This work involves numerical simulations based on finite volume method to study the effects of different factors on the aerodynamic drag on a vacuum tube train running at subsonic and transonic speeds in a partially vacuum tunnel. Investigation includes the study of the effects of the shapes of head, tail, vacuum pressure and also blockage ratio of the tunnel on aerodynamic drag on a high speed train. The simulation is performed by using fluent software. Two dimensional, axisymmetric, compressible Navier-Stokes equations were solved by using k-ε turbulent modeling. Five different blockage ratios at five different speeds of the train have been considered. The simulated results show that, the blockage ratio and different working vacuum pressure significantly affects the aerodynamic drag of the train in a tunnel. Investigations with respect to different shapes of the head as well as that of the tail indicate the optimum shape for minimum drag.

Tire is an integral part of any vehicle, providing contact between the vehicle and the surface on which it moves. Forces and moments generated at the tire-road interaction imparts stability and control of motion to the vehicle. These forces and moments are functions of many variables such as slip, slip angle, contact pressure, inflation pressure, coefficient of friction, temperature, etc. This thesis deals with the effect of temperature on the lateral force, the longitudinal force and the self-aligning moment. The analysis is done at different tire surface temperatures (20 o C, 40 o C, 60 o C). Since the experimental set up with the tire mounted is complex and expensive, we use a hybrid approach in which we take the results from the experiments done by the researchers on a sample piece of tire rubber at various temperatures. Then, we do the steady state analysis in ABAQUS considering the variation of coefficient of friction, slip speed and the elastic modulus of rubber with temperature. The steady state numerical results from ABAQUS at different surface temperatures are compared with the modified magic formula, i.e., PAC2002 tire model, to capture the temperature effect. After validating the variations of steady state forces and moments from ABAQUS with the modified PAC2002, we use these steady state tire models to do the transient analysis in order to capture the effect of temperature on the transient response of tire forces and moments for different driving conditions of acceleration, braking and double lane change using MSC ADAMS/CAR.