ABSTRACT
Experiments were conducted using a simple (two plastic funnels), easily built (in a few hours) and inexpensive (costing about the equivalent of a meal at Red Lobster) venturi meter. Three modified Bernoulli balances were used to determine mass flows and permanent pressure loss for the flowmeter. The mass flow rate from the Bernoulli balance calculation gave a mass flow rate that was 112% of the experimental flow rate, yielding a discharge coefficient of 0.89. Small, well-constructed venturi meters have discharge coefficients of about 0.98. Since this homemade flowmeter was not very well constructed, the low discharge coefficient is understandable. The permanent pressure loss was correlated using a minor loss coefficient applied to the velocity head in the venturi throat. The minor loss coefficient was 0.29, which compares with the minor loss coefficient of a well-designed venturi meter of about 0.1. This inexpensive flowmeter is ideal for teaching the use of Bernoulli balances to model fluid systems.
