武装直升机机体红外辐射数值模拟方法研究

Study on Numerical Simulation Method of Infrared Radiation Calculating for Military Helicopter Body

针对武装直升机机体红外辐射的数值计算问题,本文首先在分析蒙皮受热情况的基础上,提出了一种利用区域分解求解机体表面温度分布的方法.该方法将机体分为3个温度区域:一般蒙皮区域,其温度变化通过热网络法求解;发动机热影响蒙皮区域,其温度变化由热源法求解;喷焰加热蒙皮区域,其温度变化由直升机旋翼洗流干扰下的热喷流模拟求解.在此基础上,研究了机体红外辐射的数值模拟方法,包括蒙皮自身辐射的计算和蒙皮反射辐射的计算.最后,应用本文方法,对某型武装直升机的机体红外辐射强度进行了数值模拟,计算结果符合实际分布规律,计算误差在工程精度要求内.该方法已应用于武装直升机红外辐射数值模拟软件中,应用表明该方法稳定、可靠,适于工程分析.

To solve the problem of calculating military helicopter body＇ s infrared radiation, a new algorithm based on using domain decomposition method to calculate helicopter body＇ s temperature distribution was proposed. Based on analyzing the heating situation of helicopter skin, the body was divided into three temperature domains, ordinary area whose temperature caused by environment, engine influence area whose temperature caused by engine heating and engine jet influence area whose temperature caused by engine＇ s hot jet under the interference effect of rotor downwash. The thermal network method was introduced to calculate the temperature distribution of ordinary helicopter skin area. The temperature field of engine influence skin domain was computed by using heat-source method. Through the simulation of engine jet in rotor downwash flow, the temperature of engine jet influence skin area was calculated. Synthesis the three kinds of temperature, the whole temperature distribution of helicopter＇s body was gained. Then, based on this, the numerical simulation technology of infrared radiation for helicopter body was researched, including the skin＇ s self-radiation and the skin＇ s reflective radiation. The calculation results of certain military helicopter show that the percentage error can meet the engineering requirement and the data comply with the practical distribution rule. The algorithm has been used successfully in the numerical simulation software of military helicopter＇ s infrared radiation. Applications show that the algorithm is stable, reliable and suitable for engineering analyses