Flow Physics and Control of Three-Dimensional Separation on Swept Wings

Project Sponsor: 
Focus Area: 
Aerodynamics Research
Principal Investigator: 

In the design of aerodynamic vehicles, there must be some care in the design process that would allow the vehicle to move through air or water with the least resistance (smallest amount of drag). As the body can move easier through the flow, the amount of fuel used will be minimized and the carbon footprint can be reduced. 

Under certain conditions, flow separation can occur resulting in an increase in drag and a decrease in aerodynamic performance. Separation occurs as the flow over a body detaches from the surface resulting in eddies and vortices to form and thus an increase in drag. Flow separation is typically three dimensional and due to the level of difficulty has become a growing topic for research in fluid mechanics in the past century. Previous studies focused on flows that are dominated by two dimensional separation with the spanwise velocity component being ignored. Due to this absence, the spanwise influence on the evolution of three dimensional structures is missing resulting in incomplete studies.

2-D flows provide a fundamental understanding of flow separation however are typically not real world scenarios. Real world scenarios involve complex, 3-D flow fields over finite span geometry, which is the focus of my graduate studies. My goals of this study is to clarify and classify unsteady and turbulence origins on swept wing surfaces after which flow control actuators will be used to mitigate separation. If separation can be predicted, it can be prevented by the use of these devices and increase lift, reduce drag and enhance aerodynamic performance. This will be done by analyzing the effect aspect ratio, Reynolds number, sweep angle, and angle of attack has on a NACA 0015 airfoil and analyzing their influence on separation. Eventually this will move to a Stingray UAV and three dimensional separation will be studied and mitigated through various actuators. Experiments will be conducted in RPIs water tunnel and low speed wind tunnel using SPIV, hot wire, dye visualization and electrolysis to map the flow field.