Numerical Prediction of Flow Patterns after Various Pipe Fittings

Abstract: An accurate prediction of flows using CFD depends on a large number of factors. In addition to discretizing the flow region, the correct definition of boundary or initial conditions and the choice of suitable numerical methods, the applied turbulence model influences the results of the flow simulation to a great extent. Therefore, a validation of the results with the experimental data is of great importance for a correct selection of a turbulence model. It is the scope of this paper to assess different turbulence models for the simulation of pipe flows. The calculation results of pipe flows through a combination of 90° elbows and a 1/3 segmental orifice are compared with experimental measurement results. This has the advantage that the suitability of the turbulence models for simulating both shear and swirl flows can be investigated. Thus, the k-ω, k-ε model and the Launder Reece Rodi Reynolds stress model are compared with each other and experimental results. Furthermore, this investigation is extended through including a much more c detached-eddy simulation. This model provides better prediction of the flow by resolving the large eddies and modeling the small ones. The experimental results originate from LDV measurements over the entire pipe cross-section. This measuring method provides velocity vectors over the measured surface