NVH Challenges and Improvements Implemented in Ford H ² RV: An HEV Propelled with a Supercharged Hydrogen Internal Combustion Engine 2004-01-0061

Ford's H²RV (Hydrogen Hybrid Research Vehicle) uses a Hydrogen fueled Internal Combustion Engine. This engine has a higher compression ratio and a faster fuel-burning rate compared to a conventional gasoline engine. The conventional flywheel is replaced with an electric motor in the hybrid powertrain, which causes higher crankshaft torsionals and is a major NVH source. The engine has a centrifugal supercharger mounted on its front-end dress, which is a big source of NVH. Fans are used to cool the high voltage batteries and to provide ventilation of H₂ in the case of a leakage. The body sheet metal has several holes for passive H₂ ventilation, battery cooling, plumbing lines, and harness routing. Underhood hardware, due to the hybrid transmission and the H₂ ICE, created major packaging challenges for the intake and FEAD NVH. The exhaust muffler volume was limited due to the installation of high voltage batteries and underbody H₂ fuel tanks. The hardware changes in the vehicle affected overall NVH. In this paper, the authors discuss these challenges and actions implemented to improve the overall NVH.