Wind Tunnel Investigation of Grid Finned Missile Configuration over Planar Control Surfaces

Abstract

The present work deals with the investigation of aerodynamic forces on grid finned missile configuration over the conventional planar fins. The work is done in this area to provide some further insight reasons why the use of grid fins would be advantageous over more conventional control surfaces. Grid fins usually produce much higher lifting forces and pitching moments to overcome the drag they create. The work involves experimental analysis using wind tunnel testing and comparing the results for both the fin configuration. The dimensions of the missile body configurations are same with only the fin configurations being different. This allows for one – to –one comparison of the data to isolate the effects of fin geometry. The experimental work has been performed using the low speed wind tunnel of Department of Aerospace Engineering, MIT-AU. The tunnel is having a rectangular test section of 3ft height, 4ft width and 6 ft length. The models have been tested in the Reynolds number range of Re = 4.79 x 10 5 to 1.3 x 10 6 for different angle of attack ranging from –15 to +15. Free stream pressure of the test section is 1 bar and the blockage area was kept less than 5%. The force measurements were taken using a six-component internal strain gauge balance associated with a 20-channel data acquisition system (VISHAY 5100 B Scanner). The force and aerodynamic coefficients obtained were plotted and the results were reported.