In this study, the performance of a ducted WIND turbine is compared with a bare one using WIND TUNNEL results. Ducted turbines are a type of small WIND turbines, which consist of a diffuser surrounding the rotor. The duct makes more air flow in rotor plain and as a result augments power production. The blade was fabricated, using resin polyester armed by glass fiber. Duct is formed by sheet metal rolling in slope to have an acceptable appearance. According to BEM design, predicted power for the bare turbine is 300W in WIND velocity 10 m/s considering 20% loss due to bearing resistant, rotor inertia, and generator efficiency. WIND TUNNEL investigation revealed 165W power experimentally for bare WIND turbine. The evaluation of the system in the WIND TUNNEL showed that the power augmentation of the ducted system compared to the bare one was 37% higher on average. The maximum power augmentation of the ducted turbine was 286W. The rotor speed of ducted turbine was 61% more than the bare turbine, which increased the speed of the tip of the blade.

This paper presents the design, computational analysis and experimental study of passive device configurations which utilized in the Ankara WIND TUNNEL to simulate the atmospheric boundary layer within the test section. The study here is part of a joint project between the Aerospace and Civil Engineering Departments at Middle East Technical University, which involves testing of high-rise building models in the Ankara WIND TUNNEL. The design consists of spires and rows of cubical surface roughness elements at the inlet. The preliminary computational analysis shows that the current design may provide the desired boundary layer thickness at about 4.0 m downstream of the test section inlet, which leaves enough room for the building models to be placed in the test section. This study also helps obtaining a preliminary understanding of the boundary layer development and reducing the TUNNEL operation time and cost during the actual experimentation phase. At the end, experimental results show acceptable results of this study.

WIND erosion is a key process in land degradation worldwide, especially in arid and semi-arid regions of Iran. This phenomenon is affected by many soil characteristics. The main objective of this study was to estimate the WIND erosion threshold velocity using easily measurable soil characteristics along with data mining methods. For this purpose, WIND erosion threshold velocity was measured in 100 areas in Fars province using a portable WIND TUNNEL. WIND erosion threshold velocity was predicted by a support vector regression algorithm using easily measurable soil properties. In this regard, a genetic algorithm was used in order to obtain a set of parameters effective in estimating WIND erosion threshold velocity. The results showed that the characteristics of soil moisture (r = 0.77), the size distribution of soil particles including the mean weight diameter of aggregate (r = 0.87) and the WIND-erodible fraction of soils (r = -0.81), penetration resistance (r = 0.75), and organic matter (r = 0.33) have a high and significant correlation with WIND erosion threshold velocity and play a key role in determining the threshold velocity of WIND erosion in the region. According to the evaluation criteria, the combined support vector regression model with the genetic algorithm had the best performance and the most accurate estimate for WIND erosion threshold velocity (RMSE = 0.53 and R2 = 0.92) and can be a promising method for estimation of WIND erosion threshold velocity.

One of the throats in designing hypersonic WIND TUNNEL is the design of heater. The purpose of this study is designing a heater with ceramic cored, in 1800K temperature for preventing air condensation in WIND TUNNEL. In initial part of design the fluid flow and heat transfer equation have been solved through an inviscid engineering code. This code estimates the temperature of transient outlet flow with static physical and thermodynamic properties of fluid and solid, geometrical dimensions of bed and wall distribution temperature. The final part of design has been solved with computational methods and using of Navir Stocks and energy equation, with K-ω SST turbulence model. The solver is 2nd order and pressure base. The numerical results are in acceptable agreement with experimental. By parameter analysis, various design for obtaining a suitable heater have been evaluated. The evaluated parameters are height, diameter, porosity of the bed and the diameter of the hole and diameter of the bed. The results show that the diameter of the hole, the diameter of the bed, the height and prosity the most important parameters in the design of the heating bed and have a great impact on the temperature of the exhaust air and the duration the test respectively. 14% increase or decrease of each parameter increase 61, 51, 28, and 8% of execution time and 6, 3, 2 and 1. 8 % of the output air temperature respectively. The hole diameter and prosity of the heater bed are two important parameters in determining the dimension of the heater bed. Finally with using of the results the final design has been modified with bed diameter of 0. 45 meter, height of 1. 7 meter, hole diameter of 3 millimeter and prosity 0. 2512.