Flowmeters are disclosed herein that include one or more flow path features for improving the measurement accuracy or other aspects of the flowmeter. In some embodiments, the flowmeter includes a measurement section having a non-circular transverse cross-section in which one or more sensors for measuring flow are disposed. The non-circular measurement section can reduce distortion of ultrasonic waves, facilitate chordal measurements with flush-mounted transducers, and reduce the propagation distance between paired transducers. In some embodiments, the flowmeter includes a conditioning section with diametrically opposed longitudinal rib protrusions. The protrusions can reduce swirling flow, direct liquid components of a multi-phase flow towards the sidewalls of the flow path, and guide ballistic particles through the center of the flow path away from sensitive measurement devices.