Research on Infrared Radiation Signatures of High-altitude Plume based on DSMC method

摘要

Exhaust plume flow field have the characteristics of high temperature, high speed and multi-species flow. Exhaust plume infrared signal are important basis of diagnosing, detecting and identifying plume spectrum. This paper focuses on the infrared radiation characteristics of high-altitude plume. The plume flows exhausted from a micro-nozzle of a low-thrust engine at high-altitude have been simulated numerically through using a DSMC method. Both the properties of plume flow at high altitude and the non-equilibrium effect related to rarefied gases are analyzed. Results are given numerically in good agreement with high-altitude plume observations. With the fields of pressure, temperature and main components of the exhaust plume as input data, the line-by-line method was used to calculate the 2?5m infrared spectral radiation properties of the plume. Different flight conditions are considered to analyze the influence on the infrared radiation characteristics. Some interesting conclusion are finally achieved.