Q 10.13 Glycerine flows steadily through a horizontal tube of length 1.5 m and radius 1.0 cm. If the amount of glycerine collected per second at one end is 4.0 × 10-3 kg s-1 , what is the pressure difference between the two ends of the tube ? (Density of glycerine = 1.3 × 103 kg m-3 and viscosity of glycerine = 0.83 Pa s). [You may also like to check if the assumption of laminar flow in the tube is correct].
The volumetric flow rate of glycerine flow would be given by
The viscosity of glycerine is
Assuming Laminar flow for a tube of radius r, length l, having pressure difference P across its ends a fluid with viscosity would flow through it with a volumetric rate of
Reynolds number is given by
Since Reynolds Number is coming out to be 0.3 our Assumption of laminar flow was correct.