Abstract
This paper presents a 3D Co-Flow Jet (CFJ) active flow control airfoil with an integrated micro-compressor at high angles of attack for takeoff and landing conditions. A micro-compressor designed by our team is used as the fluidic actuator for CFJ active flow control (AFC). The simulations are performed at freestream Mach number 0.07 and angles of attack (AoA) from 20 degrees to 70 degrees to mimic takeoff and landing conditions. The RPM of the embedded micro-compressor is controlled to achieve a variety of operating conditions to satisfy the different AoA conditions. The micro-compressor actuator is designed for high efficiency at a required mass flow rate in order for the CFJ airfoil to maintain a desired momentum coefficient (C-mu). The aerodynamic performance, CFJ mass flow rate, energy expenditure, and 3D flow field are studied for the CFJ airfoil by varying the micro-compressor RPM and the CFJ airfoil AoA. The results show that airfoil separation can occur due to the mismatch of the micro-compressor and the airfoil flow conditions. At AoA of 20 degrees, the compressor at higher power level with 30,000 RPM stalls both the flow of the micro-compressor and airfoil. By reducing the RPM to 20,000, the CFJ airfoil flow is nicely attached with the lift coefficient doubled and the aerodynamic efficiency (C-L/C-D) c increased by 343%. With the AoA varying from 20 degrees to 70 degrees, increasing the RPM of the micro-compressor actuator as well as the power is necessary to overcome the extreme adverse pressure gradient to maintain attached flow with lift coefficient increasing from 3.2 to 13.7. The priority of this study is to demonstrate the functionality of the integrated CFJ airfoil system at high lift and high AoA. The efficiency is only optimized for AoA of 20 degrees. For all the AoAs of 30 degrees and higher, a large C mu is used to save simulation time, without iterations to minimize the CFJ power. The aerodynamic performance of the CFJ airfoil shows a positive C-L/C-D of 111.7 and high negative values due to the generation of negative drag, which is thrust. A corrected aerodynamic efficiency (C-L/C-D) (c) of 13.3 is obtained for the case of AoA = 20 degrees at compressor RPM 20,000 where the micro-compressor efficiency (.) is 78.2%. The highest micro-compressor efficiency obtained is 80.2% at AoA of 40 degrees and RPM 45,000. A high lift coefficient (C-L) of 13.7 is obtained at AoA = 70 degrees at compressor RPM 75,000 where. is 72% due to significant deviation from the design RPM of 30,000. This study indicates that the CFJ airfoil can be used for high lift coefficient with high compressor efficiency. The micro-compressor actuator designed has a wide operating range with high efficiency. This study is a virtual simulation of the integrated system of the CFJ airfoil and the micro-compressor actuator to demonstrate that the CFJ airfoil can be controlled at takeoff and landing conditions for ultra-high lift coefficient and AoA.