飞机加改装部件绕流脉动压力研究

RESEARCH ON THE FLUCTUATING PRESSURE OF THE FLOW AROUND THE AIRCRAFT COMPONENT UNDER MODIFICATION

现役飞机的加改装或改型 ,是赋予装备新功能、提高装备性能和综合战斗力的一条快速、有效的途径。在加改装工程中 ,防止发生加改装部件的结构振动是一个较为突出的技术难点 ,而导致飞机部件结构振动的主要激励源之一是其绕流产生的非定常气动载荷。描述了飞机加改装部件绕流的典型流态及其脉动压力的主要特点 ,提出了加改装部件外形的综合优化设计方法 。

Modification of active aircraft is an effective and quick approach to endow it with new functions or to raise its performance and fighting capacity. Preventing the structural vibration of the component under modification is a rather difficult technological point. One of the chief arousing sources of the vibration of the component under modification is the fluctuating pressure of the component flow. This paper describes the features of the component flow and its fluctuating pressure, provides an optimum modification design method for the external shape of the component, and presents the main result of a study on the correlation of the wind tunnel experiment and the flight test for the fluctuating pressure of the component flow. The fluctuating pressure in the strong separated flow area behind the bluff component under modification is very high, and the data correlation of wind tunnel experiments with flight tests is highly good. The fluctuating pressure caused by the shock wave at the shoulder of the component under modification is relatively high, and the data correlation of wind tunnel experiments with flight tests is fairly good, and highly good at the low frequency band. On the contrary, the fluctuating pressure in the attached flow area is very low, and the data correlation of wind tunnel experiments with flight tests is poor due to the output signals of wind tunnel experiments concealed by the wind tunnel background noise.