Nature has produced resourceful structures that are efficient and multipurpose in order to survive in complex environment. One inspiration for drag reduction design comes from the efficient movement of sharks that are shaped like microscope riblets aligned along the streamwise direction. In this paper, the compressor cascade flow in conjunction with sharkskin-inspired U-shape riblets at the Reynold number of 410,000 are simulated by using large eddy simulation (LES) method. The fine-scale structured mesh inside riblet valley are generated and the wall adapted local eddy (WALE) viscosity model is adopted here. The flow control mechanisms of riblets is firstly studied according to the relative changes of flow drags, transition positions, vortex formations and turbulence fluctuations of boundary layer flows when compared to the smooth compressor cascade. The optimal riblet design is then obtained with modifying the geometric parameters and a simplified criterion for compressor riblet design is proposed in the end. The post-processing outcomes show that the turbulent vortices mainly remain above the riblets and only interact within the tip zone. The low-speed streak inside the riblet valleys produces low shear stress and the high-shear stresses occur at the riblet tip, finally resulting in the drag reduction. Here, the total pressure loss coefficient can be reduced by a maximum of 10% when compared to the smooth compressor cascade, which shows the sharkskin inspired riblet surface is a promising flow control technique in reducing the compressor blade profile losses.


Physical Mechanisms Investigation of Sharkskin-Inspired Compressor Cascade Based on Large Eddy Simulations

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.