Development of Inlet Boundary Condition for Accurate Multi-Jet Simulations

ABSTRACT To ensure that a high degree of confidence can be assigned to the ongoing multi-jet impingement simulations, a single axisymmetric jet was first numerically resolved and compared to in-house jet experiments. This required the definition of the inlet boundary condition of the jet to be accurately documented. To that end, a turbulent flow exiting a long circular pipe was first modelled and analyzed to ensure that the inlet boundary condition to a single axisymmetric jet was in good agreement with the experiments. Initially, analysis was performed to approximate the length necessary to generate a fully developed pipe flow. Once, the development length based on mean velocity was obtained, the pipe flow at a Reynolds number of 7,500 was analyzed and compared with in house experimental data, and also with DNS and experimental data from Eggels [1]. It was observed that the solution using the SST turbulence model performs better than the solution obtained using the Realizable k-ε model in the pipe domain. Once the analysis was completed, velocity and turbulence components at the outlet of the pipe were extracted and used as input for the jet flow simulations.