不同含量的固体颗粒对喷嘴内空化流动特殊演化影响的研究

Effects of solid particles with different concentrations on cavitation flow special development in the nozzle

本文研究了不同含量的固体颗粒对喷嘴内空化流动特殊演化的影响。固体颗粒含量从1%变至6%,平均粒径从0.0015 mm增加至0.070 mm。修正适用于清水介质空化流动的Schnerr-Sauer空化模型用于含固体颗粒空化流动的数值模拟。结果表明:含固体颗粒空化流动的含汽量高于清水介质空化流动下的。不同含量的固体颗粒促进空化流动的演化。随着固体颗粒含量的增加,平均粒径的促进范围逐渐变小。研究含固体颗粒空化流动的流动参数与作用于固体颗粒上的力用于揭示机理。最大滑移速度与最小滑移速度的绝对值均高于清水介质空化流动下的。最大与最小湍动能均高于清水介质空化流动下的。含固体颗粒空化流动的混合动能高于清水介质空化流动下的。它们是降低压力促进空化流动发展的主导影响因素。计算所得的萨夫曼升力的量级是10^(−2),对空化流动的影响相对较弱,是次要影响因素。这些因素共同作用,促进喷嘴内含固体颗粒空化流动的特殊发展。

This paper studied effects of solid particles with different concentrations on cavitation flow special evolution in the nozzle.Solid particle concentration varied from 1%to 6%and the mean diameter increased from 0.0015 mm to 0.070 mm.Schnerr-Sauer cavitation model for pure water cavitation flow(PWCF)was modified to perform the numerical simulation of solid particle-water cavitation flow(SPWCF).Results indicated that SPWCF vapor content was greater than that in PWCF.Solid particles with various concentrations promoted cavitation flow evolution.With the increase in concentration,the promotion scope of the mean diameter became smaller gradually.SPWCF flow parameters and force acting on solid particles were discussed to reveal the mechanisms.The maximum and absolute minimum slip velocities were greater than corresponding ones of PWCF.The maximum and minimum turbulent kinetic energies were higher than those of PWCF.SPWCF mixture kinetic energy was higher than that of PWCF.They were primary factors to decrease the pressure to promote cavitation flow evolution.Magnitude of the calculated Saffman lift force was 10^(−2);the effects on cavitation flow evolution were relatively weak;it was the secondary factor.Interactions of these factors promoted the special evolution of SPWCF in the nozzle.