Department Seminar of Ofek Drori - SIMULTANEOUS DESIGN OF FLOW CONTROL AND SHAPE WITH EXPERIMENTAL VALIDATION
School of Mechanical Engineering Seminar
Wednesday, December 20, 2021 at 14:00
Wolfson Building of Mechanical Engineering, Room 206
Simultaneous design of flow control and shape with experimental validation
MSc student of Prof. Avraham (“Avi”) Seifert
A numerical and experimental study on simultaneous design of active flow control and geometry was conducted. The desire of creating large aerodynamic shapes with large volume (for carrying people, fuel, etc.) is always in contrast with the aerodynamic performances, especially with drag force. This study is the first milestone in a research focuses on the optimization of body geometry and active flow control (AFC). An axisymmetric model was design and AFC system (combining steady suction and steady blowing) was installed in it. The model geometry was parametrically defined so the defined flow conditions led to separated flow that can be reattached using the designed AFC system. Different geometries were first analyzed using CFD simulations and then flow control boundary conditions were applied. The results obtained from the CFD simulations were the platform for the Meadow laboratory low speed low turbulence (LSLT) wind tunnel tests (WTT).
The CFD simulations identified the critical angle (that characteristic the model geometry) that led to flow separation. In addition, after analyzing different suction location (as well as combinations of suction locations), the optimal location for applying suction was obtained. The CFD results were followed by WTT examined the effect of suction technic (slot or holes) and its results were compared with the CFD prediction.
Both CFD and WTT results were compared with and without flow control. In the baseline results, where no AFC was applied, differences in drag and pressure coefficients were observed due to phenomenon took place only at the WTT. While the AFC was operated in selected configurations, both methods showed drag reduction with similar trends, but even in this case different values were obtained.
The encouraging results and conclusions of this study constitutes as a platform for continues work on body geometry alongside flow control optimization and hopefully affect the design of future aerodynamic vehicles.