Aerodynamic Drag Reduction for a Generic Truck Using Geometrically Optimized Rear Cabin Bumps

Table 2

Grid independence test.

Total number of cells	Drag coefficient	Convergence time
Medium; (1,322,679 million)	0.442	110 minutes
Fine1; (3,012,125 million)	0.449	215 minutes
Fine2; (6,022,233 million)	0.451	420 minutes