CFD Analysis of a Void Distribution Benchmark of the NUPEC PSBT Tests : Model Calibration and Influence of Turbulence Modelling

Abstract EN

The paper presents CFD calculations of the void distribution tests of the PSBT benchmark using ANSYS CFX-12.1.

First, relevant aspects of the implemented wall boiling model are reviewed highlighting the uncertainties in several model parameters.

It is then shown that the measured cross-sectionally averaged values can be reproduced well with a single set of calibrated model parameters for different test cases.

For the reproduction of patterns of void distribution cross-sections, attention has to be focussed on the modelling of turbulence in the narrow channel.

Only a turbulence model with the capability to resolve turbulent secondary flows is able to reproduce at least qualitatively the observed void distribution patterns.