sand dunes mobility is one of the serious problems in arid regions. since wind regime is one of the important factors in sand dunes formation, its frequency, direction and magnitude can be effective. amount of wind energy and its directional variability (wind regime) have significant control on the morphology and maintenance of aeolian landforms. by recognizing of morphometric and morphodynamic...

A wind tunnel investigation was performed to study the flow field over a 70° swept sharped edge delta wing model at high angles of attack. The experiments were conducted in the subsonic wind tunnel at the Department of Mechanical Engineering, Sharif University of Technology. Velocity profiles have been measured using a special pitot tube and hot wire anemometer at angles of attacks of 10 to 35 ...

Scattering of electromagnetic waves by turbulence is considered. It is shown that Doppler velocity (the ratio of Doppler shift and Bragg wave number) includes two terms: The first is the mean radial velocity in the scattering volume, and the second is what we call the “correlation velocity,” caused by a correlation between the fluctuations of velocity and those of refractive index. The correlat...

Turbulent wake of wind turbine will reduce the power output of wind farm. The access to real turbulent wake of wind turbine blades with different spatial and temporal scales is provided by the pulsed Coherent Doppler Lidar (CDL) which operates by transmitting a laser beam and detecting the radiation backscattered by atmospheric aerosol particles. In this paper, the authors discuss the possibili...

To facilitate the research of mobile robot based odor source localization (OSL) and evaluate different strategies for the OSL, numerical simulation of odor plume in indoor ventilated environments is addressed. On the basis of the FLUENT software package, the 3-D wind field of an indoor ventilated environment is calculated using the Reynolds average approach, where the real wind velocity measure...

A fraction of the radiation produced by an accretion disk may be Thomson scattered by a wind flowing away from the disk. Employing a simple plane-parallel model of the wind, we calculate the polarization of the scattered radiation and find that its sign depends on the wind velocity, β = v/c. In the case, 0.12 < β < 0.78, the polarization is parallel to the disk normal, i.e., it is orthogonal to...

Cl = section lift coefficient c = local chord length D = fading-memory constant G = nondimensional circulation l = section lift force/length m = number of points used in sine series expansion of circulation function N = consecutive iterations convergence parameter r = perpendicular distance from vortex tol = iteration relative tolerance of conversion U1 = freestream velocity magnitude w = downw...

A novel short-term wind energy forecasting method, which is being developed under the UBDIBM renewable energy modeling initiative, is described in this paper. The paper starts with a brief review on the existing forecasting methods. Prediction models based on the physical (derived from Numerical Whether Prediction models) and Time Series approaches are discussed. The prediction errors under the...

Acoustic travel-time tomography allows one to reconstruct temperature and wind velocity fields in the atmosphere. In a recently published paper [S. Vecherin et al., J. Acoust. Soc. Am. 119, 2579 (2006)], a time-dependent stochastic inversion (TDSI) was developed for the reconstruction of these fields from travel times of sound propagation between sources and receivers in a tomography array. TDS...