What does ohp mean? What word abbreviation?

Two meanings:

The meaning of OHP projection film (copying with a single-page hand tray) projector (OHP).

oscillating heat pipe (OHP), also known as pulsating heat pipe, self-excited oscillating flow heat pipe, curved capillary heat pipe, etc., is a new and unique heat transfer element based on and superior to ordinary heat pipes, which was proposed by Akachi of Japan in the early 199s.

Extended information:

Working principle

A curved capillary tube pumped into vacuum in a tube is filled with a certain amount of working medium, which forms a plug-like flow of steam and liquid randomly in the pipeline under the action of temperature difference between the cold and hot ends and surface tension. In this way, due to the pressure difference between the two ends and the pressure imbalance between adjacent tubes,

The working medium oscillates between the evaporation end and the condensation end, that is, the heat transfer is realized through the phase change and the oscillation of the liquid plug. The heat transfer phenomenon integrates boiling, evaporation, condensation and pulse oscillation. These physical processes are not isolated and simply superimposed, but an organic interactive whole process. So far, people have preliminarily understood its operating mechanism.