Enhancing Diffuser Performance Through Wing Vortex Generators: Part II –Experimental and Numerical Study

An empirical and numerical study was conducted to investigate the flow characteristics in a diffuser fitted with different arrangements of Wing Vortex Generators (WVGs), including Delta Wing Vortex Generators (DWVGs) and Rectangular Wing Vortex Generators (RWVGs). The flow at the diffuser inlet was uniform, and its development was analyzed. The WVGs were positioned near the inlet. The Reynolds number (Re), calculated based on the diffuser length and inlet velocity, ranged from ۱۷,۰۰۰ to ۴۳,۰۰۰. The loss coefficient (K) decreases as Re increases in the smooth diffuser and declines further in roughened cases, primarily due to reduced flow separation. By mitigating flow separation and enhancing pressure recovery (CP is defined as the ratio of the pressure increase to the dynamic pressure at the diffuser throat), the WVGs improve the pressure coefficient (CP) compared to the smooth case. The increase in CP is more pronounced for RWVGs than DWVGs in all tested configurations, indicating that RWVGs are more effective at controlling flow separation. Additionally, three RWVG pairs produce a higher skin friction factor (Cf) than other configurations.

Keywords:

Cf (Skin Friction Factor) , CP (Pressure recovery) , Diffuser loss coefficient (K) , DWVGs (Delta Winglet Vortex Generators) , RWVGs (Rectangular Winglet Vortex Generators) , WVGs (Winglet Vortex Generators)