Calibration method of a cross type hot wire anemometer

A hot-wire anemometer and calibration method technology, applied in the testing/calibration of velocity/acceleration/shock measuring equipment, instruments, velocity/acceleration/shock measurement, etc. problem, to achieve the effect of reducing the number of calibrations

Active Publication Date: 2021-07-13
LOW SPEED AERODYNAMIC INST OF CHINESE AERODYNAMIC RES & DEV CENT
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  • Claims
  • Application Information

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Problems solved by technology

For the calibration of the cross-type hot wire, the angle and speed calibration are often performed at the same time, which will make the calibration process time-consuming
In some cases, the atmospheric pressure and temperature change greatly in a short period of time, such as the flow field measurement of the recirculation wind tunnel without cooling equipment, or the measurement of the turbulent flow field in the icing wind tunnel, the cross-type hot wire The calibration parameters of the

Method used

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  • Calibration method of a cross type hot wire anemometer
  • Calibration method of a cross type hot wire anemometer
  • Calibration method of a cross type hot wire anemometer

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Embodiment 1

[0045] Under standard atmospheric pressure conditions, two calibration data sets were measured when the average ambient temperature was 21°C and 25°C respectively. Among them, when the ambient temperature is 25°C, there are 11 tilt angles (from -30° to 30°, with a step size of 6°) and 30 flow velocity values ​​(from 5m / s to 80m / s) at each angle measuring point. ; When the ambient temperature is 21°C, there are 11 tilt angles and 15 flow velocity values ​​at each angle measuring point.

[0046] The calibration method of the cross type hot wire anemometer comprises the following steps:

[0047] Step 1: Install the cross-type hot wire probe on the adjustable calibrator, and measure the angle θ between the cross-type hot wire probe and the airflow direction;

[0048] Step 2: Use a multimeter to measure the resistance value of the hot wire, probe bracket, and connecting cable, set the superheat ratio of the normal temperature anemometer according to the resistance value, and use t...

Embodiment 2

[0057] In the HRTF high Reynolds number (maximum pressure 238atm) recirculation wind tunnel,.

[0058] The calibration method of the cross type hot wire anemometer comprises the following steps:

[0059] Step 1: Install the cross-type hot wire probe on the adjustable calibrator, and measure the angle θ between the cross-type hot wire probe and the airflow direction;

[0060] Step 2: Use a multimeter to measure the resistance value of the hot wire, probe bracket, and connecting cable, set the superheat ratio of the normal temperature anemometer according to the resistance value, and use the data card to convert the analog output of the normal temperature anemometer into a numerical value;

[0061] Step 3: Set the sampling rate and acquisition time, turn on the calibrator and the normal temperature anemometer, and start data collection; record physical quantities: the voltage output E of the normal temperature anemometer, the wind speed value U of the calibrator ∞ And air tempe...

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Abstract

The invention discloses a method for calibrating a cross-shaped hot-wire anemometer, which includes: measuring the angle θ between the cross-shaped hot-wire probe and the airflow direction; starting data collection; fitting curved surfaces, and calculating the cooling constant k of the cross-shaped hot-wire probe , the calibration constants A, B and n; the effective cooling rate of the cross-type hot wire probe U e calculation steps. It has the advantages of greatly improving the quality of test data and saving test time.

Description

technical field [0001] The invention relates to the field of aerodynamics, in particular to a calibration method for a cross-shaped hot-wire anemometer. Background technique [0002] Due to the high temporal and spatial resolution of hot-wire anemometers, hot-wire anemometers are more suitable for the measurement of turbulent flow fields than particle image velocimetry (PIV) and laser Doppler (LDV). There are three main ways of energy loss in the hot wire: convection, radiation and transfer. Hot wires with an aspect ratio (ratio of length to diameter) greater than 200 dissipate energy primarily by free convection. Since the aspect ratio of most of the hot wires is greater than 200, only the forced convective heat transfer energy loss is considered in the analysis. [0003] The basic principle of the hot wire wind speed measurement method is: heating the micro metal wire through the normal temperature wind speed circuit (CTA), the change of wind speed takes away the heat, a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01P21/02
CPCG01P21/025
Inventor 张军王勋年陈正武张俊龙雷红胜田昊王勇郑谢
Owner LOW SPEED AERODYNAMIC INST OF CHINESE AERODYNAMIC RES & DEV CENT
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