A large eddy simulation (LES) program with the Smagorinsky subgrid-scale model has been used to study cross natural ventilation in buildings, which has experimental data available from on-site measurements and a wind tunnel. Since natural wind changes direction over time, it is hard to reproduce this effect in a conventional wind tunnel where the “wind” direction is fixed. There are discrepanci...

Introduction Cable stayed bridges are a feasible choice for middle length spans and can be also an alternative to suspension bridges in the range of 1000 m spans. In the last three years, cable stayed bridges having more than 1 km span have been built in China (Sutong Bridge, 1088 m and Stonecutters Bridge, 1018 km). The increasing in length implies higher aeroelastic interaction with wind acti...

In this paper, wind tunnel results of a real time optimization of a morphing wing in wind tunnel for delaying the transition towards the trailing edge are presented. A morphing rectangular finite aspect ratio wing, having a wind tunnel experimental airfoil reference cross-section, was considered with its upper surface made of a flexible composite material and instrumented with Kulite pressure s...

The theory, methods, and applications of the videogrammetric model deformation (VMD) measurement technique used at NASA for wind tunnel testing are presented. The VMD technique, based on non-topographic photogrammetry, can determine static and dynamic aeroelastic deformation and attitude of a wind-tunnel model. Hardware of the system includes a video-rate CCD camera, a computer with an image ac...

A computer program has been developed to calculate inviscid transonic flow over a swept wing in a wind tunnel with specified normal flow at the walls. An approximately orthogonal computational grid which conforms to the wing and the tunnel walls was developed for application of the JamesonCaughey finite volume algorithm. the full potential equations in fully conservative form using line relaxat...

An open-jet wind tunnel operating within an anechoic chamber was developed for the purpose of the study of V/STOL noise mechanisms. An existing low-speed conventional hardwalled wind tunnel was modified to operate as an open-jet tunnel; an anechoic chamber was then constructed around the test section. The resulting aerodynamic and acoustic characteristics of the tunnel are discussed. This work ...

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...