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Technological and commercial development of vehicles specifically conceived for urban use would certainly be a crucial aspect in making mobility sustainable in urban contexts thanks to their limited in size and low fuel consumption and emissions. Hybrid drive trains are particularly suited to this purpose: if properly designed, very small-sized thermal engines can give all the energy and power required for the application, also making pure electric driving possible when required. The authors are involved since a decade in proposing new low-cost solutions to address this market sector. Market itself explored these possibilities and nowadays offers some BEV solutions in this market share, but it is still lacking in proposing solutions for a parallel full hybrid drive. The main reason must be searched in the complexity of normally applied parallel-hybrid propulsion systems which is not compatible with the limited costs of the application.

The objective proposed by EU to reduce by about 4%/year CO2 emission of internal combustion engines for the next years up to 2030, requires to increase the engine efficiency and accordingly improving the technology. In this framework, hybrid powertrains can have the possibility of a deep market penetration since they may recover energy during brake, allow the engine to operate in better efficiency conditions and with less transients, Moreover, they can recover a large amount of energy lost through the exhaust and use it to reduce fuel consumption. This paper concerns the modification of a conventional two in-line cylinders Diesel engine (440 cm3) adding a variable geometry turbine (VGT) coupled with a generator. The turbine is used to recover exhaust gas energy that otherwise would be lost. The generator, connected to the turbo shaft, converts mechanical energy into electrical energy and is used to charge the vehicle battery or the auxiliaries.

Within the “Industria 2015” Italian framework program, the HI-ZEV project has the aim to develop two high performance vehicles: one full electric and one hybrid. This paper deals with the electric energy storage (EES) design and testing of the hybrid vehicle. A model of the storage system has been developed, simulating each cell like an electric generator with more RC circuits in series. To take account of the heat transfer, a forced convection model has been used with the air speed proportional to the vehicle speed. The model had two calibration steps: the first has determined the electrical parameters of the model (open voltage circuit, internal resistances and capacitors); the second to calibrate the heat transfer model. The first calibration has been made on a climatic chamber at 23 °C discharging one single module with different constant currents from 5C (5 times the nominal capacity) to 25C and charging with currents in the range from 1C to 5C.

The experimental measurement of the energy consumption and efficiency of Battery Electric Vehicles (BEVs) are key topics to determine their usability and performance in real-world conditions. This paper aims to present the results of a test campaign carried out on a BEV, representative of the most common technology available today on the market. The vehicle is a 5-seat car, equipped with an 80 kW synchronous electric motor powered by a 24 kWh Li-Ion battery. The description and discussion of the experimental results is split into 2 parts: Part 1 focuses on laboratory tests, whereas Part 2 focuses on the on-road tests. As far as on-road tests are concerned, the vehicle has been tested over three different on-road routes, ranging from 60 to 90 km each, with a driving time ranging from approximately one and half to two and half hours.

The experimental measurement of the energy consumption and efficiency of Battery Electric Vehicles (BEVs) are key topics to determine their usability and performance in real-world conditions. This paper aims to present the results of a test campaign carried out on a BEV, representative of the most common technology available today on the market. The vehicle is a 5-seat car, equipped with an 80 kW synchronous electric motor powered by a 24 kWh Li-Ion battery. The description and discussion of the experimental results is split into 2 parts: Part 1 focuses on laboratory tests, whereas Part 2 focuses on the on-road tests. As far as the laboratory tests are concerned, the vehicle has been tested over three different driving cycles (i.e. NEDC, WLTC and WMTC) at two different ambient temperatures (namely +25 °C and −7 °C), with and without the use of the cabin heating, ventilation and air-conditioning system.

The adoption of composed (hybrid) lead acid battery-supercapacitor (SC) storage systems is able to improve performances (availability, durability, range) of an electric microcar. As a matter of fact, the supercapacitors extend the operation time not only by improving the energy efficiency (thanks to a higher contribution of regenerative braking), but also by reducing the power down caused by voltage drop at higher discharge rates. The integration of battery with supercapacitors requires careful analysis and calculation of the relationship between battery peak power and size of the SC bank, needed to have a balanced composition of the hybrid storage system. For this purpose, the optimization process, summarized here, is based on the combination of a conventional lead-acid battery and a commercial SC, with the vehicle running the ECE15 driving cycle.

This paper reports the results of experimental tests performed at ENEA (Italian National Agency for New Technologies, Environment and Sustainable Development) in its “Casaccia” Energy Research Center to evaluate the energetic and environmental performances of a Heavy-Duty Compressed Natural Gas (HD CNG) engine fuelled with a hydrogen-methane blend of 15% in volume. A lean burn Mercedes 906 LAG engine has been optimized properly calibrating ECU engine maps regarding both ignition advance and air to fuel ratio (AFR). It was therefore possible to correct ignition advance to take into account the faster combustion speed given by the hydrogen content of the fuel mixture. Equivalence ratio (Lambda) has instead been modified in order to minimize the NOx emissions. All the tests were performed on a steady engine test-bed focusing the attention on the most important parts of the engine maps.

Computer software, which simulates the thermodynamic and gas dynamic of internal combustion engines, are used extensively during design and development process. This paper analyzes the 1D boundary multi-pipe junctions calculations using the Method of Characteristics (MOC). Sonic flows can be encountered in the exhaust manifolds of internal combustion engines (especially racing engines) and in the model a check if the flow is sonic or not have been made. Flows with more than one manifold have flow toward the junction, need an equivalent “Datum” manifold, with an airflow as the sum of all flows, an averaged area and stagnation enthalpy has been defined in order to calculate the pressure loss when crossing the junction. The pressure loss terms have been calculated as function of the flow-ratio of the gas flowing to the manifold to the total incoming flow and the pipe angle.

European Type approval procedure defines a synthetic driving cycle (the NEDC) over which one vehicle per type has to be tested. Euro 1, 2, 3, 4 and 5 differ (beside vehicle preconditioning and warm-up procedures introduced since Euro 3) only because limits for the different pollutants have been progressively lowered. This paper analyses through a number of experimental tests on spark-ignition cars, a hybrid and a conventional vehicle, the driving conditions responsible for most of the emissions and assesses how such conditions are reproduced by the type approval test. The engine conditions mostly responsible for emissions are: warm-up phase, full loads and transients. Only the warm-up is well covered by the NEDC for vehicles with more than 35 kW/ton power-weight ratio.

The actual type approval procedure of vehicles, based on a fixed driving cycle for all the vehicles (NEDC), is not representative of their real on-road usage: the driving style and its influence on consumption and emissions cannot be neglected. The on-road impact of vehicles on their real use is not known and it is difficult to measure (the PEMS are expensive, have big volume and mass and need continuous maintenance); the objective of this work is to develop a methodology to calculate in real time the energy and environmental impact of spark ignition vehicles, using the onboard sensors of the vehicle and emissions models to calculate them. An onboard instrumentation able to communicate with the electronic system of the vehicle (OBD/CAN) was developed to collect all the sensor data installed on a vehicle: those values are used as input values to the emissions models of CO₂, CO, HC and NOx developed in the present work.

Passenger vehicles are one of the most significant source of pollution in the cities. The emissions production of a vehicle is strictly dependent on how the vehicle is used. This paper has the objective to characterize a Euro IV vehicle so to understand in depth the behavior in its real usage on road in terms of fuel consumption and emissions. An Honda Civic 2.0 Euro4 vehicle has been tested and the experimental results are reported. The experiments have been carried out by means of two tools: a OBD2 interface to connect a laptop PC to the vehicle for collecting engine parameters (Alessandrini et al. 2006) and the HORIBA OBS1300 equipment to measure CO, NOx, HC emissions and the exhaust gas flow, pressure and temperature. Three types of experimental tests have been made: a set of them on a dynamometer chassis and a part on road.