Multi objective Optimization of Conceptual Rotorcraft Powerplants: Trade off Between Rotorcraft Fuel Efficiency and Environmental Impact

Abstract

This paper aims to present an integrated rotorcraft conceptual design and analysis framework, deployed for the multidisciplinary design and optimization of regenerative powerplant configurations in terms of rotorcraft operational and environmental performance. The proposed framework comprises a widerange of individual modeling theories applicable to rotorcraft flight dynamics, gas turbine engine performance, and weight estimation as well as a novel physicsbased, stirred reactor model for the rapid estimation of gas turbine gaseous emissions. A multiobjective particle swarm optimizer (mPSO) is coupled with the aforementioned integrated rotorcraft multidisciplinary design framework. The combined approach is applied to conduct multidisciplinary design and optimization of a reference twin engine light civil rotorcraft modeled after the AirbusHelicopters Bo105 helicopter, operating on representative mission scenario. Through the implementation of a multiobjective optimization study, Pareto front models have been acquired, quantifying the optimum interrelationship between the mission fuel consumption and gaseous emissions for the representative rotorcraft and a variety of engine configurations. The acquired optimum engine configurations are subsequently deployed for the design of conceptual rotorcraft regenerative engines, targeting improved mission fuel economy, enhanced payload range capability, as well as improvements in the rotorcraft overall environmental impact. The proposed methodology essentially constitutes an enabler in terms of focusing the multidisciplinary design and optimization of rotorcraft powerplants within realistic, threedimensional operations and toward the realization of their associated design tradeoffs at mission level.