The pressure rise, ∆p = p2 – p1, across the abrupt expansion of Fig. P7.32 through which a liquid is flowing can be expressed as
where A1 and A2 are the upstream and downstream cross-sectional areas, respectively, ρ is the fluid density, and V1 is the upstream velocity. Some experimental data obtained with A2 = 1.25 ft2 , V1 = 5.00 ft/s, and using water with ρ = 1.94 slugs/ft3 are given in the following table:
Plot the results of these tests using suitable dimensionless parameters. With the aid of a standard curve fitting program determine a general equation for ∆p and use this equation to predict ∆p for water flowing through an abrupt expansion with an area ratio A1/A2 = 0.35 at a velocity V1 = 3.75 ft/s.