a new title

##COMMENTS BY GRADER

Hey Ramprasad,

Good job on completing the challenge. One thing I'd like to point out is that in the second paragraph, you mentioned mesh numbers. You can say it as number of elements in the mesh instead.

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The Ahmed body is a simplified car used in automotive industry to investigate the influence of the flow structure on the drag. As most of the road vehicles can be classified as bluff bodies which move in the ground vicinity, a major contribution to the aerodynamic drag stems from pressure drag created by the low pressure prevalent in the separated flow region of vehicle base. Thus, It is evident that there is a need for detailed information about the structure of flow in the wake and its variation with changes in body geometry, to improve fuel efficiency by reducing aerodynamic drag.

In these simulations, the variation of the velocity profile, in the wake region, with an increase in the mesh count is observed. The velocity of the vehicle is taken as 55 m/s. Therefore the Reynolds number, based on length of the body is 3.91*10^6. The Ahmed body has a slant of 20 degrees. The mesh numbers considered are 84810, 105403, `330274, 496728. The drag coefficient of as calculated from these meshes are 0.65, 0.496, 0.491, 0.342. The drag coefficient as obtained by the 0.49 million cells is observed to be closest to the actual value of 0.296. The high difference(15%) in values of the drag may be explained by the coarseness of the mesh, though the recirculation regions are evident with the 0.496 million cells.

From the velocity vector plots, recirculation regions are observed in the rear of the model both in the XY and the YZ planes. This contributes to the negative pressure observed in the rear surface.