Numerical analysis of the turbulent fluid flow through valves. Geometrical aspects influence at different positiona.

摘要

The aim of this paper is to carry out a group of numerical experiments over Ihe fluid flow through a valve reed, using the CPD&HT code TermoFiuids, an unstructured and parallel object-oriented CPD code for accurate and reliable soiving of industrial flows. Turbulent flow and its solution is a very complex problem due to fere is a non-lineal interaction between viscous and inertial effects further complicated by their rotational nature, together with the three-dimensionality inherent in these types of flow and the non-steady state solutions. In this work, different meshes, geometrical conditions and LES turbulence models (WALE, VMS, QR and SIGMA) are tested and results compared. On the other hand, the fluid flow boundary conditions are obtained by means of the numerical simulation model of hermetic reciprocating compressors tool, NEST-compressor code. The numerical results presented are based on a specific geometry, where the valve gap opening percentage is 11% of hole diameter and Reynolds numbers given by the one-dimensional model is 4.22 x 10s, with density meshes of approximately 8 million CVs. Geometrical aspects related with the orifice's shape and its influence on fluid flow behaviour and pressure drop are analysed in detail, furthermore. low results for different valve openings are also studied.