摘要
本文分析了液压系统气穴起始的一般机理,指出了液压系统气穴现象与水工、造船及水力机械等领域出现的“空化”现象的异同,分析了气穴发生的物理条件及两种扩散形式在气穴形成中的作用,数值计算结果表明,液压系统气穴形成主要取决于液体介质中溶解空气含量,进口压力P_0与气穴部位压力P_c的比值P_0/P_c以及气核与油流相对速度U_r,而与P_0及P_c本身的大小关系不大。
In this paper,cavitation mcchanism in fluid power transmission and control (FPTC) systems is studied.Mathematical description for this kind of cavitation is presented, the differenees between cavitation phenomena in FPTC systems and other systems which work under ambient pressure of o.1 MPa or less are analysed.The diffusive and the conveetive effects of the dissolved gas on cavitation occurence in FPTC systems are examined. Numerical solution is given and the results show that the main facts which influence cavitation inception in FPTC systems are gas content P_O,the pressure ratio λ_p=P_0/P_c and the velocity U_r of the nuclci relative to the main flow.Gas nuclei near solid boundarics in the lower pressure region are the main source for gas bubble occurance,whilc The ones in the main flow are unlikely to become bubbles.
关键词
液压系统
气穴
Cavitation
FPTC system
Cavitation mechanism
Cavitation inception
