In our previous experiments using a wind tunnnel, the flow in a two-dimensional curved diffuser with logarithmic spiral angle was clarified quantitatively about the variation of spiral angle and the existence of a guide vane. The wind tunnel method however requires much time for preparation of the experimental system and for the main experimental procedure . We have recently devised a new exper...

A videogrammetric technique developed at NASA Langley Research Center has been used at five NASA facilities at the Langley and Ames Research Centers for deformation measurements on a number of sting mounted and semispan models. These include high-speed research and transport models tested over a wide range of aerodynamic conditions including subsonic, transonic, and supersonic regimes. The tech...

We attempt to compute the dynamic wind loads on tall buildings in close proximity with large-eddy simulation. Computation is attempted on two building geometries on which strong interference effects have been reported in previous wind tunnel studies. The computation uses a commercial code and a simple model of turbulence characteristics of the incident wind flow. The computed along-wind and acr...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

In the opening decades of wind engineering research and application the typical focus was on the glamorous, highrise structure. These expensive projects could typically afford the high cost of a wind-tunnel study. As the relative cost of these studies has decreased over the last forty years, more conventional architecture has found its way into the wind tunnel. However, it is still quite rare f...

Considering the characteristics of wind tunnel tests, a position measurement system that can minimize the effects on the flow of simulated wind must be established. In this study, a motion-capture camera was used to measure the displacement responses of structures in a wind tunnel test, and the applicability of the system was tested. A motion-capture system (MCS) could output 3D coordinates usi...

An experimental study was conducted to investigate the interferences of wind turbines sited over hilly terrains in order to elucidate the underlying physics to explore/optimize design of wind turbines sitting over complex terrains for higher power yield and better durability. The experiments were conducted in an atmospheric boundary layer wind tunnel with wind turbines sited over two-dimensiona...

Ž . Plume clouds resulting from wildland fires pyrocumulus sometimes produce lightning discharges to ground. These discharges were found to carry positive charge to ground exclusively in several cases. Emission of space charge was observed from woody materials burned in the presence of an external electric field. Measurements done in a large wind tunnel for this study confirm and extend measure...