Certain embodiments herein relate to configurations for reducing the flow area for fluids traveling through a Vortex flowmeter. Such configurations may establish a minimum required Reynolds number consistent with optimized performance of the Vortex flowmeter. Various configurations for achieving optimized performance may include inserting one or more segments or a streamlined, torpedo-shaped body into a bore of a meter body of the Vortex flowmeter to block a certain cross-sectional area of the bore. By reducing the cross-sectional area of the bore, the Reynolds number of fluids may be increased to the optimized level. Another configuration may include reducing the diameter of the bore of the meter body. Any of these configurations may be implemented to achieve a desired Reynolds number, and hence, optimized performance. Certain embodiments herein also relate to determining or calculating precise or near precise sizes for segment insertions, torpedo body diameters, and diameters of the meter body.