Hypersonic Aircraft Infrared Radiation Characteristic Analysis

In recent years, with the rapid development of the hypersonic flight technology, the strategic significance and application value of hypersonic vehicle are even more and more important. Therefore, it is of great significance to do research on infrared radiant properties of flow field around near space hypersonic vehicle for seeking to develop its new and advanced effective infrared stealth technology and successfully developing near space hypersonic vehicle.The radiation source of hypersonic vehicle mainly comes from the aerodynamic heat generated in the high-speed flight.Therefore this thesis firstly analyzes the basic principles and governing equations of aerodynamic heating numerical simulation of hypersonic vehicle from following two aspects:calorically perfect gas and high temperature thermochemical nonequilibrium gas. Besides of this, the article also introduces the method of numerical simulation and generative process of block structured grid.In this thesis, I adopt the supposition that the flow field and the radiation field are decoupled. In other words, The influence of the heat radiation can be neglected while calculating numerically flow field; and then uses the known parameters of flow field to calculate radiant parameters and radiant intensity field.The article briefly describes the basic concepts and theorems of infrared radiation, as well as elaborate the radiation transport equation and radiation energy equation in the radiation, and then calculate the temperature field in the fluid dynamics coupled with aerodynamic heat skinning radiation; Finally, complexs background, including the direct irradiance of sun and the target reflection of infrared radiation, influence on infrared radiation.In addition, this thesis also introduces the detailed principle of the air radiant properties and atmospheric transmittance. In the part of air radiant material parameters calculation, Line-by-line method has been adopted for calculating the radiant absorption coefficient of gas; line parameters required is obtained from American HITRAN database. Then, numerical simulation has been done for3-5um band infrared radiant properties of the model that has been previously constructed; Theory and numerical methods of high-resolution atmospheric transmittance are introduced lastly.The present work has laid a foundation for the further deepening of the infrared radiation characteristics of hypersonic vehicles and infrared stealth characteristics.