A&G • February 2013 • Vol. 54 1.25 The continuous flow of matter that escapes out of the solar gravitational well is known as the solar wind. As the material flows out of the Sun, it is accelerated to between 400 and 800 km s. Through this continuous flow of material, the Sun loses more than one million tonnes every second. But this is just a tiny fraction, corresponding to 2 × 10 of a solar ma...

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...

Damavand is a large dormant stratovolcano in the Alborz Mountains of northern Iran located in one of the most populous provinces, which could be adversely affected by tephra fall from Damavand. The youngest known eruption is a lava flow on the western flanks with an age of 7.3 ka. The volcanic products are predominantly porphyritic trachyandesite. Three major young pumice deposits, named here a...

Some difficulties are encountered when simulating super-critical Reynolds number (Re) flow over curved surfaces of a building in a low speed boundary layer wind tunnel (BLWT) due to the sensitivity of the flow to Re. Surface roughness on the façade of the cylinder can affect the location of the separation point and the extent of the wake on the leeward face, upon which the wind-induced response...

Recent work by S. Lentz et al. documents offshore transport in the inner shelf due to a wave-driven return flow associated with the Hasselmann wave stress (the Stokes–Coriolis force). This analysis is extended using observations from the central Oregon coast to identify the wave-driven return flow present and quantify the potential bias of wind-driven across-shelf exchange by unresolved wave-dr...

An experimental investigation is performed to assess the characteristics of the fluid– structure interactions and microburst-induced wind loads acting on a wind turbine model sited in microburst-liked winds. The experiment study was conducted with a scaled wind turbine model placed in microburst-like winds generated by using an impinging-jet-typed microburst simulator. In addition to quantifyin...

We study the generation of surface waves on water as a bifurcation phenomenon. For a critical wind-speed there appear traveling wave solutions. While linear waves do not transport mass (in the mean), nonlinear effects create a shear-flow and result in a net mass transport in the direction of the wind. We derive an asymptotic formula for the average tangential velocity along the free surface. Nu...

Title of dissertation: DEVELOPMENT OF A TIME-ACCURATE VISCOUS LAGRANGIAN VORTEX WAKE MODEL FOR WIND TURBINE APPLICATIONS Sandeep Gupta, Doctor of Philosophy, 2006 Dissertation directed by: Minta Martin Professor J. Gordon Leishman, Department of Aerospace Engineering A second-order accurate model has been developed and validated for modeling the unsteady aerodynamics of a wind turbine. The free...

The 3-D structure of the solar wind varies dramatically along the Sun’s activity cycle. In the present paper we focus on some properties of the polar solar wind. This is a fast, teneous, and steady flow (as compared to low-latitude conditions) that fills the high-latitude heliosphere at low solar activity. The polar wind has been extensively investigated by Ulysses, the first spacecraft to perf...

Currently there are few observations of the urban wind field at heights other than rooftop level. Remote sensing instruments such as Doppler lidars provide wind speed data at many heights, which would be useful in determining wind loadings of tall buildings, and predicting local air quality. Studies comparing remote sensing with traditional anemometers carried out in flat, homogeneous terrain o...