Numerical and Analytical Study of a Battery Powered Vehicle Moving in a Vacuum Tunnel

The present work focuses on an aerodynamic and heat transfer study of a battery powered vehicle moving in a vacuum tunnel. The conducted research was based on analytical analysis and numerical calculations. Four different vacuum levels in the tunnel were considered&mdash
100 Pa, 1 kPa, 10 kPa and 100 kPa&mdash
and two distinct velocities of the vehicle&mdash
125 and 166 m/s&mdash
to address subsonic and supersonic conditions. It allowed defining limitations related to vacuum transportation in terms of velocity of the vehicle and a blocking ratio of the tunnel. Power consumption and drag coefficient for the considered tunnel pressures were analyzed. The cooling analysis of the batteries by passing air was performed numerically and analytically in the function of flow conditions in the tunnel. It gave some insight into main problems related to cooling of the batteries under low pressure and possible directions to solve it. It was shown that the proposed analytical model compared satisfactorily with the numerical results.