Context. Thermal wind emission in the form of free-free and free-bound emission is known to show up in the infrared and radio continuum of hot and massive stars. For OB supergiants with moderate mass loss rates and a wind velocity distribution with β ≃ 0.8 . . . 1.0, no influence of the wind to the optical continuum, i.e. for λ <∼ 1.0 μm, is expected. Investigations of stellar and wind paramete...

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...

the technique used to control the airflow is based on the electro-hydrodynamic actuator which is also called plasma actuator. this actuator ensures the airflow control thanks to the electric wind created by the electrical corona discharge. this ionic wind is developed at the profile surface tangential to the initial free airflow so that it has a significant effect on the boundary layer flow. th...

The aerodynamic admittance function (AAF) has been widely invoked to relate wind pressures on building surfaces to the oncoming wind velocity. In current practice, strip and quasi-steady theories are generally employed in formulating wind effects in the along-wind direction. These theories permit the representation of the wind pressures on building surfaces in terms of the oncoming wind velocit...

An advanced wind tunnel has been introduced as a facility for road vehicle development at the Kindai University (KURING). In this paper, the features of this wind tunnel, which can generate arbitrary patterns of time-varying wind velocities, are first described. There are four representative airflow patterns: steady wind with constant velocity, pulsating wind with oscillating velocity, gusts of...

to enhance the understanding of the impact of obstacle buildings on pollution transportationand dispersion in the atmospheric boundary layer, it is necessary to know the atmospheric flow characteristics over terrains. wind flow characteristics in a boundary layer over a step-shaped cliff topography model with rough and smooth surfaces were studied numerically using computational fluid dynamics ...

Field measurements of the wake flow produced from a 2-MW Enercon E-70 wind turbine were performed using three scanning Doppler wind lidars. A GPS-based technique was used to determine the position of the wind turbine and the wind lidar locations, as well as the direction of the laser beams. The lidars used in this study are characterized by a high spatial resolution of 18 m, which allows the de...

Wind stress, waves, stratification, velocity profiles, and surface fields of radial velocity and acoustic backscatter intensity were measured along a drift track 50 to 150 km off Point Arguello, California. On March 8, 1995, the wind increased from calm to 12 rn/s from the SE, opposing swell from the NW. It increased to15 rn/s at noon UTC on March 9, remained steady over the next 12 hours, brie...

the aim of the present study was to investigate the influence of nozzle configurations on spray drift and explain the influences using several atomization characteristics (length of spray sheet, spray angle, velocity distribution of flow field, fluctuation of velocity, and droplet size). nozzles manufactured by one company (lechler gmbh, germany) were tested by spraying local tap water in a win...

In this study, large-eddy simulations (LESs) were performed to investigate the effects of changing wind direction on the turbine wakes and associated power losses in the Horns Rev offshore wind farm. In the LES framework, the turbulent subgrid-scale stresses are parameterized using a tuning-free Lagrangian scale-dependent dynamic model, and the turbine-induced forces are computed using a dynami...