In 1989 Rudolph Draaisma worked for a company Rotocold Technology Ltd (RTL, no longer existing) that at the time did research on refrigeration technology, based on rotary vane machines. It was then that he came up with the Compex cycle theory. Experiments were made at RTL but they couldn’t make it work. Some piece was missing. Over the years, having acquired more knowledge in the field of thermodynamics, he believed that he had found the answer in what he named as Supertropic expansion.
The definition of Supertropic expansion, in Mr. Draaisma’s own words, is: an adiabatic, non-isentropic expansion