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This paper examines the possible electric energy collected by the photovoltaic (PV) modules installed on the roof of the bus. The tests were carried out for Mercedes Conecto LF12 buses equipped with CI engine meeting the standards of Euro 5. The research was conducted in the urban contexts/operation. Detailed results of the measurements such as fuel consumption, electric energy consumption, engine speed and vehicle speed are shown. Additional measurements included: the quantity of solar energy coming from the roof of the moving vehicle and electric energy generated from the photovoltaic modules installed. The study was conducted on a city bus taking different routes in the city of Lublin in Eastern Poland. The research bus was supplied with photovoltaic modules and a measurement system.

The article presents convective heat transfer phenomenon by analytically and empirically taken data and CFD based model analysis. 1000 hp ASz-62IR aircraft radial engine is the object of research. This engine is being continuously operated on M18 Dromader and AN-2 aircraft. To recount heat oriented phenomena a three-dimensional CFD model was developed that accounts circumfluent flow around cylinder and cylinder head engine surfaces. The geometry includes M18 Dromader frontal airframe elements to account their influence on cooling air flow. The simulation has been conducted as a steady-state flow. Geometry and setup specific swirls and backflows were observed that increase cylinder and cylinder head rear side heat transfer coefficients. Flow along cooling fins was analysed, connecting their heat transfer coefficient dependency. Results show that local air velocity has big influence on heat flux passed by fin walls.

The article presents results of the 3D-CFD modeling of mixture creation process in the cylinder of diesel engine. The simulation was performed using the AVL Fire software. Based on the geometry of the ADCR engine, produced by Andoria-Mot Company, a 3D-CFD model of combustion chamber, channels in the engine head and CNG injector nozzle were created. This model prevented the simulation of the filling, compression and mixture creation process. Specially prepared CNG injector has been placed in the socket of the glow plug, to minimize interference with the structure of the engine. With this solution full functionality of the original fuel supply system was retained with the ability to work with one or two fuels. During studies the location of the gas injector nozzle was changed. The results of simulation are presented for three variants of CNG injector locations.

A single cylinder research engine with negative valve overlap (NVO) and direct gasoline injection was run in a homogeneous charge compression ignition (HCCI) mode. The split fuel injection technique was used, where the first injection was applied during exhaust re-compression, while the second injection was applied at the beginning of main compression. The quantities of the fuel injected at the two timings were varied from the whole fuel injection during NVO to the whole fuel injection during the main compression event. These split fuel ratio sweeps were repeated both for a stoichiometric mixture and for a slightly lean mixture. In the study, NVO reactions were assessed via analysis of the exhaust-fuel mixture composition after the NVO period and referred to the main event combustion. The results showed that fuel injection during NVO resulted in the production of substantial quantities of auto-ignition promoting species, such as acetylene and formaldehyde.

This paper proposes a fast and simple model of a Compressed Natural Gas indirect injection system to predict the system dynamics with high accuracy for different operating conditions. In a retrofit system the CNG Engine Control Unit (ECU) is able to translate the petrol ECU control strategy in CNG operation. The adaptation of the engine to the natural gas type is handled by using the factory engine control strategy embodied in the factory ECU. The ECU monitors the engine through various sensors and controls its operation using a variety of actuators. Because of many input parameters, the control over the engine becomes quite complex. The use of advanced emission control systems makes such process even more complicated. The new Gas Control Unit is used to reprogram the ECU control parameters to correspond with the use of Natural Gas along with the characteristics of the Natural Gas injectors.

This paper focuses on the issues concerning gyroplane powertrain cooling. The Rotax 912S engine was selected as a propulsion system following a detailed analysis. A one-dimensional model, simulated with the AVL Boost software, was applied to determine the heat balance of the engine and the heat flux penetrating through each of engine's surfaces. The geometrical quantities defined in the model were obtained by measuring a three-dimensional geometry provided by an authorized Rotax engine supplier company. Calculation results were then verified by comparing the obtained values with data available from the Rotax 912S engine and with the values of individual parameters given in the literature.

The article presents the simulation results of the combustion process made based on a 3D-CFD mathematical model of the aircraft radial engine. The object of research was the 9-cylinder aircraft engine ASZ-62IR. The model comprised of the internal geometry of the cylinder and pipes in the cylinder head together with the inlet pipe. The model has been verified on the base of the pressure characteristics in the inlet pipe obtained from the experiment. In order to reproduce the same process of mixture formation as in the real engine, the model involved the process of induction, compression and combustion. The conducted research was aimed at verifying the influence of switching off one of the spark plugs on the combustion process. The simulation was done for three versions of ignition, for two spark plugs at the same time, only the front spark plug, only the rear spark plug. The research has been conducted in the conditions of maximum constant power of engine that is 686 kW.

This paper seeks to examine the effect of distance of the gas injector from an inlet valve on the combustion process in a LPG fuelled SI engine under varied injection timing. Tests were conducted at an engine test stand, where the operating conditions of the engine were maintained stable. The tests were undertaken on an indirect injection spark ignition engine under partial load and at a constant speed. Holes in the inlet pipes were drilled in order to test for four variants of injection nozzle distance from the combustion chamber into which 4 mm diameter nozzles were successively mounted. Each given distance was measured along the symmetry axis of the inlet port, which represents a real path of the fuel-air mixture. The results show that the engine performance is affected more by the injector distance from the inlet valve than by varied LPG injection timing. Consequently, cycle-to-cycle variations of main combustion parameters and engine performance parameters were analyzed.

City buses are equipped with an increasing number of electrical devices that are designed to improve the driver work and increase passengers' comfort. The alternator must therefore meet the requirements of increased levels of electric energy demand. In this paper, the focus is set on the amount of chemical energy in the fuel transformed into electric energy by the alternator, especially in the case of urban transport. The article presents the results of operating states of the alternator in the city bus while driving. During the study waveforms of rotational speed and load current of power generation system were recorded. The results of measurements made it possible to draw histograms showing the share of working time in different points of the alternator work. Only about 43% of the total working time corresponds to the bus stop and the operation of the idle speed of the alternator 2250 rpm.

Nowadays, there is a permanent need to develop alternative fuel production and combustion technologies. The general objective indicated in Directive 2009/28/EC for biofuels in Poland is application in transport 10% of renewable energy by 2020 and 20% by 2030. In Poland, it can be achieved by adding bio-components to liquid fuels. Flexible fuel vehicles are not as popular in Europe as in Brazil, so further ethanol processing is justified. The researched synthetic gasoline was obtained from bioethanol at the Ekobenz Company Ltd. in Poland. In 2008, Sasol launched its 100% synthetic jet fuel produced by CTL (Coal to Liquids). A variety of engine concepts was tested and evaluated in terms of the key criteria for use as a range extender developed by AVL Company. The Wankel engine has been selected for the vehicle prototype as the most compact and of excellent NVH behaviour. The use of this engine in light helicopters is also considered.