Assessing Alternative Fuels for Helicopter Operation

At present, nearly 100% of aviation fuel is derived from petroleum using conventional and well known refining technology. However, the fluctuations of the fuel price and the vulnerability of crude oil sources have increased the interest of the aviation industry in alternate energy sources. The motivation of this interest is actually twofold: firstly, alternative fuels will help to stabilize price fluctuations by relieving the worldwide demand for conventional fuel. Secondly, alternative fuels could provide environmental benefits including a substantial reduction of emitted CO₂ over the fuel life cycle. Thus, the ideal alternative fuel will fulfill both requirements: relieve the demand for fuels derived from crude oil and significantly reduce CO₂ emissions. In the present paper, the effects of various alternative fuels on the operation of a medium transport/utility helicopter are investigated using performance models of the helicopter and its associated turboshaft engine. These models are developed in an object-oriented simulation environment that allows a direct mechanical connection to be established between them in order to create an integrated model. Considering the case of a typical mission for the specific helicopter/engine combination, a comparative evaluation of conventional and alternative fuels is then carried out and performance results are presented at both engine and helicopter levels.