动力效应对民机高速抖振特性影响数值研究

民机的高速抖振通常是由机翼上激波诱导的分离所致,而发动机动力效应可能会对机翼上激波的强度带来明显影响.基于经过TPS标模及DLR-F6标模算例验证的、在多块结构化网格系统上求解雷诺平均N-S方程的数值方法,结合通过定常计算结果判定抖振发生原因及起始升力系数的方法,研究发动机动力效应对某民机巡航构型高速抖振特性的影响.结果表明:动力效应给基于通气短舱设计外形的高速抖振特性带来了不利影响,使其抖振起始升力系数降低约1.3％总升力系数.

Numerical Investigation for the Effects of Power of Engine on Buffet Characteristics of a Civil Aircraft

In the traditional aerodynamic design of aircraft/engine integration, engine system was usually modeled by the flow-through nacelle, but it is very different that the simulation of intake and exhaust effects by flow-through nacelle compared with actual engine work conditions. To improving ability on this problem, the research had be done about the interference of the powered effects to high speed buffet characteristics on the cruise configuration of a civil aircraft with method of solving RANS equations on multi-block structured grid system. Firstly, it was verified that the powered effects can be modeled by intake and exhaust boundary conditions. Secondly, the method that it can be used to judge buffeting onset is given by comprehensive consideration of calculation accuracy and efficiency in the preliminary design stage. Analysis shows: the powered effects had a bad interference to buffeting onset that was designed based on flow-through nacelle at the cruise Mach number, lift coefficient of buffeting onset was reduced about 1.3% of total. We suggest that the effects of power of engine should be considered when checking buffet constrain for the configuration designed based on the flow-through nacelle.