Experimental and computational studies were performed to study the drag forces and the pressure distributions of a one-fifth scale model FIAT Linea at increasing yaw angle and two-vehicle platoon. Experiments were performed in the Uludag University Wind Tunnel (UURT) only for the yaw angles of 0 deg, 5 deg, and 10 deg due to the test section dimensional restriction. Supplementary tests were performed in the Ankara Wind Tunnel (ART) to evaluate the aerodynamic coefficients up to yaw angle of 40 deg. The test section blockage ratios were 20% and 1%, respectively, in the UURT and ART tunnels. The blockage effects for the yaw angles up to 10 deg were studied by the comparison of two wind tunnel results. The aerodynamic tests of two-vehicle platoon were performed in the ART tunnel at spacings of “x/L” 0, 0.5, and 1. Static pressure distributions were obtained from the model centerline and three vertical sections. In the numerical study, three-dimensional, incompressible, and steady governing equations were solved by star-ccm+ code with realizable k-ɛ two-layer turbulence model. Experimental and numerical Cp distributions and Cd values were found in good agreement for considered yaw angles and two-vehicle platoon. Maximum drag coefficient was obtained at yaw angle of 35 deg for both experimental and numerical calculations. The two-vehicle platoon analysis resulted with the significant drag coefficient improvement for the leading car at spacings of x/L  = 0 and 0.5, while for the tail car drag coefficient remained slightly above the vehicle in isolation.

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The wind loads on a stand-alone solar panel and flow field behind the panel were experimentally investigated in a wind tunnel under the influence of ground clearance and Reynolds number. The experiments were carried out at the chord Reynolds number of 6.4910 4 , 9.6910 4 , and 1.3910 5 encompassing turbulent flows and dimensionless ground clearance of 0, 0.5 and 0.6. The velocity and turbulence intensities were measured by a constant-temperature hot wire anemometer, and a pressure scanner system was used to static pressure measurements. It was found that the wind loads on the solar panel increased with ground clearance, while changed within a range of the uncertainties of the method with Reynolds number. So, the design-relevant wind loads were independent of the Reynolds number for the present test configurations, but they were significantly affected by the ground clearance. The velocity profiles demonstrated that the length of the recirculation region behind the panel increased with the reduction of the ground clearance, while decreased from the middle of the panel to the near edges, which is consistent with the pressure measurements.