high speed wind tunnels are widely used in the study of fluid flow behavior around various objects. the air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. to arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

in this paper the separation of saffron stigma from stamen and petal in a vertical wind tunnel has been evaluated. a wind tunnel with adjustable speed of 0.1 m s-1 intervals has been developed and used for the experiments. floating velocities of flower components (petal, stigma and stamen) were measured at one, eight, 38 and 60 hours after harvesting. subsequently, the separation was tested by ...

This paper brings together considerations of gas leak behaviour and leak detector design and use, with a view to improving the detection of low-pressure natural gas leaks. An atmospheric boundary layer wind tunnel has been used to study ground–based releases of methane at full scale over distances of up to 3 m, under controlled conditions. These scales are relevant to the detection of natural g...

High speed wind tunnels are widely used in the study of fluid flow behavior around various objects. The air flow in the starting step of supersonic wind tunnels is transient including strong shock waves caused by the interaction of the tunnel main stream and the boundary layer at walls. To arrive in running step, the tunnel must be designed so as these waves leave immediately the test section. ...

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...

Feeder is one of the airships of the Multibody Advanced Airship for Transport (MAAT) system, under development within the EU FP7 project. MAAT is based on a modular concept composed of two different parts that have the possibility to join; respectively they are the so-called Cruiser and Feeder, designed on the lighter than air principle. Feeder, also named ATEN (Airship Transport Elevator Netwo...

This paper presents experimental and computational investigation of the dispersion mechanisms of a passive-type tracer gas, done in the scaled, three-dimensional model of a street canyon. At a low wind speed of 1.67m/s and neutral atmospheric conditions, dispersion of pollutant has been investigated within an isolated street canyon at an aspect ratio of 1 for perpendicular wind orientation (90)...

It is highly important in Japan to choose a good site for wind turbines, because the spatial distribution of wind speed is quite complicated over steep complex terrain. We are developing the unsteady numerical model called the Research Institute for Applied Mechanics, Kyushu University, COMputational Prediction of Airflow over Complex Terrain (RIAM-COMPACT). The RIAMCOMPACT is based on the larg...

The paper reports on wind tunnel experiments with an elastically suspended circular cylinder vibrating under the excitation of natural wind of high turbulence degree. The natural wind turbulence was simulated by superposing the low frequency part of the natural wind turbulence on the background high frequency turbulence of the wind tunnel flow. This was done by controlling the propeller rotatio...