Ground effects on separated laminar flows past an

Authors: Zhen Li Chuanjin Lan Laibing Jia Yanbao Ma

Publish Date: 2016/10/17

Volume: 31, Issue: 2, Pages: 127-136

PDF Link

Abstract

The appearance of a ground surface can play an important role in the flow structures for the flows past a flat plate We conduct twodimensional numerical simulations on viscous flows past a flat plate inclined at an angle of attack of 20circ with ground effects using a finitevolume method Results show that the effects on the separated flow from the ground are highly dependent on the gap G between the plate and the ground As the gap decreases the strength of vortices generated from the trailing edge is restrained which is consistent with experimental observations Further decrease in the gap even eliminates the vortex shedding and yields a steady flow It is also found that the flow between the gap can either be accelerated at large gap ratios G/L 1 G is the gap L is the plate length or be decelerated at small gap ratios G/L 1 Furthermore the numerical results show that the wake flow behind the plate can significantly change the distribution of surface shear stress on the ground Specifically the mean shear stress on the ground in the downstream region at a gap ratio G/L = 20 is one order of magnitude larger than that at a small gap ratio G/L = 03 and the length of the downstream region where the shear stress can be effectively changed is much larger than the plate length which provides a guideline to manipulate the ground wall surface shear stress using an inclined plate in the vicinity of the wall

Keywords: