working fluid

American  

noun

Mechanics.

1. a liquid or gaseous working substance.

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Etymology

Origin of working fluid

First recorded in 1900–05

Example Sentences

In this case the working fluid is air rather than water.

From Economist

In its case the working fluid is water itself, but, like Hydrostor’s system, the pressure head is created by putting the storage vessels underwater—in this case, 100 metres down in Lake Constance, a depth that creates an excess pressure of ten atmospheres.

From Economist

At that time I was experimenting with a new type of refrigeration system that would use water as a working fluid instead of ozone-destroying CFCs.

From BBC

The difference is that instead of starting at room temperature the working fluid ends up there, and starts instead at -196°C, the boiling point of nitrogen.

From Economist

Using the carbon dioxide as a so-called working fluid - used to make the turbine function - it would pass through the system in a loop, to be recycled and used again.

From BBC