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...

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...

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...

During the past decade, the Navy has considerably improved its capabilities in aircraft/weapon integration. In 1989 it took more than 400 hours of wind tunnel testing, which cost 1,5000,000, and 20 flights to clear the JSOW from the F-18 to Mach 0.95. This year the MK-83 JDAM was cleared after only 60 hours of wind tunnel testing and five flights to the full F-18 aircraft envelope of Mach 1.3. ...

This article presents analytical and computational analysis of the influence of the wind tunnel walls on transonic airfoil tests. The goal is to quantify the effects of the wind tunnel walls and characterize the key parameters affecting the flow field in order to construct a numerical model to realize experimental data corrections. Firstly, the experimental data are compared with well-documente...

This work presents estimates of time histories of pressure coefficients at several taps on the roof of a 1/200 model of a 200 x 100 x 20 ft low-rise building with a 1/24 slope gable roof building. The estimates were obtained using a large eddy simulation (LES). The first and second moments as well as peaks for the time histories are compared with those obtained in boundary layer wind-tunnel mea...

Wind tunnel testing using reduced scale topography models is a mature technique [1] that enables the investigation of various aspects of wind flows from pollutant dispersion [2] to wind field modifications [3] affected by terrain. Alternatively, or in conjunction with a wind tunnel study, a rigorously developed computational technique would have the potential to provide additional and useful in...

A wind tunnel bioassay system to screen mosquito repellents is described. A wind tunnel is utilized to exploit the upwind flight response of host-seeking mosquitoes. Mosquitoes within the wind tunnel are activated with human breath, fly upwind, and land on heated chick skins. This behavioral sequence results in a consistently high percentage of the test population approaching repellent or contr...