Validation of numerical computations and turbulence models combinations for gas turbine cascade blade flow

الملخص EN

The accuracy of computer codes for turbo-machinery turbulent flow field calculations relies strongly on the type and behavior of the turbulence model used in the computations.

Analysis of different Reynolds Average Navier-Stokes Equation (RANS) based turbulence models was applied to predict the flow field in the linear first stage gas turbine cascade blade.

The experimental investigation is also introduced to validate the accuracy of turbulence models.

This was done by using five linear cascade blades tested in an open jet type low-speed subsonic wind tunnel.

The static pressure distribution was measured at the midspan of cascade middle blade by using static pressure taps.

The numerical results obtained from different turbulence model simulations is individually reviewed for the correctness of its predictions and compared with the experimental data in terms of integrated flow parameters, such as static pressure coefficient distribution on both blade sides.

The results show that RNG k-e turbulence model gave the best prediction of pressure distribution when compared with the experimental data.

Prediction of standard k-ε and k-ω turbulence models fail to predict accurately the flow field parameters in cascade passage.

Prediction of (k-ε) turbulence model overestimate the turbulence kinetic energy values, especially in the regions of high velocity at blade suction side, also not accurately predict the flow separation on the blade suction side.