椭圆型喷嘴对凝胶推进剂雾化性能影响的理论研究

In order to study the effects of elliptical nozzles on the atomization performance of the gel propellants，the dispersion relation that is the theoretical relationship between the spatial growth rate and the disturbance wave number of the gel propellant elliptical jet were obtained by using the linear stability theory. Because the jet stability plays the key role in the initial atomization，based on this，the effects of various physical factors on the jet stability were discussed，including the eccentricity of the elliptical section，the surface tension coefficient，viscosity，elasticity in non-Newtonian rheological properties，time constant ratio. At the same time，the influence law of elasticity on the special axis conversion phenomenon of elliptical jet was emphatically analysed. Combined with the stability analysis，the law of the effect of various physical factors on the initial atomization of the gel was obtained. It is found that with the increase of surface eccentricity，surface tension and the weakening of viscosity，the growth rate of elliptical jet increases，which is beneficial to improving the initial atomization effect of gel. The non-Newtonian rheological properties of gel propellant have a significant effect on the initial atomization process，especially the effect of elasticity. With the increase of elasticity or the decrease of the time constant ratio，the stability of the elliptical jet is weakened，which makes the jet more likely to break，thereby achieving a good atomization effect. Also，elasticity inhibits jet axis switching.