A temperature-humidity-pressure coupled dynamic model for altitude ground test facilities: From component modeling to system validation

As a key parameters of the real high-altitude environment, humidity has a pronounced impact on the performance of aviation equipment and test results. However, current dynamic models for Altitude Ground Test Facilities (AGTF) control research only consider the effects of temperature and pressure, ignoring the influence of humidity.To address this issue, this study takes a critical step beyond existing temperature–pressure models by systematically introducing humidity as a third state variable into the dynamic modeling of AGTFs, establishing a temperature–humidity–pressure coupled modeling framework for the first time. It performs dynamic modeling research on the general components of a typical AGTF, and develops a general underlying component model library that accounts for temperature, humidity, and pressure, which serves as a reusable modeling foundation for subsequent AGTF simulation and control studies. Based on the established model library, a numerical simulation system for a small-scale AGTF is built and validated against actual test data. The results show that the simulated temperature, pressure, and relative humidity in the environmental chamber follow the dynamic trends of the actual test data, with maximum absolute errors of 0.59 K, 288.68 Pa, and 0.44%, respectively. To evaluate the system's suitability for control studies, a Proportional-Integral (PI) controller is employed to conduct closed-loop control analyses of temperature, pressure, and relative humidity on the validated model. The dynamic response curves of the environmental chamber's temperature, pressure, and relative humidity, as produced by the simulation system, demonstrate a high degree of accordance with the prescribed setpoints. During typical dynamic regulation processes, the relative errors for both temperature and pressure are consistently maintained within 1%. Concerning relative humidity, the relative error remains within the 1% threshold for the vast majority of instances; nevertheless, in a few isolated cases, it marginally exceeds this level, although it does not surpass 9%.