Amodel test of a tractor-trailer rig is performed in a wind tunnel. the drag force, fd, is found to depend on the frontal area, a, wind speed, v, air density, r, and air viscosity, µ. the model scale is 1: 4 (e. g., 1 m in the model is equivalent to 4 m in the prototype), frontal area of the model is a = 0.625 m2 . a. obtain a set of dimensionless parameters suitable to characterize the model test results

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa. s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)