The Reynolds Stress Model (RSM) is adopted to simulate the wind turbine wake and the simulation results are compared with the wind tunnel test data, simulation results from the standard k-ε model and a modified k-ε model. RSM shows good performance in predicting the turbine wakes velocity, turbulence intensity and the kinetic shear stress, while the k-ε based models fail to predict either wakes...

This paper presents an exponentially stable nonlinear wind velocity observer for fixed-wing unmanned aerial vehicles (UAVs). The observer uses a model of the aircraft combined with a GNSS-aided inertial navigation system (INS). The INS uses an attitude observer together with a pitot static probe measuring dynamic pressure in the longitudinal direction as well as the airspeed. The observer is ab...

the shape of wake behind a wind turbine is normally assumed to have a hat shape for the models used in wind farm layout optimization purposes; however, it is know from experimental tests and numerical simulations that this is not a real assumption. in reality, the results of actual measurements and detailed numerical simulation show that the velocity in wake region has a s-shape profile. the pr...

Sand and dust storms are natural events that occur widely around the world, mostly in dry and bare lands. Over thepast decade a large part of Iran has been affected by this phenomenon, and Tehran has not been excluded from thisevent. Therefore, having knowledge of spatiotemporal frequency variations can aid us in future management andstorm trajectory assessment. In this study the synoptic anemo...

To elucidate the wind-direction dependence of rotor performance in closely spaced vertical-axis wind turbines, wind-tunnel experiments were performed at a uniform velocity. In experiments, pair/trio three-dimensional printed model turbines with diameter D = 50 mm was used. The systematically by applying incremental adjustments to gap g and rotational direction each changing direction. For tande...

The shape of wake behind a wind turbine is normally assumed to have a hat shape for the models used in wind farm layout optimization purposes; however, it is know from experimental tests and numerical simulations that this is not a real assumption. In reality, the results of actual measurements and detailed numerical simulation show that the velocity in wake region has a S-shape profile. Th...

wind speed is one of the characteristics of wind energy which its data is extracted from meteorological stations. in this study, the data obtained from the weather station in the city eqlid during a ten-year period has been used. weibull distribution was chosen as the best distribution function using fitting tests and estimation of some statistical parameters. the results showed that the averag...

This paper introduces an equation for determining instantaneous and final velocity of a sprinter in a 100 m run completed with a wind resistance ranging from 0.1 to 4.5 m/s. The validity of the equation was verified using the data of three world class sprinters: Carl Lewis, Maurice Green, and Usain Bolt. For the given constant wind velocity with the values + 0.9 and + 1.1 m/s, the wind contribu...