The high-temperature gas soft measurement method based on the temperature attenuation patterns of flowing argon gas inside a cavity

Abstract The device for generating the airflow temperature signal is employed in aircraft ground simulation. This process involves heating the argon gas by the arc discharge to generate high-temperature gas, which subsequently flows into the cavity and mixes with cold gas to produce the temperature signal. However, the temperature of argon gas at the entrance of the cavity is excessively high, and sensor installation is challenging, making direct measurement difficult. This paper introduces a high-temperature gas soft measurement method (HTGSM) based on the temperature attenuation patterns of flowing argon gas inside the cavity, and establishes a mathematical model for the flow and temperature distribution of argon gas within the cavity. The method calculates the target temperature at the entrance of the cavity by measuring the lower-temperature argon gas at the outlet of the cavity. Furthermore, a simulation and experimental platform were set up to validate the proposed method. The experimental results indicate that there is an 7.9% deviation between the soft measurement values and the directly measured values of argon gas temperature in the middle of the cavity. At the outlet of the cavity, the maximum deviation between the directly measured argon gas temperature and the simulation calculation results based on the soft measurement values at the entrance temperature is 5.2%. The paper rigorously validates the accuracy of the soft measurement method from various perspectives. Notably, this method offers the advantage of remote indirect measurement, and indirectly expanding the upper limit of the temperature sensor.