Fluid Mechanics
A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 10³ VOM + 10.94 x 10⁶ V²OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is

16 mm/s
12 mm/s
24 mm/s
28 mm/s

ANSWER DOWNLOAD EXAMIANS APP

Fluid Mechanics
The Prandtl mixing length is

Zero at the pipe wall and is a universal constant
Independent of radial distance from the pipe axis
Independent of the shear stress
Useful for computing laminar flow problems

ANSWER DOWNLOAD EXAMIANS APP