Investigating unsteady secondary flows in a linear low pressure turbine cascade: A combined experimental and numerical study

Authors

R. Ciorciari - Institute of Jet Propulsion, Universität der Bundeswehr München, Germany
I. Kirik - Institute of Jet Propulsion, Universität der Bundeswehr München, Germany
R. Niehuis - Institute of Jet Propulsion, Universität der Bundeswehr München, Germany

Abstract

The effects of unsteady incoming wakes on the secondary flow in a linear low pressure turbine cascade, named T106, were investigated by experiments in a high speed cascade wind tunnel and by U-RANS simulations. In this paper, results of a variety of cases with different Strouhal numbers and flow coefficients were compared and the differences analysed. The upstream incoming wakes in the experiment were generated by a wake generator and were considered in the CFD simulations likewise. The computations have been conducted using the flow solver TRACE. Time-averaged and time-accurate ensemble averaged experimental data permit the evaluation of the numerical U-RANS predictions for some of the investigated con- figurations. 3D CTA hot-wire traverses downstream the cascade permit to analyse the velocity and the turbulent flow field for the investigated configurations. Results of a newly implemented fast response total pressure probe allow to compare the relative unsteady ensemble averaged fluctuations to the CFD results downstream of the cascade.