Volume of Fluid Simulation of Borda Mouthpieces

Abstract

The aim of this work is to simulate different length Borda Mouthpieces and to predict the contraction coefficient of the jet for each case. In order to reach this objective initial simulations were carried out of full original experimental device. This preliminary work allowed to isolate the orifice zone without affecting the flow and concentrate computational efforts in orifice zone and capturing free surface appropriately. Volume of Fluid (VOF) Method was used to transport the free surface and sharpness was assured by means of Geo Reconstruct scheme (implemented in Fluent code) and Interface Compression scheme (implemented in OpenFOAM code). Considerations on simulation such as mesh refinement, necessity of turbulence modelling, influence of surface tension and boundary condition setting are discussed. Finally, numerical results from both surface reconstruction schemes are compared with experimental ones and good agreement is found. Additional validation is done against theoretical models found in literature.