保形通道式扩压器在微型涡喷发动机中的应用

Application of Consecutive Passage Diffuser in Micro-turbojet Engine

采用结构新颖的保形通道式扩压器并运用其三维设计方法,对某直径16 cm的微型涡轮发动机的扩压器进行改进设计。改进型微型扩压器由完整的主叶片和布置于通道后部的分流叶片构成,相较于原型的径向、轴向分段叶片式扩压器,可全程对气流的扩压度和流向进行控制,避免气流在无叶转弯段的强烈掺混,减小流动损失。数值模拟结果表明,在设计工况下,改进前后扩压器的流量特性基本保持一致,改进型微型扩压器总压恢复系数提高5.5%,扩压能力亦有明显增强。

A new conceptual consecutive passage diffuser is adopted in the redesign of the diffuser in a 16 cm-diameter micro-turbojet engine.The new-style micro-diffuser composed of the full blades and splitters in the passage rear can control the divergence angle and the turning angle of the flow from the inlet to the exit.Meanwhile,it can avoid the dumping flow into an annular turning bend with significant mixing and reduce Mach number losses.Numerical simulation shows that the flow characteristics of the diffuser are basically consistent before and after improved under the design condition.The total pressure recovery coefficient of the micro-diffuser is improved by 5.5% and its diffusion capacity is enhanced.