Chances for Alternative Drivetrains and (Types of) Energy for Le Mans

Authors

V. Beaumesnil, Automobile Club de l’Ouest, Le Mans; B. Niclot, FIA, Paris; Dr. W. Warnecke, Shell, Hamburg

Year

2017

Print Info

Fortschritt-Berichte VDI, Series 12, No 802

Summary

Over the last 100 years race cars have been powered with combustion engines, and fuelled with gasoline or diesel, and progressing electrification. The challenges in Future Mobility will be driven by the global and local emissions caused, but also by energy resources available and fuels as energy carrier producible. The World Endurance Championship (WEC) Race Series with it’s Le Mans 24h race has the proven spirit to drive innovation in vehicles. The openness for innovation has been demonstrated in recent years through gasoline and diesel engines competing with each other, and with different levels of hybridization. The WECs intention is to support new fuels and new drivetrain concepts, driven by ecology (emission) and efficiency improvements required and to develop a testing ground for new vehicle concepts eventually entering the market. Two routes are seen as options for endurance applications: One is to further improve conventional combustion engines (ICE) using advanced combustion processes and reducing emission output with beneficial sustainability, e.g. the use biofuels, such as bio-methane (which is Le Mans’ “Pit 56” innovation driver concept for 2017). The other route is to extend the use of electrified systems, moving up from ICE Hybrids with part time full electric drive only, to full electric operation only through Battery Electric Vehicles (BEV) or Fuel Cell Electric Vehicles (FCEV, using Hydrogen). BEVs using today’s technology options face major challenges for endurance racing (or long haul driven distances) due to energy density and energy storage issues in the vehicle and the required recharging time – apart from weight and volume of the batteries required. Further detailed evaluation would be required to challenge whether BEVs could be successful to race in WEC endurance races. Therefore, FCEVs using hydrogen maybe the best remaining option for emission free motorsport and could compete with conventional ICE hybrid drivetrains in endurance races. This paper will concentrate on the evaluation of FCEVs using H2 and will ask how competitive such a concept could be against gasoline or diesel powered hybrids in Le Mans Prototype 1 (LMP1) race cars. The discussion will be based on simulation models, which have been developed by the FIA together with the Automobile Club de l’Ouest, ACO, and which allow us to compare a FCEV LMP1 with a combustion engine Hybrid LMP1 with the aim to determine where the challenges are and which options could ensure competitiveness. The goal is to identify technical challenges of fuel cell drivetrain efficiency, analyze the need for cooling (and its influence on aerodynamics), evaluate size and weight of the drivetrain taking into account the condition of hydrogen (high pressure or cryogenic liquid H2), the tank system and the refuelling options required. This paper will discuss the challenges, options and areas for improvement of FCEV race cars and aims to discuss these findings as input for future WEC race options.