M. Mani, M. R.soltani, and A. Haghiri,
Volume 23, Issue 1 (7-2004)
Abstract
Several experiments involving two-dimensional and axisymmetric bodies have been carried out in a Trisonic wind tunnel at supersonic speeds to investigate and analyse the measured values of base pressure and to compare them with those from the theoretical methods. The objective of the experiments was to obtain an appropriate method for processing the results of wind tunnel tests on rockets or aircraft having base area, hence, base drag. Among numerous semi-empirical methods available for two-dimensional and axisymmetric geometry, the methods presented by Chapman, Korst and Tanner have been utilized to calculate values of base pressure for comparison with the experimental findings for the same model. The results indicate that the pressure increase for the 2-D model with a steplike base is greater that of the axisymmetric model with the same conditions. The experimental results for all cases considered in this investigation compare well with those from existing the theoretical method developed by Tanner
M. R. Heidari, M. R. Soltani, M. Taeibi-Rahni, and M. Farahani,
Volume 24, Issue 2 (1-2006)
Abstract
A series of supersonic wind tunnel tests on an ogive-cylinder body were performed to investigate the pressure distribution, the boundary layer profiles, and the flow visualization at various angles of attack. All tests were conducted in the trisonic wind tunnel of the Imam Hossein University. The theoretical shock angle at different model positions compared well with those we obtained via Schilerian results. The static surface pressure results show that the circumferential pressure at different nose sections vary significantly with angle of attack. However, minor changes in the circumferential pressure signatures along
the cylindrical part of the body were observed. The total pressure measurements in the radial direction, perpendicular to the incoming flow, vary significantly both radially and longitudinally (along body length). The boundary layer thickness increases along the body. At the beginnig and at the midle part of the cylinderical portion of the body, the boundary layer thickness increases uniformly with increasing angle of attack. However, this situation differs near the end of the body. Our measurements indicated a turbulent boundary layer along the model, which is probably due to the high turbulence level in the tunnel test section.
