siipipyörä

Siipipyörää is a term used in Finnish engineering to describe a wheel-like rotor that carries a set of blades around a central hub. The blades, shaped for energy exchange with a flowing fluid, enable the device to convert kinetic and pressure energy between a fluid and rotating mechanical energy. Siipipyörä can function as a turbine wheel, extracting energy from a moving fluid, or as an impeller, delivering energy to a fluid.

The design can be classified by the flow type and operating principle. Axial-flow configurations direct the fluid parallel to the wheel axis, while radial-flow configurations move the fluid outward from the axis. In turbomachinery, siipipyörät are often categorized as impulse turbines or reaction turbines, depending on how pressure changes occur within the blade passages.

Common applications include power generation in steam, gas, and hydro turbines, as well as pump impellers used in various fluid-moving systems. Siipipyörät also appear in aircraft propulsion equipment, turbopumps, and other turbomachinery where fluid handling and energy transfer are required. Material selection focuses on strength, fatigue resistance, and corrosion tolerance, with steel alloys, titanium, and composites being typical choices for blades and hubs. Blade geometry, tip-speed, and clearance to housing critically affect efficiency, performance, and operating range.

See also: turbine, impeller, turbomachinery.