H glossary entries

An H-bridge is a power switching circuit with four controlled switches arranged so a load can be driven with either voltage polarity.

Hardness is a material's resistance to localized plastic deformation, usually measured by indentation, scratching, or rebound methods.

Harmonic distortion is waveform distortion produced by harmonic components at integer multiples of the fundamental frequency.

Heat duty is the rate of heat transfer required, supplied, removed, recovered, or rejected across a defined boundary.

A heat exchanger is a device that transfers thermal energy between fluid streams or between a fluid and a solid surface.

Heat flux is heat-transfer rate divided by the area through which heat crosses, usually expressed in watts per square metre.

A hoist is a mechanical lifting device used to raise, lower, or hold a suspended load by means of chain, wire rope, drum, sheaves, gears, brakes, and a drive system.

Homogenization is a multiscale modelling method that replaces a heterogeneous material or structure with an equivalent continuum having effective properties.

Hydraulics is the engineering study and application of liquids at rest or in motion, especially where pressure and flow are used to transmit energy or control forces.

Hydrostatic pressure is the pressure at a point in a stationary fluid due to the weight of the fluid column above it.

Hysteresis is path-dependent behaviour where the output of a system depends on previous states, not only on the current input.