Flow Control of a Slender Blunt-Nose Body at High Angles of Attack

The flow at high angles of attack over a slender body with a short nose is studied. The effects of nose geometry on the flow and its control using a strake are investigated. Different nose geometries are individually connected to a common cylindrical aftbody to result in three models with an overall length-to diameter ratio of 8.4. Wind-tunnel experiments are conducted at a freestream velocity of 18.5 m/s and angles of attack ranging from -40 to 60 deg to investigate both time-averaged and unsteady behaviors. The results are compared with those from a previous study on models with two of the same nose geometries but overall length-to-diameter ratio of 4. Additionally to the commonly observed average vortex asymmetry, an oscillation of the aftbody vortices is observed even at moderate angles of attack. This oscillation is supposed by just a slight "pointing" of the node. Additionally a seemingly blunt nose can actually behave like a pointed noise. [PUBLICATION ABSTRACT]