Automotive Science and Engineering

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Driving cycle is used to assess fuel consumption, pollutant emissions and performance of the vehicle. The aim of this paper is to extract the driving cycle for refuse collection truck and estimate its braking energy. For this purpose, after selecting the target truck and geographic area, the equipment needed to measure the required variables were prepared and mounted on the truck. Then, the actual data were collected from the performance of the target Truck while performing its mission. Since the amount of braking energy depends on the speed, truck mass and road grade, the speed of the vehicle is measured simultaneously with the truck mass and road grade. The collected data are then processed and subdivided into micro-trips. The micro-trips are clustered according to the number of state spaces using the K-Means algorithm. Next, the representative micro trips are selected from within the clusters and the final driving cycle is generated. The representative driving cycle shows that the truck speed is zero at 47% of the working time. Finally, the amount of braking power and accumulative braking energy in the driving cycle is calculated.

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In this article, the procedure of series hybridizing is fulfilled on the O457 city bus that is produced in Irankhodro Diesel Company. For simulation validation the bus with base diesel engine is simulated in European and Tehran compound urban–highway driving cycle and fuel consumption results compared. First the ECE_EUDC_LOW driving cycle  simulation results compared with the results of the advisor software that was some difference between two software results. For deep validation bus with base engine was simulated in Tehran driving cycle and fuel consumption calculated 53.26 Lit/100Km that was near actual value that is 59.48 Lit/100Km. After verification, a bus with series hybrid electric-diesel powertrain was designed and simulated in the European and Tehran driving cycle. Simulation results and experimental data’s shown that the series hybrid electric-diesel bus fuel consumption reduction in ‌the ECE_EUDC_LOW driving cycle, is 30% and in Tehran driving cycle is 39% less in comparison to base power train that is base diesel engine.

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This paper introduces a novel powertrain system composed of a liquid ammonia internal combustion engine, a dissociation and separation unit, and a PEM fuel cell system developed for vehicular applications. Using a carbon-free fuel for the ICE and producing hydrogen on board for PEMFC use significantly enhance this novel systemchr('39')s environmental effects. The thermodynamic analyses are conducted using EES and MATLAB software. The results show that while this hybrid powertrain system produces 120 kW output power, energy and exergy efficiencies are 45.2% and 43.1%, respectively. The overall exergy destruction rate of the system becomes 237.4 kW.The fuel consumption, engine speed, and battery state of charge (SoC) analyses are calculated using three driving cycles. These vehicles consume 7.9, 5.7, and 7.7 liters of liquid ammonia per 100 km in FTP-75, NEDC, and HWFET driving cycles, respectively. The battery state of charge differentiation in these three cycles shows the practicality of this novel powertrain system specially in inner-city driving cycles as the battery does not confront any intense decline of SOC to the minimum level. HWFET results show the great dependence of the vehicle on ICE and low PEM fuel cell function, which results in releasing decomposed hydrogen to the environment.