RANS Simulations of a Small Turbine Cascade

Abstract:- Modelling a small turbine is of interest due to the rapid development of small jet engines for model aircraft and UAVs. Because of its size, a small jet engine has small air mass flow rate, low component pressure ratios, high rotational speed and relatively low Reynolds number. The Reynolds number has a major effect on the boundary layer characteristics, shear stresses and losses in the turbine. At low Reynolds number, boundary layers tend to be laminar or in transition and less resistant to separation. Thus, this research is performed to predict separation on the small turbine rotor blade at various Reynolds numbers and turbulence intensity levels. Transitional flows were simulated using the three-equation kT-kL-ω model of Walters and Leylek, which includes the effect of natural transition and bypass transition. The simulation results show separation appears at all flow condition, and thus underline that small turbine rotors are highly susceptible to separation