Multidisciplinary Optimization of a High-Speed Low Pressure Turbine using  3D Inverse Design

The design of high-speed low pressure axial turbines, such as those used in aero-engine last stages, is a complex multidisciplinary problem because the higher rotational speed has conflicting effects on the turbine: While it does bring efficiency benefits and a reduced number of stages and hence the turbine weight and the overall dimensions, but it also increases the average isentropic Mach number which could create shock losses and it also leads to high stresses in the last stage rotor blade. Hence, the design of such turbines has to find the right balance between aerodynamic performance and mechanical integrity.

This is why traditional methods often involve multiple iterations between CFD and FEA runs in order to ensure that the appropriate trade-off is achieved, which consumes a lot of computational time and resources. In this webinar, a fast design optimization process focused at suppressing the dominant loss mechanisms but without adversely impacting the blade stress will be demonstrated. Attendees will witness how the inverse design method creates the blade geometry based on specific blade loading parameters and spanwise work distribution requirements. It can explore a large design space with fewer design parameters compared to direct design methods where the blade geometries are parameterized by geometrical variables. 

Loss factors including profile loss, leakage loss, and endwall loss, which are obtained from blade surface velocity velocities, are indicative of the aerodynamic performance and will be minimized during the optimization process. Meanwhile, the centrifugal and bending stresses are related to the blade geometry features. The automated workflow eliminates the need for time-consuming CFD and FEA simulations. CFD and FEA are only employed to validate the outputs generated by the rapid optimization process. The validated results demonstrate enhanced efficiency without any associated increase in stresses.

Who is it for?

The event addresses all engineers, developers or researchers dealing with Turbomachinery Design.