Computational Cavitation Flows at Inception and Light Stages on an Axial-Flow Pump Blade and in a Ca

• 作 者: Sumio SAITO MasahiroSHIBATA HideoFUKAE Eisuke OUTA
• 机 构: Tokyo National College of Technology,1220-2 Kunugida-machi,Hachioji-shi,Tokyo 193-0997,Graduate stud
• 出 处: Journal of Thermal Science
• 发表日期: 2007年04期
• 关键词: valve bubble Cage collapse unsteady dispersed captured cavitation Stokes capture

Cavitation flows induced around an axial-flow pump blade and inside a high pressure cage-type valve are simu-lated by a two-dimensional unsteady Navier-Stokes analysis with the simplest treatment of bubble dynamics.Thefluid is assumed as a continuum of homogeneous dispersed mixture of water and vapor nuclei.The analysis isaimed to capture transient stages with high amplitude pressure change during the birth and collapse of the bubbleespecially at the stage of cavitation inception.By the pump blade analysis,in which the field pressure is moderate,cavitation number of the inception and locations of developed cavitation are found to agree with experimental re-suits in a wide flow range between high incidence and negative incidence.In the valve flow analysis,in which thewater pressure of 5MPa is reduced to 2MPa,pressure change responding to the bubble collapse between the vaporpressure lower than 1 KPa and the extreme pressure of higher than 10~4 KPa is captured through a stable computa-tion.Location of the inception bubble and pressure force to the valve plug is found agree well with the respectiveexperimental features.

Cavitation flows induced around an axial-flow pump blade and inside a high pressure cage-type valve are simu-lated by a two-dimensional unsteady Navier-Stokes analysis with the simplest treatment of bubble dynamics. mixture of water and vapor nuclei. the analysis is aimed to capture transient stages with high amplitude pressure change during the birth and collapse of the bubbleespecially at the stage of cavitation inception. By the pump blade analysis, in which the field pressure is moderate, cavitation number of the inception and locations of cavitation are found to agree with experimental re-suits in a wide flow range between high incidence and incidence of negative incidence.In the water flow of 5 MPa is reduced to 2 MPa, pressure change responding to the bubble collapse between the vapor pressure lower than 1 KPa and the extreme pressure of higher than 10 ~ 4 KPa is captured through a stable computa-ti on. Location of the inception bubble and pressure force to the valve plug is found agree well with the respective experimental features.