Optimum Propulsion System Selection for Long Range Civil Transport Aircraft

Abstract

Fuel economy is a major driving factor behind the recent developments in propulsion system technology for civil transport aircraft. With increase in bypass ratio, specific fuel consumption of a propulsion system decreases with increase in propulsive efficiency. The other major advantage achieved by higher bypass ratio is reduction in noise. Thus, high bypass ratio engines become favorable candidates for future civil transport aircraft. Present study aims at optimum high bypass ratio propulsion system selection for long -range civil transport aircraft. Installation penalties and stringent noise and emission regulations are required to be considered while optimizing the propulsion system. For the present study, a futuristic civil transport aircraft is conceived with a realistic mission. An optimization study is attempted for complete conceptual design of propulsion system for the aircraft. Response surface surrogates (RSM & DACE) are employed in the optimizer. Results presented are based on an in-house built simulation program that integrates aerothermodynamic performance module, engine sizing / weight module, installation module with mission simulator. Work on Noise model is in progress, DACE models, although not reported here, perform better as compared with low order polynomial LSQF models.