Aerodynamic Design for Monorail Train Nose

Abstract

Railway train aerodynamic problems are closely associated with the flows of air occurring around train. Much effort to speed up the train system has been concentrated on the improvement of electric motor power rather than understanding the flow around the train. This has led to larger energy losses and efficiency reduction of the train system. The need for study of aerodynamics around train arises as the flows around train are more disturbed due to turbulence of the increased speed of the train, and consequently the flow energies are converted to aerodynamic drag, noise and vibrations. To finding out the pressure distribution on to the nose surface the wind tunnel experiments are well known but it is very costly and time consuming affair. More over this technique requires very high skilled personnel and that's why the need for an alternative method to solve aerodynamic problem arises. The primary intention is generate the shape which should be fit in given space. Here the approach is first design based on the 2D different configuration shapes for different cases. To make the 3D model the model is divided in to the three 2D shapes which are the extreme shapes of the monorail train nose. The extreme sections means where the pressure due to the flow of air becomes dominant in the train body, three extreme sections like mid section from the side, top section which having maximum area and front section is the section of the car body. All these three shapes are to be solved by CFD analysis and the shape satisfies all requirements like limitation on negative pressure generation, minimum coefficient of drag, and lift can be selected as optimized shape to generate final 3D shape. This method is very less time consuming and if any modification is required then can be change very promptly in 2D. The main intention is to achieve the streamlined shape for monorail. Once the 3D shape is developed then the final CFD analysis can be done on the model to observe the streamlines on the body. CFD analysis is done on various shapes of configurations of monorail train nose with Fluent 6.3.