The Potential of The Co-Rotating Compressor in Gas Turbine Applications

Abstract

The concept of co-rotating axial compressor was conceived primarily as a means of overcoming the inherent rotational speed mismatch between a fan and its driving turbine in moderate to high bypass ratio turbo-fan engines. In essence, the arrangement serves as a torque converter or "aerodynamic gear box" transferring a fraction of the energy supplied by the high pressure turbine to the compressor casing shaft via the co-rotating casing. Thus, considerable modifications in performance of gas turbine engines can be achieved. The present work examines the potential of exploiting the co-rotating compressor concept in major applications of gas turbines, among which are; turbo-fan, turbo-jet, turbo-propeller, turbo-shaft and basic industrial gas turbine engines. The paper formulates torque and power constraints for engines which show feasibility of utilizing a co-rotating compressor. It also formulates speed relationships of components. Basic analyses are carried out, critical parameters are indicated, and characteristics of performance of engine components are discussed, with due consideration of the likelihood of load variation