Aerodynamic Drag Reduction of an Intercity Bus through Surface Modifications - A Numerical Simulation 2019-28-0045

The maximum power produced by the Engine is utilized in overcoming the Aerodynamic resistance while the remaining has been used to overcome rolling and climbing resistance. Increasing emission and performance demands paves way for advanced technologies to improve fuel efficiency. One such way of increasing the fuel efficiency is to reduce the aerodynamic drag of the vehicle. Buses emerged as the common choice of transport for people in India. By improving the aerodynamic drag of the Buses, the diesel consumption of a vehicle can be reduced by nearly about 10% without any upgradation of the existing engine. Though 60 to 70 % of pressure loads act on the frontal surface area of the buses, the most common techniques of reducing the drag in buses includes streamlining of the surfaces, minimizing underbody losses, reduced frontal area, pressure difference between the front & rear area and minimizing of flow separation & wake regions. As city buses won’t have cargo storage constraints roof optimization can be done to reduce the drag coefficient value. A base model of the intercity bus has been taken and analyzed using ANSYS Fluent for drag and lift coefficient values at regular operating conditions. New models have been derived from the existing model by optimizing some areas of the vehicle which won’t affect passenger comfort to obtain uniform flow, less wake region, reduced drag coefficient value and minimized pressure differential. A maximum of 25 % reduction of drag value has been obtained which will increase the fuel economy by about 5-8 %.