Propulsion systems trends

Propulsion systems as they exist today and some trends that are anticipated for aircraft that might be flying in the f9808s are presented.The number one trend for commercial engines is to quiet them to a level no louder than the normal background noise level of the environment in which they will operate, Ih.1 military engines that are not so severely noise constrained, the possibility of stoichiometric gas turbine engines is within reach and will probably come into being whenever a military requirement provides sufficient motivation to develop such an engine.Very high bypass ratio engines are likely to find application in V/STOL aircraft while the evolution of variable geometry inlets and exhaust nozzles receives its impetus from supersonic airplanes.Both supersonic and V/STOL aircraft are prime candidates for digital computer control systems that will integrate the control 0% the propulsion system, the airplane, and its flight path, Multimode propulsion systems and supersonic combustion ramjets may one day be utilized in hypersonic cruise and boost aircraft while the first nuclear propelled aircraft most likely will fly at subsonic speeds, * Head of Propulsion Section in Advanced Systems Division.