幂律流体液膜破裂的线性稳定性分析

为对凝胶推进剂撞击式喷嘴产生的液膜的破裂行为进行研究,使用线性稳定性分析方法并结合幂定律本构方程对幂律流体液膜的稳定性进行了研究,并对流体物性参数、流变参数等对液膜流动稳定性的影响规律进行了分析.结果发现:稠度系数、流动指数和表面张力越大,液膜表面扰动波的增长率越小,波长越大.而较高的液膜速度、气液密度比和液膜厚度都使扰动波增长率变大,但波长随液膜速度和气液密度比的增大而减小,而液膜厚度的情况却相反.理论计算与实验值的对比表明,线性稳定性分析能较准确地预测液膜的破碎长度,但预测的表面波长却大于实验值.

Linear instability analysis of a power-law liquid sheet

In order to investigate the breakup behavior of the liquid sheet formed by gelled propellant impinging injector,a linear instability analysis method and the power-law constitutive equation were used.The effects of the liquid properties and rheological parameters on the stability of liquid sheet were studied.The results show that as the consistency coefficient,flow index and surface tension increase,the surface wave growth rate decreases and the wavelength increases.A larger liquid sheet velocity,gas to liquid density ratio and sheet thickness can accelerate the growth of surface wave.The wavelength decreases with the increase of sheet velocity and gas to liquid density ratio,while the opposite is true for liquid sheet thickness.The comparison between the theoretical and experimental results shows that the linear instability analysis method can predict the breakup length well,but the predicted wavelength is larger than experimental results.