CN113465872B - Hot wire anemometer suitable for high-speed flow field measurement - Google Patents
Hot wire anemometer suitable for high-speed flow field measurement Download PDFInfo
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- CN113465872B CN113465872B CN202110734124.2A CN202110734124A CN113465872B CN 113465872 B CN113465872 B CN 113465872B CN 202110734124 A CN202110734124 A CN 202110734124A CN 113465872 B CN113465872 B CN 113465872B
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- 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
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
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Abstract
The invention discloses a hot wire anemometer suitable for high-speed flow field measurement, which comprises a sensor comprehensive measuring frame (1-0), a programmable logic control intelligent hot wire anemometer (2-0) and a sensor signal wire (3-0). The hot wire anemometer adopts the programmable logic controller to control the whole system to realize the rapid measurement and setting of sensor parameters, intelligently adjusts the working parameters of the hot wire overheat ratio, synchronously measures the vibration and static pressure pulsation signals of the comprehensive measuring frame, processes the coupling interference signals of the measurement signals of the hot wire probe, can solve the problems of bracket vibration, static pressure pulsation interference caused by compressible flow and the like in the measurement of a high-speed flow field, can obviously improve the measurement precision of the hot wire in the high-speed flow field by 20 percent, and shortens the measurement time by 70 percent.
Description
Technical Field
The invention belongs to the technical field of flow field testing, and particularly relates to a hot wire anemometer suitable for high-speed flow field measurement.
Background
The hot wire anemometer is common equipment in the technical field of flow field testing, is commonly used for measuring the fluid speed and the turbulence, is the most main means for measuring the turbulence of a wind tunnel flow field, is particularly widely applied to a low-speed flow field, and is a standard method for measuring the turbulence of the low-speed wind tunnel flow field, but in a high-speed wind tunnel, along with the increase of the flow field speed, the hot wire anemometer technology faces various problems of vibration interference, multi-parameter decoupling of a compressible flow field and the like, so that the application difficulty of the hot wire in the high-speed flow field is great. Currently, with the increase of the demand of high-speed aircrafts, the demand of people on the turbulence mechanism and measurement of the high-speed flow field of the wind tunnel is increasingly prominent, so that the problem of effectively measuring the turbulence of the high-speed flow field of the wind tunnel is urgently needed to be solved.
The conventional hot wire instrument generally only has a hot wire probe and an ambient temperature measuring channel, and can not synchronously measure interference signals such as coupled vibration, static pressure pulsation and the like in a high-speed flow field, so that the problem of multi-parameter decoupling in the high-speed flow field is difficult to solve. In addition, the conventional hot wire instrument generally performs parameter setting, control and data sampling through an upper computer, so that the measurement process is slow, the measurement time is long, the wind tunnel operation cost is high, and the measurement method is even a completely infeasible measurement means for a temporary flushing wind tunnel with short operation time.
Therefore, in order to improve the test accuracy and reliability of the high-speed flow field hot wire technology, a hot wire anemometer suitable for high-speed flow field measurement is required.
Disclosure of Invention
The invention aims to solve the technical problem of providing a hot wire anemometer suitable for high-speed flow field measurement, which comprises a sensor comprehensive measuring frame (1-0), a programmable logic control intelligent hot wire anemometer (2-0) and a sensor signal wire (3-0). The hot wire anemometer adopts the programmable logic control module to control the whole system to realize the rapid measurement and setting of sensor parameters, intelligently adjusts the working parameters of the hot wire overheat ratio, synchronously measures the vibration and static pressure pulsation signals of the comprehensive measuring frame, processes the coupling interference signals of the measurement signals of the hot wire probe, can solve the problems of bracket vibration, static pressure pulsation interference caused by compressible flow and the like in the measurement of a high-speed flow field, and effectively improves the measurement precision of the hot wire in the high-speed flow field.
The invention solves the technical problems by adopting the technical scheme that: a hot wire anemometer adapted for high speed flow field measurement, the anemometer comprising: the intelligent hot wire anemometer comprises a sensor comprehensive measurement frame (1-0), a programmable logic control intelligent hot wire anemometer (2-0), a sensor signal wire (3-0), wherein the sensor signal wire (3-0) is communicated with the sensor comprehensive measurement frame (1-0) and the programmable logic control intelligent hot wire anemometer (2-0);
the comprehensive sensor measuring frame (1-0) consists of a hot wire probe (1-1), an acceleration sensor (1-2), a pulse pressure sensor (1-3) and a mounting frame, wherein the hot wire probe (1-1), the acceleration sensor (1-2) and the pulse pressure sensor (1-3) are arranged on the mounting frame;
the programmable logic control intelligent hot wire anemometer (2-0) consists of an acceleration sensor signal conditioning and collecting module (2-1), a hot wire signal conditioning and collecting module (2-2), a programmable logic controller (2-3), a pulse pressure sensor signal conditioning and collecting module (2-4), a lithium battery-based signal excitation and power supply module (2-5), a data storage module (2-6), a communication and expansion control module (2-7), a communication and expansion interface (2-8) and a sensor input signal interface (2-9); the sensor input signal interfaces (2-9) comprise three signal input ends which are respectively connected with the acceleration sensor signal conditioning and collecting module (2-1), the hot wire signal conditioning and collecting module (2-2) and the pulse pressure sensor signal conditioning and collecting module (2-4); the signal output ends of the acceleration sensor signal conditioning and collecting module (2-1), the hot wire signal conditioning and collecting module (2-2) and the pulse pressure sensor signal conditioning and collecting module (2-4) are connected with the programmable logic controller (2-3); the programmable logic controller (2-3) is connected with the data storage module (2-6) and the communication and expansion control module (2-7) through a data line, and is powered by the signal excitation and power supply module (2-5) based on a lithium battery; the communication and expansion control module (2-7) is connected with the communication and expansion interface (2-8);
the programmable logic controller (2-3) is added into the data operation of the hot wire signal conditioning acquisition module (2-2) by measuring the output signals of the acceleration sensor signal conditioning acquisition module (2-1) and the pulse pressure sensor signal conditioning acquisition module (2-4), so that the measurement accuracy of the wind speed and the turbulence is improved, and the method for calculating the wind speed and the turbulence is as follows:
step 1: carrying out frequency spectrum analysis on the output signal of the signal conditioning acquisition module (2-1) of the acceleration sensor to obtain the vibration frequency of the comprehensive sensor measuring frame (1-0);
step 2: according to the vibration frequency of the sensor comprehensive measurement frame (1-0), the output signal of the hot wire signal conditioning and collecting module (2-2) is processed by adopting a decorrelation algorithm, so that the interference signal of the vibration of the sensor comprehensive measurement frame (1-0) caused by a high-speed flow field is reduced;
step 3: the programmable logic controller (2-3) acquires a flow field static pressure pulsation signal near the hot wire probe from the pulsation pressure sensor signal conditioning acquisition module (2-4) and is used for correcting an output signal of the hot wire signal conditioning acquisition module (2-2) so as to improve speed measurement precision, and a wind speed calculation formula is as follows:
wherein E is a hot wire output voltage signal; r is the flow field gas constant; t is the static temperature of the flow field; k is the sensitivity coefficient of the heat ray convection field flow; p is a static pressure value of a flow field near the hot wire probe measured by the pulse pressure sensor signal conditioning acquisition module (2-4);
step 4: the programmable logic controller (2-3) calculates the flow field turbulence Q by measuring the flow pulsation value, static pressure and temperature change of the flow field, and the formula is as follows:
wherein: u is flow field velocity, ρ is flow field density, P is flow field static pressure, T' 0 Is the root mean square deviation of the total temperature pulsation of the flow field,is the flow field total temperature pulsation mean value +.>Is the flow field total temperature pulsation value,/->Is the flow field mass flow pulsation value,/->Is the correlation coefficient of flow field mass flow and total temperature, gamma is the gas specific heat ratio, M is the flow field Mach number.
Further, in the sensor comprehensive measuring frame (1-0), the hot wire probe (1-1) is arranged in the middle of the mounting frame, and the acceleration sensor (1-2) and the pulse pressure sensor (1-3) are respectively arranged on two sides of the hot wire probe (1-1).
The invention has the beneficial effects that:
the hot wire anemometer suitable for high-speed flow field measurement comprises a sensor comprehensive measurement frame, a programmable logic control intelligent hot wire anemometer and a sensor signal wire, can quickly adjust overheat ratio and response frequency parameters according to hot wire resistance static parameters under the influence of local flow field speed and temperature, synchronously measures to obtain a hot wire probe signal, a bracket vibration signal and a static pressure pulsation signal, decouples to obtain flow field turbulence measurement, temperature pulsation amount and density pulsation amount, and improves measurement accuracy of a hot wire test technology in a high-speed flow field. The invention aims at meeting the hot wire test of the high-speed wind tunnel and provides design reference for expanding the application of the hot wire test technology in the high-speed flow field.
Drawings
FIG. 1 is a schematic diagram of a hot wire anemometer suitable for high-speed flow field measurement;
in the figure: 1-0, a sensor comprehensive measuring frame, 2-0, a programmable logic control intelligent hot wire anemometer and 3-0, a sensor signal wire.
FIG. 2 is a schematic diagram of the structure of the sensor comprehensive measuring rack;
in the figure: 1-1, a hot wire probe, 1-2, an acceleration sensor and 1-3, a pulse pressure sensor.
FIG. 3 is a schematic diagram of a programmable logic control intelligent hot wire anemometer architecture;
in the figure: 2-1 parts of acceleration sensor signal conditioning and collecting module, 2-2 parts of hot wire signal conditioning and collecting module, 2-3 parts of programmable logic controller, 2-4 parts of pulse pressure sensor signal conditioning and collecting module, 2-5 parts of lithium battery-based signal excitation and power supply module, 2-6 parts of data storage module, 2-7 parts of communication and expansion control module, 2-8 parts of communication and expansion interface and 2-9 parts of sensor input signal interface.
Detailed Description
FIGS. 1, 2 and 3 are schematic views of a hot wire anemometer adapted for high speed flow field measurement in accordance with the present invention. FIG. 1 is a general structural diagram of a hot wire instrument, FIG. 2 is a schematic diagram of a sensor comprehensive measuring rack structure, and FIG. 3 is a schematic diagram of a programmable logic control intelligent hot wire anemometer structure. The acceleration sensor and the pulsation pressure sensor of the sensor integrated measuring frame (1-0) are auxiliary measuring sensors, the acceleration sensor measures the obtained vibration signals, and the static pressure pulsation signals obtained by the measurement of the pulsation pressure sensor are used for decoupling corresponding vibration and density pulsation interference signals in the hot wire probe; the programmable logic controller is realized by adopting a programmable logic chip, and can independently control each module to finish the work of hot wire parameter measurement, parameter setting, analog channel response frequency measurement, analog channel response frequency compensation, continuous variable overheat ratio measurement, instrument background noise measurement, interference signal decoupling, data synchronous acquisition, data storage, transmission and the like.
The design indexes of the hot wire anemometer are as follows:
resistance range of cold wire probe: 0 to 10Ohm;
resistance range of hot wire probe: 0 to 20Ohm;
maximum current of probe: 800mA;
resistance measurement accuracy: 0.01Ohm;
probe signal line length: more than or equal to 50m;
hot line channel bandwidth: better than DC-200kHz;
built-in low-pass 4 th order butterworth filter, cut-off frequency: 0.3/1/3/10/30/50/100/200/300kHz (+ -3 dB);
signal line interface: BNCs;
temperature drift: less than 20 μV/°C (@ 5V);
noise floor: less than 35 nV/. Cndot.Hz (@ 1 kHz);
AD resolution: not less than 24 bits;
AD sampling rate: more than or equal to 400KHz;
dual mode operating power supply, mode one: 220V,50Hz; mode two: supplying power to a lithium battery;
hotline sensor measurement channel: 8 channels;
noise vibration measurement channel: 2 channels, ICP excitation;
temperature sensor: the frequency response is more than or equal to 2KHz, the precision is 0.1 ℃, and the temperature range is as follows: -15 to 65 ℃;
noise (pulsating pressure) sensor: ICP excitation, measuring range 25psi, frequency response 5Hz-20kHz, precision 2%, temperature range: -15 to 65 ℃;
acceleration sensor: ICP excitation, measuring range 50g, sensitivity 100mV/g, precision 1%, temperature range: -15 to 65 ℃;
programmable logic device controller: the CPLD+DSP processor design is adopted, so that the functions of channel response frequency measurement, channel response frequency compensation, line resistance measurement, hot wire overheat ratio setting, channel synchronization and the like can be completed, and a program downloading and developing interface is reserved.
The heat-ray anemometer suitable for high-speed flow field measurement is used for transonic wind tunnel flow field test, the speed of a test flow field can reach more than Mach number 4, the flow field turbulence degree test precision is improved by more than 20% compared with that of a conventional heat-ray anemometer, and the test time is shortened by 70%.
Claims (3)
1. A hot wire anemometer adapted for high speed flow field measurement, the anemometer comprising: the intelligent hot wire anemometer comprises a sensor comprehensive measurement frame (1-0), a programmable logic control intelligent hot wire anemometer (2-0), a sensor signal wire (3-0), wherein the sensor signal wire (3-0) is communicated with the sensor comprehensive measurement frame (1-0) and the programmable logic control intelligent hot wire anemometer (2-0);
the comprehensive sensor measuring frame (1-0) consists of a hot wire probe (1-1), an acceleration sensor (1-2), a pulse pressure sensor (1-3) and a mounting frame, wherein the hot wire probe (1-1), the acceleration sensor (1-2) and the pulse pressure sensor (1-3) are arranged on the mounting frame;
the programmable logic control intelligent hot wire anemometer (2-0) consists of an acceleration sensor signal conditioning and collecting module (2-1), a hot wire signal conditioning and collecting module (2-2), a programmable logic controller (2-3), a pulse pressure sensor signal conditioning and collecting module (2-4), a lithium battery-based signal excitation and power supply module (2-5), a data storage module (2-6), a communication and expansion control module (2-7), a communication and expansion interface (2-8) and a sensor input signal interface (2-9); the sensor input signal interfaces (2-9) comprise three signal input ends which are respectively connected with the acceleration sensor signal conditioning and collecting module (2-1), the hot wire signal conditioning and collecting module (2-2) and the pulse pressure sensor signal conditioning and collecting module (2-4); the signal output ends of the acceleration sensor signal conditioning and collecting module (2-1), the hot wire signal conditioning and collecting module (2-2) and the pulse pressure sensor signal conditioning and collecting module (2-4) are connected with the programmable logic controller (2-3); the programmable logic controller (2-3) is connected with the data storage module (2-6) and the communication and expansion control module (2-7) through a data line, and is powered by the signal excitation and power supply module (2-5) based on a lithium battery; the communication and expansion control module (2-7) is connected with the communication and expansion interface (2-8).
2. The hot-wire anemometer for high-speed flow field measurement according to claim 1, wherein the programmable logic controller (2-3) is added into the data operation of the hot-wire signal conditioning acquisition module (2-2) by measuring the output signals of the acceleration sensor signal conditioning acquisition module (2-1) and the pulse pressure sensor signal conditioning acquisition module (2-4), so as to improve the measurement precision of wind speed and turbulence, and the method for calculating the wind speed and the turbulence is as follows:
step 1: carrying out frequency spectrum analysis on the output signal of the signal conditioning acquisition module (2-1) of the acceleration sensor to obtain the vibration frequency of the comprehensive sensor measuring frame (1-0);
step 2: according to the vibration frequency of the sensor comprehensive measurement frame (1-0), the output signal of the hot wire signal conditioning and collecting module (2-2) is processed by adopting a decorrelation algorithm, so that the interference signal of the vibration of the sensor comprehensive measurement frame (1-0) caused by a high-speed flow field is reduced;
step 3: the programmable logic controller (2-3) acquires a flow field static pressure pulsation signal near the hot wire probe from the pulsation pressure sensor signal conditioning acquisition module (2-4) and is used for correcting an output signal of the hot wire signal conditioning acquisition module (2-2) so as to improve speed measurement precision, and a wind speed calculation formula is as follows:
wherein E is a hot wire output voltage signal; r is the flow field gas constant; t is the static temperature of the flow field; k is the sensitivity coefficient of the heat ray convection field flow; p is a static pressure value of a flow field near the hot wire probe measured by the pulse pressure sensor signal conditioning acquisition module (2-4);
step 4: the programmable logic controller (2-3) calculates the flow field turbulence Q by measuring the flow pulsation value, static pressure and temperature change of the flow field, and the formula is as follows:
wherein: u is flow field velocity, ρ is flow field density, P is flow field static pressure, T 0 ' is the root mean square deviation of the total temperature pulsation of the flow field,is the flow field total temperature pulsation mean value +.>Is the flow field total temperature pulsation value,/->Is the flow field mass flow pulsation value,/->Is the correlation coefficient of flow field mass flow and total temperature, gamma is the gas specific heat ratio, M is the flow field Mach number.
3. A hot wire anemometer adapted for high speed flow field measurement according to claim 1, wherein in the sensor integrated measuring frame (1-0), a hot wire probe (1-1) is disposed in the middle of the mounting frame, and an acceleration sensor (1-2) and a pulse pressure sensor (1-3) are disposed on both sides of the hot wire probe (1-1), respectively.
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