critical pressure [`krid·ǝ·kǝl `presh·ǝr] FLUID MECHANICS For a nozzle whose cross section at each point is such that a fluid in isentropic flow just fills it, the pressure at the section of minimum area of the nozzle; if the nozzle is cut off at this point with no diverging section, decrease in the discharge pressure below the critical pressure (at constant admission pressure) does not result in increased flow. THERMODYNAMICS The pressure of the liquid-vapor critical point. |