the occurrence of dust storms and their sources in the southern and central parts of iran during the period of 2002 to 2009 was investigated. for this purpose, the meteorological and synoptic data, data from the middle and upper atmosphere, and wind flow tracking model were used. dust storms and nddi were traced using satellite imagery from fasa, shiraz, and bushehr stations. analysis of the gr...

Straw checkerboard barrier (SCB) is the most representative antidesertification measure and plays a significant role in antidesertification projects. Large-eddy simulation and discrete-particle tracing were used to numerically simulate the wind sand movement inside the straw checkerboard barrier (SCB), study the movement characteristics of sand particles, find the transverse velocities of sand ...

tracing fidelity is controlled by the flow rates of helium, liquid soap and air in HFSB production. A characteristic time response, defined as the ratio of slip velocity and the fluid acceleration, is obtained. The feasibility of performing time-resolved tomographic PIV measurements over large volumes in aerodynamic wind tunnels is also studied. The flow past a 5-cm-diameter cylinder is measure...

For analyzing and interpreting results of flow simulations, particle tracing is a well established visualization method. In addition, it is a preliminary step for more advanced techniques like line integral convolution. For interactive exploration of large data sets, a very efficient and reliable particle tracing method is needed. For wind channel experiments or flight simulations, large unstru...

one of the most important advantages of particle simulation as compared to fluid simulation is the capacity for working with and tracing particles. in particle simulations, the test particle method is usually used to get some idea of the behavior of plasma or other substances. in this method, first, a small number of particles are injected into the frame of static electromagnetic fields. then, ...

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. ...

[1] We examine the formation mechanism of the South China Sea Warm Current in winter, using a high-resolution, numerical model. The current, noted for its ability to flow against the prevailing northeast monsoon in winter, has received considerable attentions in recent years. The collective wisdom from previous models points to two likely generation scenarios: occasional wind relaxation or the ...

This paper discusses scientific visualization of scalar and vector fields, particularly relating to clouds and climate modeling. One cloud rendering method applies a 3-D texture to cloudiness contour surfaces, to simulate a view from outer space. The texture is advected by the wind flow, so that it follows the cloud motion. Another technique simulates multiple scattering of incident light from ...

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 the past, wind towers were applied as the main architectural part of building construction in the desert areas of Iran. These almost high structures were used as cooling load suppliers at residential buildings. In the present study, the effect of symmetric four-sided wind tower in flow induction to the bottom space has been analysed by using a wind tunnel and numerical simulations. In the nu...