A numerical study of an orifice flowmeter

An orifice flowmeter used for the measurement of the extensional viscosity has been numerically analyzed by means of the finite volume method. A good agreement with experimental data reported previously in the literature was found. Flow fields, in particular the streamline maps, showed that an excess of pressure is required for removing or minimizing the effect of the flow structures generated downstream the orifice such as vortices and dead zones when using abrupt contractions (8:1). For that reason, a new die geometry based on a semihyperbolic profile was proposed and successfully tested with Newtonian and non-Newtonian fluids resulting in a better performance orifice flowmeter.

► An orifice flowmeter has been numerically analyzed by means of the finite volume method.
► Flow fields showed the formation of vortexing downstream the orifice.
► A new die geometry based on a semihyperbolic profile has been proposed and successfully tested.