Low enthalpy arc heater airflow enthalpy diagnosis system and diagnosis method

Abstract

The invention relates to a low enthalpy arc heater airflow enthalpy diagnosis system and diagnosis method. The method is characterized in that the near-infrared laser absorption spectrum diagnosis technology is utilized to directly measure flow field parameters of the free flow of an arc heater nozzle outlet, based on H2O double-wire temperature measurement, the airflow temperature and the velocity of the free flow of the arc heater nozzle outlet are obtained, in combination with the quantitative relationship among the heat balance airflow enthalpy, the temperature and the pressure, the totallocal airflow enthalpy at the nozzle outlet is obtained. The method is advantaged in that enthalpy measurement precision is improved, the method is applicable to measurement of the airflow enthalpy ofvarious types of low enthalpy arc heaters such as tubular, AC and long section heaters within the enthalpy range of 1500-7500kJ/kg; the method is a non-contact measuring method, interference on the flow field is avoided, the method does not depend on other measurement parameters and machining precision, accurate measurement of the flow field parameters can be realized, and the method can be usedas a powerful complement to enthalpy measurement methods in the prior art.

Description

technical field [0001] The invention relates to a low-enthalpy electric arc heater gas flow enthalpy diagnosis system and a diagnosis method, which belong to the field of aircraft ground aerodynamic heat test research. Background technique [0002] The arc heater is an important test platform to study the aerodynamic thermal protection of the aircraft. It generates high-temperature airflow through arc heating, simulates the enthalpy and heat flow parameters during the reentry process of the aircraft, and conducts ground test research on the thermal protection system. For the aerothermal ground simulation test, one of the keys is to obtain an accurate simulation parameter: the total enthalpy of the airflow. [0003] At present, there are mainly the following methods for measuring the enthalpy value of arc heaters: [0004] 1. Energy balance method. [0005] In this method, the net input power is obtained by subtracting the capacity loss of the cooling water of each componen...

AI Technical Summary

Problems solved by technology

The R.K.Hanson research group at Stanford University has been working on laser absorption spectroscopy combustion diagnosis since the 1970s. In recent years, his research group has used H 2 O Dual-line temperature measurement absorption spectroscopy technology carries out quantitative measurement of airflow temperature, component concentration and velocity in the combustion chamber of scramjet engine. Selecting appropriate spectral lines can realize accurate measurement in the temperature range from normal temperature to 3000K, and the temperature measurement accuracy is lower than 5%

This temperature range covers the static temperature range of the free flow at the exit of the nozzle of the low-enthalpy arc heater. The method currently lacks a direct application of the enthalpy measurement in the ground test of the arc heater, and no specific solution is given

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