Windscreen angle and Hood inclination optimization for drag reduction in cars

Drag reduction in cars is evident by the angle of windscreen inclination. Drag reduction helps to reduce emissions. Windscreen inclination affects the height of the vehicle. The curvature of the windscreen should be optimized in order to avoid the cross-wind effect. The dimensions of the windscreen of a car are obtained from works of literature and modelled in modelling software. Firstly, the effect on windscreen inclination with respect to drag is studied using ANSYS Fluent. CFD analysis is done with inlet velocity of 25 m/s and the influence of vehicle height against the drag coefficient is identified. By varying inlet velocity of air, the pressure contours in the frontal hood of the vehicle are studied. Hood inclination should be optimized for minimum drag. From the studies, it is observed that 32 back windscreen angle gives the minimum Co. The front windscreen angle should be below 45 for minimum drag and Co is decreasing linearly as hood inclination increases. The angle of windscreen inclination proposed such that it does not affect driver visibility. It should accumulate the raindrops and dirt effectively. Windscreen inclination angle selected such that it does not affect the stability due to change in vehicle dimensions. The drag coefficient is reduced by optimizing the frontal area. The windscreen inclination is obtained by taking visibility concerns into account. From the studies, It is observed that front windscreen angle 60, back windscreen angle 32 and 15 hood inclination gives the minimum Co as 0.320. (C) 2019 The Authors. Published by Elsevier Ltd.