The high cost of wind tunnel testing and the ongoing reduction in national wind tunnel facilities are forcing the aerospace engineering community to increasingly rely on computational fluid dynamics (CFD) to predict the performance of new aircraft designs. However, most aerospace applications are characterized by flows that exhibit large-scale unsteady turbulence and the accurate prediction of ...

Hydroelectric power plants’ open-type surge tanks may be built in mountains subject to the provision of atmospheric air. Hence, a ventilation tunnel is indispensable. The air flow in the ventilation tunnel is associated with the fluctuation of water-level in the surge tank. There is a great relationship between the wind speed and the safe use and project investment of ventilation tunnels. To ob...

A three dimensional numerical wind tunnel based on the Navier-Stokes equations for viscous, incompressible fluid and LES method is established. Incoming wind field is generated based on the AIJ guidelines (2004). The numerical wind tunnel is validated against experimental results. A low-rise building with green roof is tested in the numerical wind tunnel. The results show that the green roof re...

This paper investigates a novel method for the control of “morphing” aircraft. The concept consists of a pair of winglets with adjustable cant angle, independently actuated and mounted at the tips of a baseline flying wing. The general philosophybehind the conceptwas that for specificflight conditions such as a coordinated turn, the use of two control devices would be sufficient for adequate co...

A 15by 15-cm supersonic wind tunnel application of a one-dimensional laser beam scanning approach to shock sensing is presented. The measurement system design allowed easy switching between a focused beam and a laser sheet mode for comparison purposes. The scanning results were compared to images from the tunnel Schlieren imaging system. The tests revealed detectable changes in the laser beam i...

Buffeting is an aeroelastic phenomenon which plagues high performance aircraft, especially those with twin vertical tails like the F/A-18, at high angles of attack. This buffeting is a concern from fatigue and inspection points of view. By means of wind-tunnel and flight tests, this phenomenon is well studied to the point that buffet loads can be estimated and fatigue life can be increased by s...

Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer (ABL) by using roughness devices such as vortex generators, floor roughness, barrier walls, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices o...

The measurement of aerodynamic forces and moments acting on an aircraft model is important for the development of wind tunnel measurement technology to predict the performance of the full scale vehicle. The potentials of an aircraft model with and without winglet and aerodynamic characteristics with NACA wing No. 65-3218 have been studied using subsonic wind tunnel of 1 m × 1 m rectangular test...

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...

An experimental study is conducted to investigate condensate drainage and retention and the attendant thermalhydraulic effect associated with changes in surface hydrophilicity on air-conditioning evaporators. Three heat exchangers that have controlled wettability covering a range of contact angles and a baseline untreated aluminum heat exchanger are tested. Results from dynamic dip-testing as w...