三维并联式TBCC发动机排气系统设计与实验

为实现三维并联式TBCC排气系统的设计,利用基于二维最大推力理论的密切法设计了圆转矩变截面非对称冲压发动机喷管,并在冲压发动机喷管上壁面为三维曲面的条件下,利用转动加滑动共用面的调节方式实现了涡喷发动机喷管的内型面设计及其喉道面积的调节,从而完成了排气系统设计。随后对设计结果进行了冷流实验验证。结果表明,这种排气系统设计方法具有可行性。在冲压单独工作状态,壁面压力分布的数值计算与实验结果吻合较好,相对方均根偏差低于10.8%；在涡喷单独工作状态及共同工作状态,上壁面压力在激波附面层干扰区域内偏差较大,最大相对偏差可达30.6%。但壁面压力分布的数值计算与实验结果的整体变化趋势一致。 

Design approach and experiment of three-dimensional over/under TBCC exhaust system

To design a three-dimensional turbine based combined cycle (TBCC) exhaust system, a design approach was presented. It employed osculating method based on flowfield of nozzle with optimum thrust to design a three-dimensional section controllable dissymmetric ramjet nozzle. And on the basis of curved ramjet flowpath, a new scheme of rotating and sliding the shared surface was proposed to regulate the throat area of the turbojet nozzle. Cold flow experiments and numerical simulations were conducted at typical test points. The comparison proved that the design approach of TBCC exhaust system is practicable. Under the ramjet mode, the comparison of static pressure distributions showed agreement and the relative root mean square error was less than 10.8%. Under the other modes, obvious deviations appeared in the area where the shock wave interacted with the boundary layer, the maximum relative error was 30.6%. However, the variation tendencies of the static pressure distributions were consistent.