US Patent 10336305 Aspirators for producing vacuum using the venturi effect

A Venturi device for producing vacuum from fluids in an engine system has a body defining a Venturi gap separating apart an outlet end of a converging motive section and an inlet end of a diverging discharge section by a lineal distance, and a suction port in fluid communication with the Venturi gap. The converging motive section and the diverging discharge section both gradually, continuously taper toward the Venturi gap, the converging motive section defines a circular-shaped motive inlet and an elliptical- or polygonal-shaped motive outlet, the diverging discharge section defines an elliptical- or polygonal-shaped discharge inlet, and an inner passageway of the converging motive section transitions as a hyperbolic function from the motive inlet to the elliptical- or polygonal-shaped motive outlet.