As low pressure turbine blade rows can operate at fairly low Reynolds numbers, long laminar boundary layers and transitional separation bubbles are not unusual in conventional blade design. Upstream wakes interact with the boundary layer in multistage low pressure turbine applications in a way that can alter the engine performance. In order to provide quick turnaround times, industrial applications involve steady state computations to a large extent which do not accurately model the unsteady wake effects. In this study, a two-stage low pressure turbine is computed at Reynolds numbers between 40,000 and 180,000 using unsteady and steady RANS methods in the flow solver TRACE by DLR and MTU Aero Engines. A quasi-unsteady wake model working together with the Gamma-ReTheta model by Langtry and Menter is applied to the steady state simulation in another step in order to improve the prediction accuracy of low cost simulations utilizing mixing plane interfaces. The steady state results with and without wake model are compared to the time-resolved reference solution and the computation time is evaluated in order to show that the additional model is able to improve steady state mixing plane simulation results without sacrificing the low computational effort provided by the status quo.


Steady State Modeling of Unsteady Wake Induced Transition Effects in a Multistage Low Pressure Turbine

Division / Sponsor:
International Gas Turbine Institute (IGTI)

Paper Proceedings: https://asmedigitalcollection.asme.org/GT/GT2020/volume/84058

Turbo Expo - Virtual Conference

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.