follows:
a real-time generation method for a helicopter rotor disc load comprises the following steps:
generating section airfoil discrete points of each blade at different spanwise positions;
calculating and storing an interpolation relation between the object plane grid of each blade and the section airfoil discrete points;
according to the stored interpolation relation, acquiring pressure coefficients on the section airfoil discrete points of the blades at different spanwise positions in real time by utilizing unsteady CFD simulation;
and according to the obtained pressure coefficient, integrating to obtain the section force distribution so as to generate a paddle load result in real time.
Preferably, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, generating discrete points of a section airfoil of each blade at different spanwise positions includes:
selecting a blade, setting the object plane of the selected blade at a 0-phase position, and setting three aerodynamic force direction unit vectors corresponding to the selected blade;
selecting a plurality of stations along the spanwise direction of the 0-phase blade, cutting the blade to obtain a section airfoil profile based on a plane vertical to the spanwise direction in each station, and dispersing the section airfoil profile into discrete points;
and (4) sequentially rotating the object surfaces of the other selected blades to 0 phase position around the rotating shaft of the rotor wing to obtain corresponding section airfoil discrete points.
Preferably, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, the obtaining pressure coefficients at discrete points of the cross-sectional profile of each blade at different spanwise positions in real time by using a non-steady CFD simulation according to the stored interpolation relationship includes:
setting a physical time step of one rotation of the rotor wing; the number of the physical time steps is integral multiple of the total number of the blades;
rotating the blade skin grid to a corresponding phase in the process of performing unsteady CFD simulation of the current physical time step, and exchanging flow field variables of the blade skin grid and a background grid by an overlapping grid method;
and simultaneously, interpolating the static pressure on the blade body grid to the section airfoil profile discrete points according to the stored interpolation relation, and acquiring the pressure coefficients of the section airfoil profile discrete points at different spanwise positions of each blade on the current physical time step.
Preferably, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, the interpolating the static pressure on the blade skin mesh to the section airfoil profile discrete point according to the stored interpolation relationship, and obtaining the pressure coefficient at the section airfoil discrete point at the different spanwise position of each blade at the current physical time step includes:
for each wall surface grid point of each blade, determining a space grid unit containing the wall surface grid point;
carrying out arithmetic mean on the determined static pressure on the space grid unit, assigning the static pressure to the wall surface grid point, and calculating a pressure coefficient on the wall surface grid point of each blade on the current physical time step;
and acquiring the pressure coefficient of the section airfoil discrete point of each blade at different spanwise positions on the current physical time step according to the calculated pressure coefficient of the wall surface grid point of each blade and the stored interpolation relation.
Preferably, in the method for generating a rotor disc load of a helicopter rotor provided in the embodiment of the present invention in real time, a first formula is used to calculate a pressure coefficient at a grid point of a wall surface of each blade at a current physical time step; the first formula is:
wherein ,Pis the static pressure at the grid point or points,
for the purpose of reference to the pressure,
for reference to the speed of sound,C p in order to be the pressure coefficient,Mis the incoming flow mach number.
Preferably, in the above method for generating a load of a rotor disk of a helicopter in real time according to an embodiment of the present invention, the obtaining of the cross-sectional force distribution by integrating according to the obtained pressure coefficient includes:
dividing the section airfoil into small line segments with the same number as the total number of the section airfoil discrete points;
calculating a representative vector of each small line segment;
calculating a pressure coefficient and a coordinate at the center of each small line segment;
calculating a surface vector formed by extending the small line segments along the extending direction by unit length according to the representation vector of each small line segment;
and obtaining the section force and moment corresponding to the section wing profile according to the calculated surface vector, the pressure times and coordinates at the center, the set reference coordinate, the set reference area, the set reference length and the total number of the discrete points.
Preferably, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, after obtaining a section force and a moment corresponding to a section airfoil, the method further includes:
according to the obtained section force and moment and the set unit vectors of the three aerodynamic directions, obtaining the section force coefficient distribution of each blade at each span-wise position;
storing the distribution of the section force coefficient of each blade on the phase corresponding to the current physical time step of each blade;
and outputting the blade section force coefficient distribution of all phases as a blade disc load result.
The embodiment of the invention also provides a device for generating the load of the rotor disc of the helicopter in real time, which comprises:
the discrete point generating module is used for generating section airfoil discrete points of each blade at different spanwise positions;
the interpolation relation calculation module is used for calculating and storing the interpolation relation between the object plane grid of each blade and the section airfoil discrete points;
the pressure coefficient acquisition module is used for acquiring pressure coefficients on the section airfoil discrete points of the blades at different spanwise positions in real time by utilizing unsteady CFD simulation according to the stored interpolation relation;
and the paddle load generation module is used for obtaining the section force distribution through integration according to the acquired pressure coefficient so as to generate a paddle load result.
The embodiment of the present invention further provides a real-time helicopter rotor disc load generation device, which includes a processor and a memory, wherein the processor implements the real-time helicopter rotor disc load generation method provided by the embodiment of the present invention when executing a computer program stored in the memory.
Embodiments of the present invention further provide a computer-readable storage medium for storing a computer program, where the computer program, when executed by a processor, implements the above method for generating a load of a rotor disk of a helicopter in real time, according to an embodiment of the present invention.
According to the technical scheme, the real-time generation method of the helicopter rotor disc load provided by the invention comprises the following steps: generating section airfoil discrete points of each blade at different spanwise positions; calculating and storing an interpolation relation between the object plane grid of each blade and the section airfoil discrete points; according to the stored interpolation relation, acquiring pressure coefficients on the section airfoil discrete points of each blade at different spanwise positions in real time by utilizing unsteady CFD simulation; and according to the obtained pressure coefficient, integrating to obtain the section force distribution so as to generate a paddle load result in real time.
The invention provides a real-time generation method of the helicopter rotor disc load, which comprises the steps of firstly generating discrete points of a blade section before unsteady CFD simulation, and calculating and storing the interpolation relation between the discrete points and a blade object plane grid; and then in the unsteady calculation process, the stored interpolation relation is utilized to obtain the pressure coefficient on the airfoil discrete point of the section of each blade at different spanwise positions in real time when the blade moves, and the section force distribution is obtained through integration, so that the load result of the propeller disk is generated in real time, the whole process is automatic, the section force distribution information corresponding to each blade can be obtained at the same time, flow field files of all physical moments in the whole calculation process do not need to be stored, the data processing efficiency is high, and the requirement on hardware storage space is low.
In addition, the invention also provides a corresponding device, equipment and a computer readable storage medium for the helicopter rotor disc load real-time generation method, so that the method has higher practicability, and the device, the equipment and the computer readable storage medium have corresponding advantages.
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In order to more clearly illustrate the embodiments of the present invention or technical solutions in related arts, the drawings used in the description of the embodiments or related arts will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a flowchart of a method for generating a rotor disc load of a helicopter in real time according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a helicopter rotor computational grid provided by an embodiment of the present invention;
FIG. 3 is a schematic view of a rotor object plane grid provided by an embodiment of the present invention;
FIG. 4 is a schematic diagram of a unit vector of aerodynamic force provided by an embodiment of the present invention;
FIG. 5 is a schematic view of discrete points of a cross-sectional airfoil at different spanwise locations for a rotor blade according to an embodiment of the present invention;
FIG. 6 is a schematic illustration of a discrete point numbering for a airfoil with a cross-section according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of a calculation of object plane grid point pressure coefficients for a rotor blade according to an embodiment of the present invention;
fig. 8a to 8f are schematic diagrams illustrating the results of the loading of the paddle disk at different physical time steps according to the embodiment of the present invention;
fig. 9 is a schematic structural diagram of a device for generating a rotor disc load of a helicopter in real time according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a real-time generation method of a helicopter rotor disc load, which comprises the following steps as shown in figure 1:
s101, generating section airfoil discrete points of each blade at different spanwise positions;
before executing step S101, the method may further include: and generating a helicopter rotor calculation grid. As shown in fig. 2, a respective skin mesh is generated for each blade, the skin mesh falling inside the background mesh. If the helicopter body is considered in the calculation process, the background grid is a body grid; if the fuselage is not considered, there is no object plane in the background grid. In step S102, for a blade, cross-section airfoil discrete points at different spanwise positions of the current phase are generated and output, and then other blades are rotated around the rotor rotation shaft to the current phase of the blade, so as to generate a corresponding cross-section airfoil discrete point.
S102, calculating and storing an interpolation relation between an object plane grid and a section airfoil discrete point of each blade;
it should be noted that, the mutual connection relationship of the object plane grid points and the serial numbers of the object plane grid points are not changed when the object plane grid points of each blade are rotated, so that the interpolation relationship calculated based on the rotated object plane points is also applicable to the object plane grid points before rotation. The interpolation relation stored in step S102 is not changed in the subsequent calculation process.
S103, acquiring pressure coefficients on the airfoil discrete points of the section of each blade at different spanwise positions in real time by utilizing unsteady CFD simulation according to the stored interpolation relation;
in step S103, during the unsteady calculation process, the blades generate flapping/shimmy/torsion and deformation motions, and the pressure coefficients at the discrete points of the section airfoil at different spanwise positions of each blade can be obtained in real time through the interpolation relationship stored in step S102.
And S104, integrating according to the obtained pressure coefficient to obtain the section force distribution so as to generate a paddle load result in real time.
It should be noted that, when the blade rotates 1/N (N is the number of blades), the disk load of the whole rotation plane can be obtained, and then the disk load is continuously refreshed with the phase in the calculation, and finally converges to a stable value.
In the real-time helicopter rotor disc load generation method provided by the embodiment of the invention, firstly, before unsteady CFD simulation, blade section discrete points are generated, and an interpolation relation between the blade section discrete points and a blade object plane grid is calculated and stored; and then in the unsteady calculation process, the stored interpolation relation is utilized to obtain the pressure coefficient on the airfoil discrete point of the section of each blade at different spanwise positions in real time when the blade moves, and the section force distribution is obtained through integration, so that the load result of the propeller disk is generated in real time, the whole process is automatic, the section force distribution information corresponding to each blade can be obtained at the same time, flow field files of all physical moments in the whole calculation process do not need to be stored, the data processing efficiency is high, and the requirement on hardware storage space is low.
Further, in practical implementation, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, the step S101 may generate discrete points of a cross-sectional airfoil profile of each blade at different spanwise positions, and specifically include: firstly, selecting a blade, setting the object plane of the selected blade at a 0-phase position, and setting three aerodynamic force direction unit vectors corresponding to the selected blade; selecting a plurality of stations along the spanwise direction of the 0-phase blade, cutting the blade to obtain a section airfoil profile based on a plane vertical to the spanwise direction in each station, and dispersing the section airfoil profile into discrete points; and then, sequentially rotating the object planes of the other blades except the selected blade to 0 phase position around the rotating shaft of the rotor wing to obtain corresponding section airfoil discrete points.
Fig. 3 shows a schematic view of a rotor blade object plane grid, in this example the number of blades of the rotor is 4, so there are 4 blade object planes. Selecting one blade from 4 blades, setting the phase of the blade as 0 phase and setting unit vectors of three force directions corresponding to the blade as shown in fig. 4; wherein the unit vector
Are orthogonal to each other. Next, in the 0-phase blade spanwise direction: (
Direction) can select a plurality of station positions, and the number of the station positions is Nr. As shown in fig. 5, at each station, the base is perpendicular to
The blade can be cut to obtain a section airfoil A, and the section airfoil A is discretized into discrete points. Meanwhile, setting reference coordinates for calculating aerodynamic coefficients at different station positions
Reference lengthL ref,i And reference areaS ref,i , wherein i=1,2,…, Nr。
Subsequently, each section airfoil discrete point can be processedAnd (6) numbering. As shown in FIG. 6, taking a section airfoil as an example, the number direction of the discrete points is determined according to the right hand rule, and
the direction is opposite. It should be noted that the number of discrete points may vary from section to section airfoil, but the density of discrete points per section airfoil needs to be sufficient to represent aerodynamic changes on the blade.
In practical application, the number of the blades can be set asN blade The number of the 0-phase blade is 1, and the other blades are numbered 2, \ 8230in order along the rotation direction of the rotor,N blade 。
and reading in discrete points of the section airfoil profile through a No. 0 process. And aiming at the object plane grid point of each blade, firstly, the No. 0 process is collected, and then the rotor rotates around the rotating shaft of the rotor to return to the phase 0. In the process No. 0, the interpolation relation of interpolation from the object plane grid to the discrete points is calculated aiming at the discrete points of the object plane grid and the section airfoil of each blade in the phase 0, namely: and aiming at a certain discrete point, related object plane grid points and weight coefficients when physical quantities on the object plane grid points interpolate to the discrete point.
In specific implementation, in the method for generating a rotor disc load of a helicopter rotor in real time according to the embodiment of the present invention, step S103 may include the following steps of, according to a stored interpolation relationship, obtaining a pressure coefficient at a discrete point of an airfoil profile of a section of each blade at a different spanwise position in real time by using an unsteady CFD simulation:
firstly, setting a physical time step of one rotation of a rotor wing; the number of the physical time steps is integral multiple of the total number of the blades. Specifically, the physical time step number of one rotation of the rotor wing is set to be a positive integer Nphase, and the Nphase is required to beN blade Integer multiples of. The time of one rotation of the rotor is divided by Nphase to be the time step of the unsteady calculation. It will be appreciated that in the CFD calculation, nphase phases are calculated for one rotor revolution. When the paddle load is counted, an array bladeface (Nphase, nr, 6) can be opened up for the spanwise cross-sectional force distribution of the Nphase phases, and the Nphase phases are storedNr cross-sectional positions. The six-component force is a force coefficient in three directions and a moment coefficient in three directions.
And then, in the process of carrying out unsteady CFD simulation of the current physical time step, rotating the blade skin grid to a corresponding phase, and exchanging flow field variables of the blade skin grid and the background grid by an overlapping grid method. Specifically, at each physical time step of the unsteady computation, the rotor fit grid can be rotated to the corresponding phase; at the phase, the close-fit grid is transferred to a corresponding position in a rigid motion mode according to the motion rules of blade flapping, torque conversion and the like; and exchanging flow field variables of the rotor blade skin grid and the background grid through an overlay grid technology during CFD calculation.
And simultaneously, interpolating the static pressure on the blade body-attached grid to the section airfoil discrete point according to the stored interpolation relation, and acquiring the pressure coefficient of each blade on the section airfoil discrete point at different spanwise positions on the current physical time step.
In specific implementation, as shown in fig. 7, for each wall surface grid point of each blade, it is necessary to determine which spatial grid cells adjacent to the wall surface grid point are, that is, which spatial grid cells have grid points including the wall surface grid point; carrying out arithmetic mean on the determined static pressures on the space grid units, assigning the static pressures to the wall surface grid points, and calculating the pressure coefficient of each blade wall surface grid point on the current physical time step; and sends the acquired pressure coefficient at the grid point of the wall surface of each blade to the process No. 0. And then, acquiring pressure coefficients of the section airfoil discrete points of each blade at different spanwise positions on the current physical time step according to the calculated pressure coefficients of the wall surface grid points of each blade and the stored interpolation relation.
In specific implementation, a first formula can be adopted to calculate the pressure coefficient of each blade wall surface grid point on the current physical time step; the first formula is:
wherein ,PIs the static pressure at the grid point,
for the purpose of the reference pressure, the pressure is,
in order to refer to the speed of sound,C p in order to be the pressure coefficient,Mis the incoming flow mach number.
In a specific implementation, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, the step S104 may obtain a cross-sectional force distribution by integrating according to the obtained pressure coefficient, and specifically include:
taking a certain section airfoil as an example, as shown in fig. 6, the total number of discrete points is N. Knowing the coordinates of these N discrete points as
The pressure coefficient at a discrete point is
. Without loss of generality, if the cross section is the jth cross section, the corresponding reference coordinate, reference length and reference area are respectively
。
Firstly, dividing a section airfoil into small line segments with the same number as the total number of discrete points of the section airfoil; i.e. the section airfoil is divided into N small line segments.
Then, a representative vector of each small line segment is calculated
：
Then, the pressure coefficient at the center of each small line segment is calculatedf i And coordinates
：
Then according to the expression vector of each small line segment
Number of pressure at centerf i And coordinates
Set reference coordinates
Reference areaS ref,j And a reference lengthL ref,j And the total number N of the discrete points to obtain the section force corresponding to the section airfoil
Sum moment
：
Since the airfoil discrete point is located on the blade with the phase 0, the pressure coefficients of all the blades are calculated based on the airfoil discrete point, and therefore the uniformity of calculation of aerodynamic coefficients of different phases is guaranteed.
Further, in a specific implementation, in the method for generating a rotor disc load of a helicopter in real time according to the embodiment of the present invention, after obtaining a section force and a moment corresponding to a section airfoil, the method may further include:
first, based on the obtained section force
Sum moment
And three aerodynamic force direction unit vectors are arranged, and the section force coefficient distribution (namely, six-component force coefficient) of each blade at each spanwise position is obtained:
then, storing the distribution of the section force coefficient on each blade on the phase corresponding to the current physical time step of each blade; namely: and storing the section force load distribution of different blades on different phases at the current physical time step.
The phase number of the k blade at the initial 0 moment is:
without loss of generality, assume a current physical time step ofN step Then, the phase corresponding to the i-th blade section force is:
the six-component force coefficients obtained from equations (8) through (13) may be stored in the array bladefore as follows:
in this way it is possible to obtain,N blade and the blade blades refresh the values of four phases of the blade disc load at the same time.
And finally, outputting the blade section force coefficient distribution of all phases as a blade disc load result.
Specifically, the paddle load is output in a two-dimensional graph. Wherein, under polar coordinate system, the radial position and the circumferential angle of phase, jth station are respectively:
the coordinates in a two-dimensional cartesian coordinate system are:
and mapping the data of the array bladeForce to the coordinates shown in the formulas (22) to (25) to obtain the real-time paddle load at the current moment.
The method for generating the rotor disc load of the helicopter in real time provided by the embodiment of the invention is described below by taking calculation of the rotor disc load of a certain helicopter as an example, and the method comprises the following specific steps:
step one, generating a computational grid of rotors shown in fig. 2.
And step two, selecting a certain blade, and setting the object plane of the certain blade to be at the 0 phase position. As shown in fig. 4, unit vectors of three directions of the calculated aerodynamic force are set for the blade.
Step three, along the 0-phase blade spanwise direction (
Direction) selects a plurality of station positions, and the number of the station positions is Nr. As shown in fig. 5, at each station, the base is perpendicular to
And cutting the blade to obtain a section airfoil profile, and dispersing the section airfoil profile into discrete points.
And fourthly, numbering the discrete points of the airfoil profile of each section. As shown in FIG. 6, taking a certain section airfoil as an example, the number direction of the discrete points thereof, and
the direction is opposite.
And step five, rotating the object plane of each blade to the 0 phase position, and transmitting to the 0 process. And then calculating the interpolation relation of each blade to the discrete points of the airfoil profile, and storing the interpolation relation in the 0 process. This interpolation relationship does not change in the present simulation.
And step six, setting the rotation of the rotor blades for one circle, and calculating 120 physical time steps. The unsteady CFD simulation is started and data is exchanged between the rotor blade grid and the background grid via an overlay grid technique.
And seventhly, after the simulation of one physical time step is completed, interpolating the static pressure on the blade body-fitted grid to the section airfoil discrete point, and calculating the pressure coefficient on the section airfoil discrete point.
And step eight, calculating six-component force coefficients of each blade on each span-wise station based on the pressure coefficients on the discrete points of the section airfoil, namely the distribution of the section force coefficients on the blade.
And step nine, distributing the section force coefficients of each blade, and storing the section force coefficients in the corresponding phase of the blade at the current moment.
Step ten, outputting the blade section force coefficient distribution of all phases, namely the blade disc load. FIG. 8a shows the paddle loading results for physical time step 9 (
). FIG. 8b shows the results of the paddle loading for a physical time step of 19 (
). FIG. 8c shows the paddle loading results for physical time step 29 (C)
). FIG. 8d shows the paddle loading results for physical time step 39: (
). FIG. 8e shows the paddle loading results for physical time step 49 (C:)
). FIG. 8f shows the paddle loading results for a physical time step of 59: (
). From fig. 8c it can be seen that when the blade is turned 1/4 of a turn, the disc load of the entire rotation plane is obtained. From FIG. 8f, it can be seen thatThe paddle loading converges to a steady value.
Based on the same inventive concept, the embodiment of the invention also provides a device for generating the rotor disc load of the helicopter in real time, and as the problem solving principle of the device is similar to that of the method for generating the rotor disc load of the helicopter in real time, the implementation of the device can refer to the implementation of the method for generating the rotor disc load of the helicopter in real time, and repeated parts are not repeated.
In specific implementation, the device for generating a load of a rotor disk of a helicopter according to an embodiment of the present invention, as shown in fig. 9, specifically includes:
the discrete point generating module 11 is used for generating section airfoil discrete points of each blade at different spanwise positions;
the interpolation relation calculation module 12 is used for calculating and storing an interpolation relation between the object plane grid of each blade and the section airfoil discrete points;
the pressure coefficient acquisition module 13 is configured to acquire pressure coefficients at different spanwise position section airfoil discrete points of each blade in real time by using unsteady CFD simulation according to the stored interpolation relationship;
and the paddle load generation module 14 is used for integrating the acquired pressure coefficient to obtain a section force distribution so as to generate a paddle load result.
In the device for generating the helicopter rotor disc load in real time provided by the embodiment of the invention, the cross-sectional force distribution information corresponding to each blade can be acquired at the same time through the interaction of the four modules, the disc load result can be generated in real time, flow field files of all physical times in the whole calculation process are not required to be stored, the data processing efficiency is high, and the requirement on hardware storage space is low.
For more specific working processes of the above modules, reference may be made to corresponding contents disclosed in the foregoing embodiments, and details are not described herein again.
Correspondingly, the embodiment of the invention also discloses equipment for generating the load of the rotor disc of the helicopter in real time, which comprises a processor and a memory; wherein the processor, when executing the computer program stored in the memory, implements the helicopter rotor disc load real-time generation method disclosed in the foregoing embodiments. For more specific processes of the method, reference may be made to corresponding contents disclosed in the foregoing embodiments, and details are not repeated here.
Further, the present invention also discloses a computer readable storage medium for storing a computer program; the computer program, when executed by a processor, implements the helicopter rotor disc load real-time generation method disclosed above. For more specific processes of the above method, reference may be made to corresponding contents disclosed in the foregoing embodiments, and details are not repeated here.
The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other. The device, the equipment and the storage medium disclosed by the embodiment correspond to the method disclosed by the embodiment, so that the description is relatively simple, and the relevant points can be referred to the method part for description.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in Random Access Memory (RAM), memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
To sum up, the method for generating the load of the rotor disc of the helicopter in real time provided by the embodiment of the invention comprises the following steps: generating section airfoil discrete points of each blade at different spanwise positions; calculating and storing an interpolation relation between the object plane grid of each blade and the discrete points of the section airfoil profile; according to the stored interpolation relation, acquiring pressure coefficients on the section airfoil discrete points of the blades at different spanwise positions in real time by utilizing unsteady CFD simulation; and according to the obtained pressure coefficient, integrating to obtain the section force distribution so as to generate a paddle load result in real time. According to the real-time generation method for the load of the rotor disc of the helicopter, the corresponding section force distribution information of each blade can be obtained at the same time, flow field files of all physical moments in the whole calculation process do not need to be stored, the data processing efficiency is high, and the requirement on hardware storage space is low. In addition, the invention also provides a corresponding device, equipment and a computer readable storage medium for the helicopter rotor disc load real-time generation method, so that the method has higher practicability, and the device, the equipment and the computer readable storage medium have corresponding advantages.
Finally, it should also be noted that, in this document, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
The method, the device, the equipment and the medium for generating the helicopter rotor disc load in real time provided by the invention are described in detail, a specific example is applied in the method for explaining the principle and the implementation mode of the invention, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.
Claims (10)
1. A real-time helicopter rotor disc load generation method is characterized by comprising the following steps:
generating section airfoil discrete points of each blade at different spanwise positions;
calculating and storing an interpolation relation between the object plane grid of each blade and the discrete points of the section airfoil profile;
according to the stored interpolation relation, acquiring pressure coefficients on the section airfoil discrete points of the blades at different spanwise positions in real time by utilizing unsteady CFD simulation;
and according to the obtained pressure coefficient, integrating to obtain the section force distribution so as to generate a paddle load result in real time.
2. A helicopter rotor disc load real-time generation method according to claim 1, wherein generating discrete points of a cross-sectional airfoil profile for each blade at different spanwise locations comprises:
selecting a blade, setting the object plane of the selected blade at a 0-phase position, and setting three aerodynamic force direction unit vectors corresponding to the selected blade;
selecting a plurality of stations along the spanwise direction of the 0-phase blade, cutting the blade to obtain a section airfoil profile based on a plane vertical to the spanwise direction in each station, and dispersing the section airfoil profile into discrete points;
and (4) sequentially rotating the object surfaces of the other selected blades to 0 phase position around the rotating shaft of the rotor wing to obtain corresponding section airfoil discrete points.
3. A helicopter rotor disc load real-time generation method according to claim 2, wherein obtaining pressure coefficients at discrete points of a cross-sectional airfoil profile at different spanwise locations for each blade in real-time using non-stationary CFD simulation based on said stored interpolation relationships comprises:
setting a physical time step of one rotation of the rotor wing; the number of the physical time steps is integral multiple of the total number of the blades;
in the process of performing unsteady CFD simulation of the current physical time step, rotating the blade skin grid to a corresponding phase, and exchanging flow field variables of the blade skin grid and a background grid by a grid overlapping method;
and simultaneously, interpolating the static pressure on the blade body grid to the section airfoil discrete points according to the stored interpolation relation, and acquiring the pressure coefficients of the section airfoil discrete points of each blade at different spanwise positions on the current physical time step.
4. A method for real-time generation of rotor disc loads of helicopter rotors according to claim 3, wherein the step of interpolating the static pressure on the blade-fitted grid to discrete points of the cross-sectional airfoil profile according to said stored interpolation relationship to obtain the pressure coefficients at the discrete points of the cross-sectional airfoil profile at different spanwise positions of each blade at the current physical time step comprises:
for each wall surface grid point of each blade, determining a space grid unit containing the wall surface grid point;
carrying out arithmetic averaging on the determined static pressure on the space grid unit, assigning to the wall surface grid point, and calculating a pressure coefficient on the wall surface grid point of each blade at the current physical time step;
and acquiring the pressure coefficient of the section airfoil discrete point of each blade at different spanwise positions on the current physical time step according to the calculated pressure coefficient of the wall surface grid point of each blade and the stored interpolation relation.
5. A helicopter rotor disc load real-time generation method according to claim 4, wherein a first formula is used to calculate the pressure coefficient at each blade wall surface grid point at the current physical time step; the first formula is:
wherein ,Pis the static pressure at the grid point or points,
for the purpose of reference to the pressure,
in order to refer to the speed of sound,C p in order to be the pressure coefficient,Mthe incoming flow mach number.
6. A helicopter rotor disc load real-time generation method according to claim 5, wherein integrating from said derived pressure coefficients yields a cross-sectional force profile comprising:
dividing the section airfoil into small line segments with the same number as the total number of the section airfoil discrete points;
calculating a representative vector of each small line segment;
calculating a pressure coefficient and a coordinate at the center of each small line segment;
calculating a surface vector formed by extending the small line segments along the extending direction by unit length according to the representation vector of each small line segment;
and obtaining the section force and moment corresponding to the section wing according to the calculated surface vector, the pressure times and coordinates at the center, the set reference coordinates, the set reference area, the set reference length and the total number of the discrete points.
7. A helicopter rotor disc load real-time generation method according to claim 6, further comprising, after obtaining section forces and moments corresponding to a section airfoil:
according to the obtained section force and moment and the set unit vectors of the three aerodynamic directions, obtaining the section force coefficient distribution of each blade at each span-wise position;
storing the distribution of the section force coefficient on each blade on the phase corresponding to the current physical time step of each blade;
and outputting the blade section force coefficient distribution of all phases as a blade disc load result.
8. A helicopter rotor disc load real-time generating device, comprising:
the discrete point generating module is used for generating section airfoil discrete points of each blade at different spanwise positions;
the interpolation relation calculation module is used for calculating and storing the interpolation relation between the object plane grid of each blade and the section airfoil discrete points;
the pressure coefficient acquisition module is used for acquiring pressure coefficients on the section airfoil discrete points of the blades at different spanwise positions in real time by utilizing unsteady CFD simulation according to the stored interpolation relation;
and the paddle load generation module is used for obtaining the section force distribution through integration according to the obtained pressure coefficient so as to generate a paddle load result.
9. A helicopter rotor disc load real-time generation apparatus comprising a processor and a memory, wherein said processor, when executing a computer program stored in said memory, implements a helicopter rotor disc load real-time generation method according to any one of claims 1 to 7.
10. A computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements a method for real-time generation of a helicopter rotor disc load according to any of claims 1 to 7.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116167303A (en) * | 2023-04-21 | 2023-05-26 | 中国空气动力研究与发展中心计算空气动力研究所 | Curved surface grid interpolation method for fluid-solid coupling simulation of helicopter rotor wing |
| CN117556548A (en) * | 2024-01-03 | 2024-02-13 | 中国空气动力研究与发展中心计算空气动力研究所 | Automatic calculation method applicable to paddle load foundation points of arbitrary grid surface |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104044736B (en) * | 2014-07-08 | 2016-04-13 | 天津宏泽天成科技有限公司 | Depopulated helicopter rotor blade tip |
| CN112199772A (en) * | 2020-09-25 | 2021-01-08 | 中国直升机设计研究所 | Helicopter rotor aerodynamic noise calculation method |
| CN113868779A (en) * | 2021-12-02 | 2021-12-31 | 中国空气动力研究与发展中心计算空气动力研究所 | Propeller aircraft blade flying-off safety assessment method based on multidisciplinary coupling simulation |
| CN114169068A (en) * | 2021-11-23 | 2022-03-11 | 中国直升机设计研究所 | Carrier landing flight characteristic analysis method suitable for coaxial rigid rotor helicopter |
| CN114756952A (en) * | 2022-02-17 | 2022-07-15 | 中国直升机设计研究所 | Calculation method for aerodynamic noise of helicopter rotor in hovering state |
-
2023
- 2023-02-13 CN CN202310101174.6A patent/CN115774903B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104044736B (en) * | 2014-07-08 | 2016-04-13 | 天津宏泽天成科技有限公司 | Depopulated helicopter rotor blade tip |
| CN112199772A (en) * | 2020-09-25 | 2021-01-08 | 中国直升机设计研究所 | Helicopter rotor aerodynamic noise calculation method |
| CN114169068A (en) * | 2021-11-23 | 2022-03-11 | 中国直升机设计研究所 | Carrier landing flight characteristic analysis method suitable for coaxial rigid rotor helicopter |
| CN113868779A (en) * | 2021-12-02 | 2021-12-31 | 中国空气动力研究与发展中心计算空气动力研究所 | Propeller aircraft blade flying-off safety assessment method based on multidisciplinary coupling simulation |
| CN114756952A (en) * | 2022-02-17 | 2022-07-15 | 中国直升机设计研究所 | Calculation method for aerodynamic noise of helicopter rotor in hovering state |
Non-Patent Citations (3)
| Title |
|---|
| QING\'AN LI 等: "Wind tunnel and numerical study of a straight-bladed vertical axis wind turbine in three-dimensional analysis (Part I: For predicting aerodynamic loads and performance)" * |
| 郭鑫 等: "基于解析位移形函数的改进风力机叶片梁单元" * |
| 韩伟 等: "高速旋转铰接式旋翼的固有特性分析" * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116167303A (en) * | 2023-04-21 | 2023-05-26 | 中国空气动力研究与发展中心计算空气动力研究所 | Curved surface grid interpolation method for fluid-solid coupling simulation of helicopter rotor wing |
| CN117556548A (en) * | 2024-01-03 | 2024-02-13 | 中国空气动力研究与发展中心计算空气动力研究所 | Automatic calculation method applicable to paddle load foundation points of arbitrary grid surface |
| CN117556548B (en) * | 2024-01-03 | 2024-05-14 | 中国空气动力研究与发展中心计算空气动力研究所 | Automatic calculation method applicable to paddle load foundation points of arbitrary grid surface |
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