摘要
研究了7种不同壅塞管直径和背压对壅塞空化器空化效果的影响。结果表明:不同壅塞管直径的壅塞空化器在背压小于或等于临界压力值时出现壅塞流动现象,此时,壅塞截面上游壅塞管轴心线上的压力、气体体积分数、马赫数都不会受背压影响;当壅塞管中形成混合较均匀的气液两相流时,从壅塞管中段至壅塞截面气液两相流动的马赫数逐渐增加,在压力梯度最高点最大值为0.98;不同壅塞管直径的壅塞空化器要产生强烈的空化都有最佳的背压范围,随着壅塞管直径的增大,最佳的背压范围会逐渐缩小;在壅塞流动的条件下,增大背压或壅塞管直径,最大压力梯度值会增大,壅塞截面会向上游移动。
Under the different back-pressure,seven kinds of choking-cavitator with different choke pipe diameters is simulated by using the computational fluid dynamics software FLUENT,the effects of the choke pipe diameters and the back-pressure on the cavitation strength of the chocking-cavitator are studied. The results showed that the choking flow phenomena will appear in choking-cavitator having sifferent choke pipe diameters when the back-pressure was less than or equal to the value of the critical pressure. It is found that the characteristic parameters,such as pressure,volume fraction of air and Mach number,on the axis of choke pipe in the choked section upstream are not affected by the back pressure. When the homogenous gas-liquid two-phase flow was formed in the choke pipe,it is also found that the Mach number of the gas-liquid two-phase flow increase gradually from the middle section to the choked section of the choke pipe and reach the maximum value of 0. 98,very closed to 1,at the maximum pressure gradient.There exist the best ranges of back-pressure to produce the strong choking cavitation for the choking-cavitator having different diameters of choke pipe. As the choke pipe diameter is increased,the best range of back pressure gradually is reduced. Increasing the choke pipe diameter or back-pressure under the choked flow conditions,the maximum pressure gradient will be also increased and the choked section will move to the choke pipe upstream.
出处
《机械科学与技术》
CSCD
北大核心
2015年第1期131-135,共5页
Mechanical Science and Technology for Aerospace Engineering
基金
湖南省自然科学基金项目(2015JJ5014)资助
关键词
空化
壅塞
壅塞管
背压
壅塞空化器
back-pressure
cavitation
choke
choking-cavitator
computational fluid dynamics
computer simulation
pressure distribution
two phase flow
