针栓式喷注器无旋锥形液膜线性不稳定分析

将离心式喷嘴锥形液膜破碎模型应用于针栓式喷注器,对无旋锥形液膜进行了线性不稳定分析。求解色散方程获得了色散关系曲线,分析了无旋锥形液膜表面波发展过程。研究了喷注压降、喷注通道长宽比、液膜半锥角以及正弦模式扰动波加权因子等参数对无旋锥形液膜无量纲破碎时间和破碎长度的影响。结果表明:正弦模式扰动波比曲张模式扰动波增长更快,并且更不稳定。正弦模式扰动波在无旋锥形液膜破碎过程中占优,并且喷注压降越大,液膜破碎的越快。喷注通道长宽比的增加会使得无量纲破碎时间和破碎长度近似线性增大。针栓式喷注器设计时,为利于液膜破碎,喷注通道长宽比应取小值,而液膜半锥角应取大值。

Linear unstable analysis on irrotational conical sheets of pintle injectors

Breakup model of conical sheets of swirl injectors was applied to pintle injectors.In addition,linear unstable analysis on irrotational conical sheets was conducted.The dispersion curves were obtained after solving the dispersion equations.Then,the development process of surface wave of irrotational conical sheets was analyzed.Influences of parameters like injection pressure drop,length-width ratio of injection channel,half cone angles of conical sheets,weighting factor of sinusoidal mode disturbance wave on dimensionless breakup time and breakup length of irrotational conical sheets were studied.Result indicates that the sinusoidal mode disturbance wave develops more quickly and unsteadily than varicose mode disturbance wave.Sinusoidal mode disturbance wave is dominant in the breakup process of irrotational conical sheets.Moreover,the bigger injection pressure drop means the faster conical sheets break.However,dimensionless breakup time and breakup length enlarge linearly along with the increase of length-width ratio of injection channel.To promote breakup process of conical sheets for design of pintle injectors,the small values of the length-width ratio of injection channel should be chosen,while large values of the half cone angles of conical sheets should be chosen.