Chapter 9, Problem 9.12Q

Ex. HW. A vertical glass tube, 2cm ID & 5m long in heated uniformly over its length. The water enter at (200-204 C) & 68.9 bar calculated the pressure drop if the flowrate 0.15 Kg/s & the power applied as a heat to the fluid is 100KW using the homogeneous model. Given that enthalpy at inlet temp.=0.87MJ/Kg, enthalpy saturation temp (285C)=1.26 MJ/Kg and μl=0.972*10-4 Ns/m2, μG=2.89*10-5 Ns/m2, UG=2.515*10-2m3/Kg and the change in UG over range of pressure=-4.45*10-4m3/Kg/bar.

4. An experimental test rig is used to examine two-phase flow regimes in horizontal pipelines. A particular experiment involved uses air and water at a temperature of 25°C, which flow through a horizontal glass tube with an internal diameter of 25.4 mm and a length of 40 m. Water is admitted at a controlled rate of 0.026 kgs at one end and air at a rate of 5 x 104 kgs in the same direction. The density of water is 1000 kgm³, and the density of air is 1.2 kgm. Determine the mass flow rate, the mean density, gas void fraction, and the superficial velocities of the air and water. Answer: 0.02605 kgs 1, 61.1 kgm³, 0.94, 0.822 ms-1, 0.051 ms-1

and the viscosity of the water is 1.24 × 104 Nsm 2. Answer: Slug flow 1. Determine the range of mean density of a mixture of air in a 50:50 oil-water liquid phase across a range of gas void fractions. The den- sity of oil is 900 kgm³, water is 1000 kgm³, and gas is 10 kgm³.