CFD Analysis of a Hydraulic Valve
Anu Duttaa, P. Goyalb, R. K. Singhc and A. K. Ghoshd
Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai, India.
aadutta@barc.gov.in
bpgoyal@barc.gov.in
crksingh@barc.gov.in
dccss@barc.gov.in
ABSTRACT
A successful design of high pressure hydraulic valves requires a thorough analysis of both velocity and pressure fields, with the aim of improving the geometry to avoid cavitation. Cavitation behavior prediction of hydraulic valves and its associated performance drop is of high interest for the manufacturers and for the users. The paper presents a CFD analysis of the flow inside a high pressure hydraulic valve. First the analysis was carried out without using cavitation model (single phase). It was observed that absolute pressure was going below the vapor pressure. Hence it was required to turn on the cavitation model. This model enables formation of vapor from liquid when the pressure drops below the vaporization pressure. Since the cavitation bubble grows in a liquid at low temperature the latent heat of evaporation can be neglected and the system can be considered isothermal. Under these conditions the pressure inside the bubble remains practically constant and the growth of the bubble radius can be approximated by the simplified Rayleigh equation. For typical poppet valve geometry, ½ of computational domain is assumed, with velocity inlet and pressure outlet boundary conditions, and a steady flow solution is computed. Because of the highly complex geometry of the hydraulic valve, the computational domain was meshed using unstructured grids using tetrahedral cells only. The paper presents a numerical investigation of the flow inside a hydraulic valve using commercial CFD code CFD-ACE.
Full Text (PDF)
|
