• Using dimensionless parameters, on log–log graph. Explain, what a log–log graph is. When and why it is required?
• Use a standard curve-fitting technique to determine a general equation for ΔP?
• What are the limits of applicability of the equation?
• Write your comments

The pressure drop across a sudden expansion pipe the diameter changes from d to D through which a liquid is flowing as shown in figure below. Diameter = d AP = f( d, D, V, p) density = p Diameter = D The pressure drop AP which develops across the expansion is a function of d and D as well as the velocity V in smaller section of pipe and the fluid density p. Determine a suitable set of dimensionless parameters by using variable reduction method? Also why would it be incorrect to include the velocity in the bigger pipe as an additional variable? D (mm) (bar) 75 mm 0.05 100 mm 0.2 125 mm 0.45 150 0.6