An isentropic process is an idealized thermodynamic process that is adiabatic. A process during which the entropy remains constant is called an isentropic process. Use the below calculator and find the value of Isentropic flow relation between pressure and total Pressure. This isentropic flow relation calculator works based on the specific heat ratio, density and total density of an isentropic flow can be calculated using this calculator. An adiabatic process is a one where there is no transfer of heat or matter and the process is reversible.