boundary layer growth and hence displacement thickness are the key factors in shock position over aerodynamical surfaces at transonic regimes. since boundary layer growth is a function of free stream reynolds number and also of the transition location, the free stream reynolds number and also the other parameters involved in the boundary layer growth and its transition location are determinant ...

The sound barrier for bullet trains remains a challenge due to the piston effect causing compression waves at entry and exit of tunnel. air ahead train nose is compressed, wave propagates through tunnel speed exits with generation micro pressure waves. It gives rise complex pattern comprising & expansion tail leading positive around suction tail. This intended provide exhaustive input prope...

Experimental studies were carried out in the 0.6 m×0.6 m continuous transonic wind tunnel of CARDC order to investigate flow characteristics slotted test section. results show that root-mean-square deviation axial Mach number model area is above 0.01 when section 1.0.Numerical simulation under same conditions section, together with experimental indicate tow phenomena may directly cause fluctuat...

under investigation. The early models to solve Navier-Stokes equation for a laminar flow in porous tube were proposed in Berman [1] and Yuan [2] and extended by Bernales [3]. Berman [1] presented a solution to the two-dimensional model in laminar flow in channels with uniform wall suction. This study was extended to cylindrical coordinates to investigate suction as well as injection in flow alo...

shock formation due to flow compressibility and its interaction with boundary layer has inappropriate effects, such as drag increase and flow separation. many methods have been proposed for reduction of these effects, such as vortex generator, suction, and blowing. this paper numerically studies the problem of flow control for naca0012 airfoil with porous media at transonic flow. porous media, ...

A series of NASA/Boeing cooperative low speed wind tunnel tests was conducted in the National Transonic Facility (NTF) between 2003 and 2004 using a semi-span high lift model representative of the 777-200 aircraft. The objective of this work was to develop the capability to acquire high quality, low speed (flaps down) wind tunnel data at up to flight Reynolds numbers in a facility originally op...

In the German Aerospace Center, DLR, an internal project has been launched to investigate different UCAV configurations. One aspect, covered by the Institute of Aeroelasticity and the Institute of Aerodynamics and Flow Technology, is the wind tunnel test of a UCAV wing in subsonic and transonic flow. The model shall show measurable static aeroelastic deformations. Main goals of the tests will b...

This paper describes a modeling method and a new optimal control approach to investigate a Mach number control problem for the NASA Ames 11-Foot Transonic Wind Tunnel. The flow in the wind tunnel is modeled by the 1-D unsteady Euler equations whose boundary conditions prescribe a controlling action by a compressor. The boundary control inputs to the compressor are in turn controlled by a drive ...

The dynamic longitudinal-stability characteristics of a st,andard wind tunnel interference model have been investigated in free flight over a Mach number range of 0.92 to I, 35.. Measurements of lift-curve slope and manoeuvre margin were obtained, and are compared vjith results from transonic-tunnel tests under low blockage conditions. The analysis was extended to obtain damping derivatives to ...