同轴式气-气喷注器混合场影响因素流动显示研究

为了深入理解同轴气-气喷注器气流混合机理,利用粒子图像测速仪(PIV)系统对同轴直流式和同轴离心式气-气喷注器开展了流动显示实验,研究了喷注器关键设计参数对气流混合扩散过程的影响规律.实验结果表明:对于同轴直流式喷注器,氧/氢动量比决定着气流接触面上卷吸作用的大小,动量比越大,卷吸作用越强,混合效果越好;对于同轴离心式喷注器,气流的旋度控制着气流的混合过程,旋度越大,混合效果越好.可以通过减小外环喷注压降或者给中心喷孔一定的缩进距离来增大旋度,增强旋流作用,加强气流的混合.

Research on flow visualization of coaxial gas-gas injector mixing flowfield

To pursue the proper design criteria for gas-gas injector,the flow visualization technology with particle image velocimetry(PIV) system was adopted to investigate the mixing mechanism.The coaxial shear and swirl configurations were selected.The results show that the momentum ratio of oxygen to hydrogen prevails in the mixing process of coaxial shear injector,while the swirl numbers dominate the mixing part of coaxial swirl injector.Good mixing was gained at high momentum ratio and high swirl numbers.For the designer,the combination of high annular pressure drop and low center pressure drop is recommended for the coaxial shear injector,and the combination of low annular pressure drop and proper recess length of center post recommended for swirl injector.