Inventions, Vol. 9, page 28: Effect of perforated plate on impact structure changes of NACA0012 airfoil
Inventionsdoi:10.3390/inventions9020028
Authors: Mihnea Gall Oana Dumitrescu Valeriu Drăgan Daniel Eugeniu Crunşeanu
This study investigates a passive flow control technique to mitigate the adverse effects of shock wave and boundary layer interactions on the NACA 0012 airfoil. A perforated plate with strategically positioned cavities below the shock wave anchoring points is used. Airfoils with perforated plates of different orifice sizes (ranging from 0.5 to 1.2 mm) were constructed using various manufacturing techniques. Experimental analysis utilizes an “Eiffel” type open wind tunnel and a Z-type Schlieren system for flow visualization and static pressure measurements obtained from the bottom wall. Empirical observations are compared with stable 3D density-based numerical simulations performed in Ansys FLUENT for comprehensive analysis and validation. The implementation of the perforated plate caused a significant change in the shock structure, transforming it from a strong normal shock to a large lambda shock. The total pressure loss increased by 0.2% in the passive control case, which is attributed to the ability of the perforated plates to weaken the intensity of the shock wave anchored above. The perforated plate caused significant fluctuations in shear stress, with lower stresses observed in the plate region due to flow separation of the cavity blow. Balancing shock and viscous losses proves critical to obtaining good results with this passive flow control method.