基于压敏漆的多羽流气动力效应试验研究

多股羽流相互作用会形成复杂流场形态的干扰羽流，为了对干扰羽流开展气动力效应试验研究，采用压敏漆（PSP）表面压力光学测量技术，对以常温空气为工质的单喷嘴羽流和双喷嘴干扰羽流撞击平板模型的气动力进行了高分辨率的全场测量，分析了喷嘴和平板间不同入射距离和入射角对羽流气动力作用强度和范围的影响。试验结果表明，以高透氧聚合物为基层的压敏漆在羽流气动力测量中具有快速响应的特性，能分辨Pa级的微小压力变化。相对传统离散测压孔方法，压敏漆温度敏感度低，能捕捉大梯度的压力变化，准确描述羽流气动力效应。通过对比，发现干扰羽流对气动力具有明显增强作用，且增强作用随着入射距离的降低而减弱，干扰羽流的气动力不能直接用单股羽流的气动力进行线性叠加；羽流相互作用增强羽流返流，在航天器设计中需要考虑多股羽流相互作用后的羽流防护问题。 

Experimental research on aerodynamic force effect of multiple plumes based on pressure-sensitive paint technique

The interaction of multiple plumes may cause interacted plumes with complex flow field. To experimentally study the aerodynamic force effects of interacted plumes, an optical measurement technique for surface pressure based on Pressure-Sensitive Paint (PSP) was employed to globally measure the aerodynamic force of a plate model impinged by single-and dual-nozzle plumes which used normal-temperature air as the working gas with high resolution. The strength and region of the aerodynamic force under different distances and angles between the nozzles and the plate were analyzed. The experimental results show that PSP using poly(TMSP) as the binder and PtTFPP as the luminophore exhibits fast response and can distinguish tiny pressure variation of Pa level in the plume aerodynamic force measurement. Compared to the conventional method based on discrete pressure taps, PSP is low temperature-dependent, is capable of measuring large pressure gradient, and can accurately describe the aerodynamic force effect of plume. It is found that the aerodynamic force is significantly enhanced by the interacted plumes, and the enhancement effect decreases as the incident distance reduces. The aerodynamic force of the interacted plumes cannot be directly superimposed by those of single plumes linearly. Plume interaction enhances the backflow intensity, and thus the plume shield after multi-plume interaction should be taken into account in spacecraft design.