Hi everyone,I am hoping to discuss the value of a design. The original idea was intended to receive the thermal energy from the exhaust from an internal combustion (IC) engine and produce additional power. The working principle is much like a Stirling engine except that instead of a regenerator it relies on a phase change to create a substantial efficiency advantage over the Stirling design. Water as an example will expand about 1600 times its volume when boiled. Water vapor, nitrogen and all other gases change at a linear rate when the temperature changes. Therefore a chamber with a very small quantity of water at its phase change equilibrium will require a fraction of the energy required to produce the same pressure change as is common in a Stirling engine. The engine is a closed cylinder with many sliding vanes creating chambers that increase and decrease in volume. Other than a drive shaft and perhaps a valve stem to add a liquid and pressurize the unit there is no entrance or exit for the working fluid (it is not a water wheel). The external radius will have attached heat exchange surfaces or insulation as is required to handle the intended thermal exchange. The activity in the circular cycle of each chamber can be visualized when separated into quadrants (red outline), including two areas where the chamber volume changes very little, one large (3) and one small (1) and two where the chamber volume is either increasing (2) or decreasing (4) when the rotor is turned (clockwise). Before starting a cylinder allowing the conduction transfer of thermal energy though the circular wall of the outside circumference is closed. Confined in the formed chambers of the closed cylinder is a specified pressure of gas and a less than 3% by volume quantity of working phase change liquid. A gas such as helium is specified for its heat transfer coefficient and the liquid is specified for its boiling point at the pressure and temperature range anticipated. The cycle starts by transferring thermal energy into the chambers adjacent to the quadrant having the small average chamber volume (1). The transferred thermal energy both expands the gas contained and causes the liquid contained to boil (change phase), increasing the pressure. The increased pressure pushes the chamber through the next quadrant, where the volume is increasing, (2) turning the rotor. As each chamber moves though the quadrant having the large average volume (3), the thermal energy is transferred out, causing the gas to contract and the boiled vapor to condensate, reducing the pressure contained. The reduced pressure will now cause the described chambers to move through the quadrant having a declining volume, (4) then back to the start, carrying with it the quantity of condensate ready to be expanded to vapor again. Thank you in advance for contributing to this idea.