High precision of CFD code was used to study supercritical Airfoil RAE2822 superimposed with different shock control bumps under the transonic conditions.A successful improvement was made to current widely used Hicks-...High precision of CFD code was used to study supercritical Airfoil RAE2822 superimposed with different shock control bumps under the transonic conditions.A successful improvement was made to current widely used Hicks-Henne functions which describe shock control bumps.Based on improving the airfoil's lift-drag ratio,the study shows that,(1) the best bump crest position is at the position close to 50% of bump chord,which is almost independent of free stream or pre-shock Mach numbers,but the bump height is highly coupled with the crest position,which means that the higher the bump is,the more obviously the crest position affects the airfoil lift-drag ratio,and it becomes more evident with the increase of free stream or pre-shock Mach numbers;(2) in case that the lift-drag ratio of airfoil with bump is higher than basic airfoil,almost all the optimum distances between bump crest and shock wave are close to 30% of bump chord;(3) almost all the lift-drag ratios of airfoil with bump increase as bump chord length increases,of which this trend becomes more evident as bump height increases;(4) with the increase of the bump height,almost all the lift-drag ratios of airfoil with bump decrease at low free stream or pre-shock Mach numbers.When the Mach numbers are higher,the lift-drag ratio of airfoil increases as the increase of the bump height,and particularly,the trend tends to be visible when the Mach numbers are at a high level.展开更多
文摘High precision of CFD code was used to study supercritical Airfoil RAE2822 superimposed with different shock control bumps under the transonic conditions.A successful improvement was made to current widely used Hicks-Henne functions which describe shock control bumps.Based on improving the airfoil's lift-drag ratio,the study shows that,(1) the best bump crest position is at the position close to 50% of bump chord,which is almost independent of free stream or pre-shock Mach numbers,but the bump height is highly coupled with the crest position,which means that the higher the bump is,the more obviously the crest position affects the airfoil lift-drag ratio,and it becomes more evident with the increase of free stream or pre-shock Mach numbers;(2) in case that the lift-drag ratio of airfoil with bump is higher than basic airfoil,almost all the optimum distances between bump crest and shock wave are close to 30% of bump chord;(3) almost all the lift-drag ratios of airfoil with bump increase as bump chord length increases,of which this trend becomes more evident as bump height increases;(4) with the increase of the bump height,almost all the lift-drag ratios of airfoil with bump decrease at low free stream or pre-shock Mach numbers.When the Mach numbers are higher,the lift-drag ratio of airfoil increases as the increase of the bump height,and particularly,the trend tends to be visible when the Mach numbers are at a high level.
