旋翼洗流影响直升机红外辐射的计算分析  

Calculation Analysis of Rotor Downwash Influence on Infrared Radiation of Helicopter

作　　者：陈海涛[1] 卞恩荣[2] 廖文和[1] 

机构地区：[1]南京航空航天大学机电学院,南京210016 [2]南京航空航天大学航空宇航学院,南京210016

出　　处：《南京航空航天大学学报》2008年第5期600-604,共5页Journal of Nanjing University of Aeronautics & Astronautics

摘　　要：针对在旋翼洗流作用下,高速、高温的发动机喷流对直升机的红外辐射特性有着相当大影响的问题,提出了一种计算分析方法。该方法首先利用自由尾流技术对旋翼下洗流场进行计算;在此基础上,将旋翼洗流视为一种横流干扰,以计算得出的洗流速度为边界条件,进行了发动机热喷流模拟;然后,计算了喷流截面的温度涡线分布,并以此确定了旋翼洗流影响下的机体温度分布;最后,计算和分析了旋翼洗流对直升机红外辐射强度的影响。对某型直升机计算分析表明,该方法稳定可靠,结果符合实际情况,适于工程分析和预估。该方法还可用于直升机机体温度场的工程求解。Under the effects of rotor downwash,the high-speed and high-temperature engine jet will cause a considerable change of infrared radiation characterstics of the helicopter. To research the problem,an analytical method based on the simulation of engine jet in rotor downwash flow is proposed to predict the influence. Firstly,the free wake is analyzed to calculate the rotor downwash around the engine jet space. Regarding the rotor downwash flow as an interference cross-flow,the engine jet flow field is simulated by using the calculated downwash velocity as a bounty condition. After calculating the temperature vortex filament distribution of jet cross section,the temperature field of the helicopter under the effects of the rotor downwash is obtained. Finally,the rotor downwash influence on infrared intensity of the hedicopter is calculated and analyzed. The application of a certain helicopter shows that the calculation results are in agreement with the practical situation. And the method is proved to be stable, reliable and suitable for engineering analyses and prediction. Furthermore ,the method can be used as an engineering algorithm to calculate the temperature field of the helicopter.

关 键 词：直升机 红外辐射 旋翼 下洗流 自由尾流 喷流 

分 类 号：V218[航空宇航科学与技术—航空宇航推进理论与工程]