turbomachine

A turbomachine is a mechanical device that transfers energy between a rotor and a fluid. It can either extract energy from the fluid, producing shaft power (turbines), or add energy to the fluid, increasing its pressure or flow (compressors and pumps). The fluid can be a gas or a liquid.

Turbomachines are broadly classified into turbines, compressors, and pumps. They are further categorized by flow type: axial flow (blades aligned with the axis), radial or centrifugal (flow outward from the axis), and mixed-flow. Some devices combine functions, such as turbocompressors or pump-turbines.

Operation: The rotor carries blades that impart or extract momentum from the fluid. In turbines, fluid energy is converted into shaft power. In compressors and pumps, mechanical power raises the fluid pressure and/or drives flow. The interaction is described by energy transfer relations and velocity triangles.

Applications: energy generation using steam or gas turbines; aircraft propulsion and power systems; refrigeration and air conditioning; industrial pumps and water supply; turbomachinery in chemical processing and power plants.

Performance and design: Key metrics include efficiency, flow rate, head or pressure rise, and power. Design concerns include mechanical reliability, bearing and seal integrity, cooling, and vibration. Cavitation can occur in pumps; surge, stall, or surge in compressors; and noise and emissions in engines.

History: Turbomachines have evolved from early water wheels and steam-driven devices to modern gas and steam turbines, centrifugal compressors, and high-speed turbomachinery used in aviation and power generation.