THE difficulty encountered while attempting to correlate altitude cooling requirements with sea-level performance led to the resumption of intensive study of the cooling correlation problem by the Wright Aeronautical Corp. early in 1942.
Any correlation of this nature endeavors to establish the relation between engine operating conditions, cylinder-head temperature, pressure drop across the engine, pressure and temperature of the cooling air, cooling air consumption, and heat rejection to the cooling air.
A correlation method based on the density of the air as it leaves the fin passages, which involves the temperature rise and pressure drop of the cooling air, has been developed. A graphical solution of the equations has been evolved which requires a knowledge of only the entering air conditions to enable one to solve for all the above cooling requirements. To demonstrate this method, it has been applied to a specific Wright engine model, based on extensive testing to obtain the necessary constants.