CN111189611A - Wind tunnel test method based on strain type two-component surface friction resistance measuring balance - Google Patents
Wind tunnel test method based on strain type two-component surface friction resistance measuring balance Download PDFInfo
- Publication number
- CN111189611A CN111189611A CN202010173326.XA CN202010173326A CN111189611A CN 111189611 A CN111189611 A CN 111189611A CN 202010173326 A CN202010173326 A CN 202010173326A CN 111189611 A CN111189611 A CN 111189611A
- Authority
- CN
- China
- Prior art keywords
- measuring
- friction resistance
- surface friction
- balance
- hole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/06—Measuring arrangements specially adapted for aerodynamic testing
- G01M9/062—Wind tunnel balances; Holding devices combined with measuring arrangements
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The invention discloses a wind tunnel test method based on a strain type two-component surface friction resistance measuring balance. The balance used in the method is a special strain type two-component surface friction resistance measuring balance. The method comprises the following steps: processing a test model; mounting a balance protection shell, a connecting piece and a measuring piece on the surface friction resistance measuring balance to obtain a surface friction resistance measuring unit; a ground calibration surface friction resistance measurement unit; inputting a resistance calculation formula of the surface friction resistance measurement unit into a wind tunnel data acquisition system; mounting a surface friction resistance measuring unit on the model; adjusting the width of a gap between the test model and the measuring piece; adjusting the heights of the test model and the measuring part; installing a test model in the wind tunnel; adjusting the posture of the test model; and carrying out a wind tunnel test according to a conventional wind tunnel test process. The method is simple, convenient, easy to operate and high in test efficiency.
Description
Technical Field
The invention belongs to the technical field of wind tunnel tests, and particularly relates to a wind tunnel test method based on a strain type two-component surface friction resistance measurement balance.
Background
The surface friction resistance is the resultant force of the shearing force applied to the surface of the aircraft, is an important component of the aircraft resistance, and has great significance for the design of the aircraft for the accurate measurement of the aircraft resistance. Wind tunnel tests are an important method for obtaining the frictional resistance of the surface of an aircraft.
The surface friction resistance measurement technology in the wind tunnel has many difficulties: in order to reduce the damage to the surface of the wind tunnel test model, only a small-area surface can be measured, the friction resistance of the small-area surface is very small, and the measurement balance is required to have high enough resolution; the device is convenient to install and does not influence the structure of a test model, and the volume of a measuring balance is required to be small; because the flight direction of the real aircraft is inconsistent with the attitude of the aircraft and changes all the time, the total surface friction resistance can be synthesized only by measuring the surface friction resistance in two vertical directions; the normal load borne by the surface of the test model is far larger than the surface friction resistance, and the test model also needs to face the impact load in the process of switching a switch car in a hypersonic wind tunnel, so that the measurement balance needs to have higher structural rigidity and strength and has an overload protection function. The existing surface friction resistance balance is generally large in size and low in measurement resolution, can only be used for single-component measurement, and is difficult to solve the problems.
At present, a method for measuring the frictional resistance of the surface of the wind tunnel test needs to be developed.
Disclosure of Invention
The invention aims to solve the technical problem of providing a wind tunnel test method based on a strain type two-component surface friction resistance measuring balance.
The invention relates to a wind tunnel test method based on a strain type two-component surface friction resistance measuring balance, which is characterized in that the surface friction resistance measuring balance used in the wind tunnel test method is the strain type two-component surface friction resistance measuring balance, and the surface friction resistance measuring balance comprises the following components: the device comprises an upper connecting end, an X1 measuring beam, an X1 overload protection seam, an X2 overload protection seam, an X2 measuring beam, a fixed end and a rectangular positioning block;
the surface friction resistance measuring balance is of an integrated structure, and the main body is a cylinder;
the upper half part of the cylinder is provided with a through hole I and a through hole II which are bilaterally symmetrical, the upper side and the lower side of the through hole I and the through hole II are straight sides, the left side and the right side of the through hole I and the through hole II are arc sides, an entity reserved between the through hole I and the through hole II is an X1 measuring beam, the projection shapes of the upper section and the lower section of the X1 measuring beam are symmetrical arcs, and the projection shape of the middle section of the X1 measuring beam is a rectangle; entities reserved on the outer sides of the through hole I and the through hole II are separated through symmetrical straight seams respectively to form symmetrical X1 overload protection seams;
the lower half part of the cylinder is provided with a through hole III and a through hole IV which are symmetrical front and back, the upper sides and the lower sides of the through hole III and the through hole IV are straight sides, the left sides and the right sides of the through hole III and the through hole IV are arc sides, an entity reserved between the through hole III and the through hole IV is an X2 measuring beam, the projection shapes of the upper section and the lower section of the X2 measuring beam are symmetrical arcs, and the projection shape of the middle section of the X2 measuring beam is a rectangle; entities reserved outside the through hole III and the through hole IV are separated through symmetrical straight seams respectively to form symmetrical X2 overload protection seams;
the X1 measuring beam is vertical to the X2 measuring beam, and the X1 measuring beam and the X2 measuring beam respectively measure two vertical surface friction resistance components;
the center of the top end of the cylinder is provided with an upper connecting end;
the lower end of the cylinder is fixed with a fixed end, the diameter of the fixed end is larger than that of the cylinder, and the lower surface of the fixed end is fixed with a rectangular positioning block;
two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X1 measuring beam, the resistance strain gauges on one side are numbered A1 and A3, the resistance strain gauges on the other side are correspondingly numbered A2 and A4, and an X1 Wheatstone bridge is formed by the A1, the A2, the A3 and the A4; two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X2 measuring beam, the resistance strain gauges on one side are numbered as B1 and B3, the resistance strain gauges on the other side are correspondingly numbered as B2 and B4, and an X2 Wheatstone bridge is formed by B1, B2, B3 and B4;
a temperature sensor is arranged on the side surface of the fixed end;
the wind tunnel test method comprises the following steps:
a. processing a test model, selecting a measuring position on the outer surface of the test model, drilling a measuring hole at the measuring position according to the size of a measuring piece, wherein the hole diameter is slightly larger than the size of the measuring piece; a circular cavity for mounting the surface friction resistance measuring balance is designed below the measuring position; processing a measuring piece;
b. processing a connecting piece matched with the surface friction resistance measuring balance, wherein the upper surface of the connecting piece is a plane, the lower end of the connecting piece is provided with a vertical hole assembled with the upper connecting end, and the side wall of the connecting piece is provided with a horizontal screw hole; connecting the connecting piece with the upper connecting end in a matched manner through a column, and then fixing the connecting piece by tightening a set screw in a screw hole; fixedly mounting a measuring piece on the upper surface of the connecting piece;
c. processing and installing a balance protection shell matched with the round cavity of the test model, wherein the balance protection shell is of a cylindrical structure with a closed lower bottom, penetrates through a rectangular positioning block from bottom to top to cover the surface friction resistance measurement balance and a connecting piece, and the fixed end of the surface friction resistance measurement balance is in surface fit connection with the bottom surface of the balance protection shell; the balance protection shell, the surface friction resistance measuring balance, the connecting piece and the measuring piece form a whole to form a surface friction resistance measuring unit;
d. the ground calibration surface friction resistance measurement unit obtains the ground calibration coefficient K of the surface friction resistance measurement unit11And K12Voltage correction factor K21And K22Temperature correction coefficient K31And K32；
e. Inputting a resistance calculation formula of a surface friction resistance measurement balance into a wind tunnel data acquisition system, wherein the calculation formulas of two resistances X1 and X2 which are mutually vertical are as follows:
X1＝K21·K11·[UX1+K31·(T2-T1)]
X2＝K22·K12·[UX2+K32·(T2-T1)]
wherein, UX1Is the output voltage of an X1 Wheatstone bridge, UX2Is the output voltage of the X2 Wheatstone bridge; t is1Is an average initial value, T, of the measured values of temperature sensors mounted on the sides of the fixed ends2The average end value of the measured values of the temperature sensors arranged on the side of the fixed end is shown;
the resistance of the two components is subjected to orthogonal synthesis to obtain the total friction resistance:
f. installing a surface friction resistance measuring unit in the test model, and tensioning and fixing the surface friction resistance measuring unit through a countersunk head screw which is screwed on the lower surface of the test model from bottom to top;
g. detecting whether the upper surfaces of the test model and the measuring piece are in smooth transition or not, if steps exist, adjusting the height of the measuring piece by replacing connecting pieces with different thicknesses, and ensuring the smooth transition of the upper surfaces of the test model and the measuring piece;
h. measuring the width of a gap between the test model and the measuring piece, and adjusting the width of the gap to the required width of the gap by adjusting the position of the balance protective shell;
i. a test model is installed in the wind tunnel, the tail end of the test model is connected with a model supporting rod, and the model supporting rod is connected with a wind tunnel supporting mechanism;
j. connecting a balance line of the surface friction resistance measuring balance to a wind tunnel data acquisition system through the model supporting rod;
k. and adjusting the posture of the test model, and carrying out a wind tunnel test according to a conventional wind tunnel test process.
The width range of the X1 overload protection seam and the X2 overload protection seam is 0.08 mm-0.14 mm.
The surface friction resistance measuring balance is made of 7075 aluminum alloy and is treated by a T6 heat treatment process.
The thickness of the middle sections of the X1 measuring beam and the X2 measuring beam is 0.16-0.24 mm.
The width of a gap between the test model and the measuring piece is 0.06-0.2 mm.
In the wind tunnel test method based on the strain type two-component surface friction resistance measuring balance, the shear force acting on the measuring piece is transmitted to the surface friction resistance measuring balance through the connecting piece in the wind tunnel test process of the test model, so that the measuring beam is deformed, the Wheatstone bridge loses the original balance to generate a voltage signal increment, and the surface friction resistance of the measuring piece is obtained through a resistance calculation formula.
The surface friction resistance measuring balance in the wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is a two-component strain type surface friction resistance measuring balance, and is provided with an X1 measuring beam and an X2 measuring beam which are perpendicular to each other, wherein the X1 measuring beam and the X2 measuring beam respectively and independently measure two perpendicular surface friction resistance components, when a certain component load acts independently, only a Wheatstone bridge of the component has larger output, and the Wheatstone bridge of the other component basically has no output. The X1 measuring beam and the X2 measuring beam are designed according to the stress concentration principle, so that the rigidity is good, and the bridge output is large when the force is applied. The X1 overload protection seam and the X2 overload protection seam can play a role in limiting protection, and when the surface friction resistance measurement balance is stressed too much, the X1 overload protection seam or the X2 overload protection seam is closed, so that the surface friction resistance measurement balance is prevented from generating too much deformation.
According to the wind tunnel test method based on the strain type two-component surface friction resistance measurement balance, the surface friction resistance measurement balance is connected to the balance protection shell through the fixed end and the rectangular positioning block, so that the connection stress can be prevented from being transmitted to the surface friction resistance measurement balance, and the reliability of the surface friction resistance measurement balance is improved.
The balance protection shell in the wind tunnel test method based on the strain type two-component surface friction resistance measurement balance can play a role in protecting the balance, isolating internal airflow, fixing a measurement line and connecting with a test model.
The connecting piece in the wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is arranged between the measuring piece and the surface friction resistance measuring balance, so that the surface friction resistance measuring balance can adapt to a plurality of measuring pieces of different types, and the positions of the measuring pieces are convenient to replace and adjust.
The surface friction resistance measuring balance in the wind tunnel test method based on the strain type two-component surface friction resistance measuring balance can realize accurate measurement of the surface friction resistance of the test model, and has very high resolution, the typical range is 0.02N, and the minimum resolution can be 0.0002N.
The diameter of the surface friction resistance measuring balance in the wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is equivalent to the size of a measuring part, the rigidity along the normal direction of the measuring surface is high, the overload protection function is realized, the method not only can be used for measuring the surface friction resistance of a test model in the wind tunnel test, but also can be used for directly measuring the surface friction resistance of an aircraft on the aircraft, and the method has high popularization and application values.
The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is simple, convenient, easy to operate and high in test efficiency.
Drawings
FIG. 1 is an isometric view of a strain-type two-component surface friction resistance measuring balance of the present invention;
FIG. 2 is a front view of a strain-type two-component surface frictional resistance measuring balance according to the present invention;
FIG. 3 is a left side view of a strain-type two-component surface frictional resistance measuring balance according to the present invention;
FIG. 4 is a top view of a strain-type two-component surface frictional resistance measuring balance of the present invention;
FIG. 5 is a bottom view of a strain-type two-component surface friction resistance measuring balance of the present invention;
FIG. 6a is the sticking position of the strain gauge of the X1 measuring beam of the balance for measuring surface frictional resistance in strain type two-component in accordance with the present invention;
FIG. 6b is an X1 Wheatstone bridge of the strain-type two-component surface frictional resistance measuring balance of the present invention;
FIG. 6c is a diagram showing the sticking positions of the strain gauges of the X2 measuring beam of the balance for measuring two-component surface frictional resistance according to the present invention;
FIG. 6d is an X2 Wheatstone bridge of the strain-type two-component surface frictional resistance measuring balance of the present invention;
FIG. 7 is a schematic diagram of a wind tunnel test method based on a strain type two-component surface friction resistance measurement balance in the invention.
In the figure, 1, a test model 2, a measuring piece 3, a surface friction resistance measuring balance 4, a connecting piece 5, a set screw 6, a balance protective shell 7, an upper connecting end 8, an X1 measuring beam 9, an X1 overload protection seam 10, an X2 overload protection seam 11, an X2 measuring beam 12 and a fixed end 13 are rectangular positioning blocks;
the X1 wheatstone bridge has strain gage numbers: a1, a2, A3, a 4; the X2 wheatstone bridge has strain gage numbers: b1, B2, B3 and B4.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and examples.
As shown in fig. 1 to 5, the wind tunnel test method based on the strain type two-component surface friction resistance measurement balance of the present invention is characterized in that the surface friction resistance measurement balance used in the wind tunnel test method is a strain type two-component surface friction resistance measurement balance, and the surface friction resistance measurement balance 3 includes: the device comprises an upper connecting end 7, an X1 measuring beam 8, an X1 overload protection seam 9, an X2 overload protection seam 10, an X2 measuring beam 11, a fixed end 12 and a rectangular positioning block 13;
the surface friction resistance measuring balance 3 is of an integrated structure, and the main body is a cylinder;
the upper half part of the cylinder is provided with a through hole I and a through hole II which are bilaterally symmetrical, the upper sides and the lower sides of the through hole I and the through hole II are straight sides, the left sides and the right sides of the through hole I and the through hole II are arc sides, an entity reserved between the through hole I and the through hole II is an X1 measuring beam 8, the projection shapes of the upper section and the lower section of the X1 measuring beam 8 are symmetrical arcs, and the projection shape of the middle section of the X1 measuring beam 8 is a rectangle; entities reserved outside the through hole I and the through hole II are separated through symmetrical straight seams respectively to form a symmetrical X1 overload protection seam 9;
the lower half part of the cylinder is provided with a through hole III and a through hole IV which are symmetrical front and back, the upper sides and the lower sides of the through hole III and the through hole IV are straight sides, the left sides and the right sides of the through hole III and the through hole IV are arc sides, an entity reserved between the through hole III and the through hole IV is an X2 measuring beam 11, the projection shapes of the upper section and the lower section of the X2 measuring beam 11 are symmetrical arcs, and the projection shape of the middle section of the X2 measuring beam 11 is a rectangle; entities reserved outside the through hole III and the through hole IV are separated through symmetrical straight seams respectively to form a symmetrical X2 overload protection seam 10;
the X1 measuring beam 8 is vertical to the X2 measuring beam 11, and the X1 measuring beam 8 is vertical to the X2 measuring beam 11 to measure two vertical surface friction resistance components respectively;
the center of the top end of the cylinder is provided with an upper connecting end 7;
a fixed end 12 is fixed at the lower end of the cylinder, the diameter of the fixed end 12 is larger than that of the cylinder, and a rectangular positioning block 13 is fixed on the lower surface of the fixed end 12;
as shown in fig. 6a to 6d, two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X1 measuring beam 8, the resistance strain gauges on one side are numbered as a1 and A3, the resistance strain gauges on the other side are correspondingly numbered as a2 and a4, and an X1 wheatstone bridge is formed by a1, a2, A3 and a 4; two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X2 measuring beam 11, the resistance strain gauges on one side are numbered as B1 and B3, the resistance strain gauges on the other side are correspondingly numbered as B2 and B4, and an X2 Wheatstone bridge is formed by the B1, the B2, the B3 and the B4;
a temperature sensor is arranged on the side surface of the fixed end 12;
the wind tunnel test method comprises the following steps:
a. processing the test model 1, selecting a measuring position on the outer surface of the test model 1, drilling a measuring hole at the measuring position according to the size of the measuring piece 2, wherein the aperture is slightly larger than the size of the measuring piece 2; a round cavity for mounting the surface friction resistance measuring balance 3 is designed below the measuring position; processing a measuring piece;
b. processing a connecting piece 4 matched with the surface friction resistance measuring balance 3, wherein the upper surface of the connecting piece 4 is a plane, the lower end of the connecting piece 4 is provided with a vertical hole assembled with the upper connecting end 7, and the side wall of the connecting piece 4 is provided with a horizontal screw hole; the connecting piece 4 is matched and connected with the upper connecting end 7 through a column, and then is fixed by tightening a set screw 5 in a screw hole; the measuring piece 2 is fixedly arranged on the upper surface of the connecting piece 4;
c. processing and installing a balance protection shell 6 matched with the round cavity of the test model 1, wherein the balance protection shell 6 is of a cylindrical structure with a closed lower bottom, penetrates through a rectangular positioning block 13 from bottom to top to cover a surface friction resistance measurement balance 3 and a connecting piece 4, and a fixed end 12 of the surface friction resistance measurement balance 3 is in surface fit connection with the bottom surface of the balance protection shell 6; the balance protective shell 6, the surface friction resistance measuring balance 3, the connecting piece 4 and the measuring piece 2 form a whole to form a surface friction resistance measuring unit;
d. the ground calibration surface friction resistance measurement unit obtains the ground calibration coefficient K of the surface friction resistance measurement unit11And K12Voltage correction factor K21And K22Temperature correction coefficient K31And K32；
e. Inputting a resistance calculation formula of the surface friction resistance measuring balance 3 into a wind tunnel data acquisition system, wherein the calculation formulas of two resistances X1 and X2 which are mutually vertical are as follows:
X1＝K21·K11·[UX1+K31·(T2-T1)]
X2＝K22·K12·[UX2+K32·(T2-T1)]
wherein, UX1Is the output voltage of an X1 Wheatstone bridge, UX2Is the output voltage of the X2 Wheatstone bridge; t is1Is an average initial value, T, of the measured values of the temperature sensors mounted on the side of the fixed end 122Is the average end value of the measured values of the temperature sensors mounted on the side of the fixed end 12;
the resistance of the two components is subjected to orthogonal synthesis to obtain the total friction resistance:
f. installing a surface friction resistance measuring unit in the test model 1, and tightening and fixing the surface friction resistance measuring unit through a countersunk head screw screwed on the lower surface of the test model 1 from bottom to top;
g. detecting whether the upper surfaces of the test model 1 and the measuring piece 2 are in smooth transition or not, if a step exists, adjusting the height of the measuring piece 2 by replacing connecting pieces 4 with different thicknesses, and ensuring the smooth transition of the upper surfaces of the test model 1 and the measuring piece 2;
h. measuring the width of a gap between the test model 1 and the measuring part 2, and adjusting the width of the gap to the required width of the gap by adjusting the position of the balance protective shell 6;
i. a test model 1 is installed in the wind tunnel, the tail end of the test model 1 is connected with a model supporting rod, and the model supporting rod is connected with a wind tunnel supporting mechanism;
j. a balance line of the surface friction resistance measuring balance 3 is connected to the wind tunnel data acquisition system through the model supporting rod;
k. and adjusting the posture of the test model 1, and carrying out a wind tunnel test according to a conventional wind tunnel test process.
The width range of the X1 overload protection seam 9 and the X2 overload protection seam 10 is 0.08 mm-0.14 mm.
The surface friction resistance measuring balance 3 is made of 7075 aluminum alloy and is treated by a T6 heat treatment process.
The thickness of the middle sections of the X1 measuring beam 8 and the X2 measuring beam 11 is 0.16-0.24 mm.
The width of the gap between the test model 1 and the measuring piece 2 is 0.06-0.2 mm.
Example 1
The test wind tunnel of the embodiment is a hypersonic wind tunnel, the test model 1 is a flat plate model, the lower surface of the front edge of the test model 1 is provided with a wedge facing to the wind tunnel, and the upper surface of the measuring part 2 is a horizontal plane;
before the wind tunnel test, the width of a gap between the test model 1 and the measuring part 2 is measured, and the width of the gap is adjusted to the required width of the gap by adjusting the position of the balance protective shell 6;
before the wind tunnel test, the upper surface heights of the test model 1 and the measuring part 2 are measured, if the upper surfaces of the test model 1 and the measuring part 2 are not on the same horizontal plane, the height of the measuring part 2 is adjusted by replacing connecting pieces 4 with different thicknesses, and the upper surfaces of the test model 1 and the measuring part 2 are ensured to be located on the same horizontal plane.
According to the measurement requirements, a plurality of surface friction resistance measurement units are additionally arranged on the test model 1, and the surface friction resistance of different measurement positions on the surface of the test model 1 is obtained.
Claims (5)
1. The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is characterized in that the surface friction resistance measuring balance used in the wind tunnel test method is the strain type two-component surface friction resistance measuring balance, and the surface friction resistance measuring balance (3) comprises the following components: the device comprises an upper connecting end (7), an X1 measuring beam (8), an X1 overload protection seam (9), an X2 overload protection seam (10), an X2 measuring beam (11), a fixed end (12) and a rectangular positioning block (13);
the surface friction resistance measuring balance (3) is of an integrated structure, and the main body is a cylinder;
the upper half part of the cylinder is provided with a through hole I and a through hole II which are bilaterally symmetrical, the upper side and the lower side of the through hole I and the through hole II are straight sides, the left side and the right side of the through hole I and the through hole II are arc sides, an entity reserved between the through hole I and the through hole II is an X1 measuring beam (8), the projection shapes of the upper section and the lower section of the X1 measuring beam (8) are symmetrical arcs, and the projection shape of the middle section of the X1 measuring beam (8) is a rectangle; entities reserved on the outer sides of the through hole I and the through hole II are separated through symmetrical straight seams respectively to form symmetrical X1 overload protection seams (9);
the lower half part of the cylinder is provided with a through hole III and a through hole IV which are symmetrical front and back, the upper sides and the lower sides of the through hole III and the through hole IV are straight sides, the left sides and the right sides of the through hole III and the through hole IV are arc sides, an entity reserved between the through hole III and the through hole IV is an X2 measuring beam (11), the projection shapes of the upper section and the lower section of the X2 measuring beam (11) are symmetrical arcs, and the projection shape of the middle section of the X2 measuring beam (11) is a rectangle; entities reserved outside the through hole III and the through hole IV are separated through symmetrical straight seams respectively to form a symmetrical X2 overload protection seam (10);
the X1 measuring beam (8) is vertical to the X2 measuring beam (11), and the X1 measuring beam (8) and the X2 measuring beam (11) respectively measure two vertical surface friction resistance components;
the center of the top end of the cylinder is provided with an upper connecting end (7);
a fixed end (12) is fixed at the lower end of the cylinder, the diameter of the fixed end (12) is larger than that of the cylinder, and a rectangular positioning block (13) is fixed on the lower surface of the fixed end (12);
two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X1 measuring beam (8), the resistance strain gauges on one side are numbered A1 and A3, the resistance strain gauges on the other side are correspondingly numbered A2 and A4, and an X1 Wheatstone bridge is formed by the resistance strain gauges on the A1, the resistance strain gauges on the A2, the resistance strain gauges on the A3 and the resistance strain gauges on the A4; two parallel resistance strain gauges are symmetrically adhered to two sides of the middle position of the middle section of the X2 measuring beam (11), the resistance strain gauges on one side are numbered as B1 and B3, the resistance strain gauges on the other side are correspondingly numbered as B2 and B4, and an X2 Wheatstone bridge is formed by the B1, the B2, the B3 and the B4;
a temperature sensor is arranged on the side surface of the fixed end (12);
the wind tunnel test method comprises the following steps:
a. processing the test model (1), selecting a measuring position on the outer surface of the test model (1), drilling a measuring hole at the measuring position according to the size of the measuring piece (2), wherein the hole diameter is slightly larger than the size of the measuring piece (2); a round cavity for installing a surface friction resistance measuring balance (3) is designed below the measuring position; processing a measuring piece;
b. processing a connecting piece (4) matched with the surface friction resistance measuring balance (3), wherein the upper surface of the connecting piece (4) is a plane, the lower end of the connecting piece (4) is provided with a vertical hole assembled with the upper connecting end (7), and the side wall of the connecting piece (4) is provided with a horizontal screw hole; the connecting piece (4) is matched and connected with the upper connecting end (7) through a column, and then the connecting piece is fixed by tightening a set screw (5) in a screw hole; the measuring piece (2) is fixedly arranged on the upper surface of the connecting piece (4);
c. processing and installing a balance protection shell (6) matched with the round cavity of the test model (1), wherein the balance protection shell (6) is of a cylindrical structure with a closed lower bottom, penetrates through a rectangular positioning block (13) from bottom to top to cover a surface friction resistance measurement balance (3) and a connecting piece (4), and a fixed end (12) of the surface friction resistance measurement balance (3) is in surface fit connection with the bottom surface of the balance protection shell (6); the balance protective shell (6), the surface friction resistance measuring balance (3), the connecting piece (4) and the measuring piece (2) form a whole to form a surface friction resistance measuring unit;
d. the ground calibration surface friction resistance measurement unit obtains the ground calibration coefficient K of the surface friction resistance measurement unit11And K12Voltage correction factor K21And K22Temperature correction coefficient K31And K32；
e. Inputting a resistance calculation formula of the surface friction resistance measuring balance (3) into a wind tunnel data acquisition system, wherein the calculation formula of two resistances X1 and X2 which are perpendicular to each other is as follows:
X1＝K21·K11·[UX1+K31·(T2-T1)]
X2＝K22·K12·[UX2+K32·(T2-T1)]
wherein, UX1Is the output voltage of an X1 Wheatstone bridge, UX2Is the output voltage of the X2 Wheatstone bridge; t is1Is an average initial value, T, of the measured values of a temperature sensor arranged on the side of the fixed end (12)2Is the average end value of the measured values of the temperature sensors arranged on the side of the fixed end (12);
the resistance of the two components is subjected to orthogonal synthesis to obtain the total friction resistance:
f. installing a surface friction resistance measuring unit in the test model (1), and tightening and fixing the surface friction resistance measuring unit through a countersunk head screw screwed on the lower surface of the test model (1) from bottom to top;
g. detecting whether the upper surfaces of the test model (1) and the measuring piece (2) are in smooth transition or not, if a step exists, adjusting the height of the measuring piece (2) by replacing connecting pieces (4) with different thicknesses, and ensuring the smooth transition of the upper surfaces of the test model (1) and the measuring piece (2);
h. measuring the width of a gap between the test model (1) and the measuring piece (2), and adjusting the width of the gap to the required width of the gap by adjusting the position of the balance protective shell (6);
i. a test model (1) is installed in the wind tunnel, the tail end of the test model (1) is connected with a model supporting rod, and the model supporting rod is connected with a wind tunnel supporting mechanism;
j. a balance line of the surface friction resistance measuring balance (3) penetrates through the model support rod to be connected to the wind tunnel data acquisition system;
k. and adjusting the posture of the test model (1), and carrying out a wind tunnel test according to a conventional wind tunnel test process.
2. The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance according to claim 1, wherein the width of the X1 overload protection slit (9) and the X2 overload protection slit (10) ranges from 0.08mm to 0.14 mm.
3. The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance according to claim 1, wherein the surface friction resistance measuring balance (3) is made of 7075 aluminum alloy and is treated by a T6 heat treatment process.
4. The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance according to claim 1, wherein the thickness of the middle section of the X1 measuring beam (8) and the X2 measuring beam (11) is 0.16 mm-0.24 mm.
5. The wind tunnel test method based on the strain type two-component surface friction resistance measuring balance is characterized in that the width of a gap between the test model (1) and the measuring piece (2) is 0.06-0.2 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010173326.XA CN111189611B (en) | 2020-03-13 | 2020-03-13 | Wind tunnel test method based on strain type two-component surface friction resistance measuring balance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010173326.XA CN111189611B (en) | 2020-03-13 | 2020-03-13 | Wind tunnel test method based on strain type two-component surface friction resistance measuring balance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111189611A true CN111189611A (en) | 2020-05-22 |
| CN111189611B CN111189611B (en) | 2021-05-25 |
Family
ID=70706878
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010173326.XA Active CN111189611B (en) | 2020-03-13 | 2020-03-13 | Wind tunnel test method based on strain type two-component surface friction resistance measuring balance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111189611B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111157220A (en) * | 2020-03-13 | 2020-05-15 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain type two-component surface friction resistance measuring balance |
| CN112461494A (en) * | 2020-11-09 | 2021-03-09 | 中国空气动力研究与发展中心 | Pulse combustion wind tunnel model support-balance integrated force measuring device |
| CN114001909A (en) * | 2021-11-09 | 2022-02-01 | 中国空气动力研究与发展中心超高速空气动力研究所 | Displacement element for wind tunnel roll dynamic derivative test and design method thereof |
| CN117245196A (en) * | 2023-11-16 | 2023-12-19 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain balance electron beam welding structure and welding method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL97982A (en) * | 1991-04-28 | 1995-10-31 | Israel Aircraft Ind Ltd | Internal balance calibration system and method |
| CN206410842U (en) * | 2016-08-26 | 2017-08-15 | 哈尔滨工业大学深圳研究生院 | The force balance of tiny area windage resistance in a kind of measurement Boundary Layer on Flat Plate |
| CN108692912A (en) * | 2018-04-28 | 2018-10-23 | 中国空气动力研究与发展中心超高速空气动力研究所 | A kind of double frictional resistance balance measurement methods of swimming cloths |
| CN110132526A (en) * | 2019-05-29 | 2019-08-16 | 中国科学院力学研究所 | A kind of low disturbing pulse type shock tunnel strain type face frictional resistance balance |
| CN110595725A (en) * | 2019-09-26 | 2019-12-20 | 中国空气动力研究与发展中心高速空气动力研究所 | Transverse jet flow four-component tube type wind tunnel balance |
-
2020
- 2020-03-13 CN CN202010173326.XA patent/CN111189611B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IL97982A (en) * | 1991-04-28 | 1995-10-31 | Israel Aircraft Ind Ltd | Internal balance calibration system and method |
| CN206410842U (en) * | 2016-08-26 | 2017-08-15 | 哈尔滨工业大学深圳研究生院 | The force balance of tiny area windage resistance in a kind of measurement Boundary Layer on Flat Plate |
| CN108692912A (en) * | 2018-04-28 | 2018-10-23 | 中国空气动力研究与发展中心超高速空气动力研究所 | A kind of double frictional resistance balance measurement methods of swimming cloths |
| CN110132526A (en) * | 2019-05-29 | 2019-08-16 | 中国科学院力学研究所 | A kind of low disturbing pulse type shock tunnel strain type face frictional resistance balance |
| CN110595725A (en) * | 2019-09-26 | 2019-12-20 | 中国空气动力研究与发展中心高速空气动力研究所 | Transverse jet flow four-component tube type wind tunnel balance |
Non-Patent Citations (1)
| Title |
|---|
| 马洪强等: "高超声速摩擦阻力直接测量实验研究", 《实验流体力学》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111157220A (en) * | 2020-03-13 | 2020-05-15 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain type two-component surface friction resistance measuring balance |
| CN111157220B (en) * | 2020-03-13 | 2024-03-26 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain type two-component surface friction resistance measuring balance |
| CN112461494A (en) * | 2020-11-09 | 2021-03-09 | 中国空气动力研究与发展中心 | Pulse combustion wind tunnel model support-balance integrated force measuring device |
| CN114001909A (en) * | 2021-11-09 | 2022-02-01 | 中国空气动力研究与发展中心超高速空气动力研究所 | Displacement element for wind tunnel roll dynamic derivative test and design method thereof |
| CN117245196A (en) * | 2023-11-16 | 2023-12-19 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain balance electron beam welding structure and welding method thereof |
| CN117245196B (en) * | 2023-11-16 | 2024-01-23 | 中国空气动力研究与发展中心高速空气动力研究所 | Strain balance electron beam welding structure and welding method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111189611B (en) | 2021-05-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111189611B (en) | Wind tunnel test method based on strain type two-component surface friction resistance measuring balance | |
| US10126186B2 (en) | Load transducer system configured to correct for measurement errors in the output forces and/or moments of the system | |
| CN111175016B (en) | Surface friction resistance wind tunnel measuring method based on box type friction resistance balance | |
| US9032817B2 (en) | Low profile load transducer | |
| CN111504596B (en) | Hinge moment balance | |
| US10823603B2 (en) | Symmetric load cell with mounting effect cancellation | |
| US20050211003A1 (en) | Foil strain gage | |
| CN104990683A (en) | A segmented trace hinge moment balance | |
| CN106525385B (en) | Model integrated horizontal vertical tail aerodynamic force measuring device | |
| JPS604417B2 (en) | strain gauge converter | |
| RU2287795C1 (en) | Device for measurement of aerodynamic force vector's components and of moment | |
| CN108613764A (en) | A kind of primary structure member and the strain transducer with the primary structure member | |
| EP1288636B1 (en) | Electronic balance | |
| US5962818A (en) | Top scale balance | |
| US3646809A (en) | Adjustable transducer overload stop | |
| CN211262655U (en) | Strain type two-component surface friction resistance measuring balance | |
| EP0800069A1 (en) | Column force transducer | |
| CN218955677U (en) | Resistive surface strain sensor | |
| CN111157220B (en) | Strain type two-component surface friction resistance measuring balance | |
| US9074926B2 (en) | Electronic balance with windproof case and electrically conductive structure | |
| CN103419165A (en) | High-precision torque wrench and checkout, installation and detection method thereof | |
| CN209512823U (en) | A kind of reusable bolt load sensor | |
| CN112362216A (en) | Engine six-component force measuring device adopting double measuring systems | |
| CN114646451B (en) | Balance with double fixed supporting parts | |
| US7086299B2 (en) | Multi-load beam apparatus to prevent improper operation due to off-axis loads |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |