The Compression Ratio Calculator can help to determine how to shift the location of a piston in order to achieve a given Compression Ratio, and can be used to confirm a given setup. This utility is valid for a chamber that contains a crank-angle–based motion control assigned to the moving boundary condition.
Use the menu command to open the utility.
The utility uses the No-Hydro CR Calculation method, which runs a single time step at two time points α and β; these are the points when the crank angles are at TDC and BDC. This method uses the solver mesh generation to get an accurate calculation of the in-cylinder volume at each time point.