两相脉冲爆震发动机混合流动特性的数值模拟

脉冲爆震发动机具有众多优点,近来受到广泛的关注和研究。要成功起始爆震首先要解决燃油、空气的喷射与混合问题。本文利用CFD程序分别对切向、轴向和径向供气方式的混合室中油、气的混合流动特性进行了三维数值模拟,结果显示三种供气方式各有优劣。切向进气有助于油气的充分混合,但是油、气分布不均,不利于发动机的高频工作;轴向进气时油、气分布比较均匀,但是油气的混合不够充分,增加发动机爆燃向爆震转变的难度;而径向进气的油气分布、混合程度介于切向与轴向进气之间,能耗较大。

Numerical simulation of mixing on two-phase pulse detonation engine

Pulse detonation engine has received much attention of late because of its several advantages compared to existent engines.The fuel-air injection and mixing is one of the most important research issues.This paper addresses the mixing processes for air introduced through tangential inlet,axial inlet and radial inlet.The mixing characteristic inside a mixing chamber is obtained from three-dimensional simulation.The simulation indicates that well mixing but uneven concentration distribution occurs which makes PDE difficult to work in high frequency when air is introduced through the tangential inlet,while bad mixing which makes detonation initiation difficult but well-proportioned distribution occurs when air is introduced through the axial inlet.The mixing degree and gasoline-air distribution performance when air is introduced through the radial inlet are between that of tangential air flow and axial air flow,and the system energy loss is the largest.