A device built in a camshaft drive chain sprocket for detecting precise torque fluctuation with minimum
change on the valve drive system dynamical characteristics was developed. Strain gages are placed on thin plate areas in the sprocket disc. The signal from the circuit goes through frequency modulation and is transmitted to demodulation circuit via coil antennas. By this arrangement, almost perfect linearity was observed in the relationship of the output voltage and the applied torque. Torque fluctuation measured with this device on a model cylinder head driven by a variable speed motor showed good correlation with simulation results.
External or integrated water-cooled exhaust manifolds are mentioned to be favourable for the overall engine behaviour on diesel and gasoline engines. To validate this potential, an analytical study has been conducted. A diesel and a gasoline engine model were built-up in GT-SUITE to assess the influence of water-cooled exhaust manifolds at full load. These engine models have been combined with VeLoDyn - a tool from IAV for vehicle simulation considering heat fluxes between engine and vehicle cooling system - to show the potential of the different designs in a driving cycle, including the catalyst heating up phase.
This paper reports the electrolysis of aqueous methanol for hydrogen production in a proton exchange membrane electrolyzer with a novel porous flow field made of sintered spherical metal powder. Results show that the use of porous flow field has a significant improvement in hydrogen production performance compared to a conventional groove flow field. This could be attributed to an increase in effective electrode area by using the porous material which enables the flow field to supply reactant evenly to the electrode and removes products smoothly. Influences of the operating conditions such as methanol concentration and cell temperature on hydrogen production are also discussed.
This study investigates the characteristics of combustion noise generation in a diesel engine under running condition using wavelet transformation and transient combustion-noise-generation model. The results show that combustion noise largely contributed to the total engine noise in the early stage of the expansion stroke. Maximum combustion impact energy had a predominant effect on maximum combustion noise power and therefore on maximum engine noise power for each cycle. The combustion noise power exponentially decayed with time. The duration of combustion noise depends mainly on the maximum combustion noise power, which is controlled by the maximum combustion impact energy and transmission-radiation rate.