mixedflow

Mixedflow is a term used in fluid mechanics and turbomachinery to describe flow and machine configurations in which the fluid velocity has appreciable components in both axial and radial directions. It denotes devices and flows that operate between axial-flow and radial-flow paradigms, offering a compromise between high flow capacity and moderate head. In the context of pumps, a mixed-flow pump uses an impeller whose blades generate a velocity triangle with both axial and radial components, yielding higher discharge than pure axial pumps and higher head than typical axial devices, while retaining better efficiency at large flows than purely centrifugal radial designs.

In turbines, mixed-flow machines blend axial and radial flow paths within the runner, enabling operation over a mid-range head-to-flow ratio and often smaller size compared with purely radial designs at the same power.

Design and performance considerations include blade shape, inlet and outlet flow angles, hub-to-shroud geometry, and operating range; efficiency, cavitation resistance, and net positive suction head are typical concerns. Since mixed-flow devices rely on a balance of axial and radial components, computational fluid dynamics and experimental testing are common for optimizing performance.

Applications include water supply pumps, irrigation, drainage, and industrial process systems, as well as small-scale hydropower where medium head and high flow are present.