Question

Fluid Mechanics:
based on pressure losses in pipes experiment

1.Discuss the reasons and difference between f values obtained experimentally and analytically using moody chart.

2.Comment on the reasons for variation of loss coefficients among fittings.

3.What would affect the accuracy of K and f factors.

Answer 1

1. The possible reason for the difference in experimental and theoretical value of f is due to difference in ideal conditions for formulation of Moody chart and real conditions of the experiment. Due to dynamic change in physical parameters of the experiments, the actual value of f based on pressure loss is different from that of Moody chart value.

2. Loss coefficient among fittings are derived from the losses that we obtain at the fitting. Generally, this is a theoretical value, and real value depends on the type of flow conditions, regime of flow, surface roughness and bend angle. All such factors contribute to actual loss coefficient, whereas not all factors are considered for theoretical loss coeffcoeffic

3. K and f accuracy would mainly affected by mapping the ideal conditions for experiments to the actual one.