THE ABILITY OF THE MAIN ROAD TRAIN TO OVERCOME STEEP ROAD CLIMBS

The analysis of changes in the dynamic characteristics of the transport operation of a trunk road train in road conditions with overcoming sections of obstructed traffic characterized by the presence of steep ascents is considered. The solution of the problem under consideration is presented in the variants of determining the maximum angle of elevation of the road that can be overcome by a road train with the specified operational characteristics and the cost of engine power spent on overcoming these road sections.

Influence of Implementation of Composite Materials in Maritime Industry on CO2 Emission’s Reduction

The future of the composites market looks attractive with opportunities in the transportation, construction, wind energy, pipe - tank, marine, consumer goods, electrical and electronics, aerospace, and others. The composite materials market is expected to reach an estimated $40.2 billion by 2024 and it is forecast to grow at a CAGR of 3.3% from 2019 to 2024. The composite materials that have started to be used in the production of tourist boats, especially those of the yacht type, have proved in practice the designers' expectations for the great advantages they have brought compared to steel. The performance of the new generation ships of this millennium, will require the ever-increasing use of new and innovative materials, to meet the also growing demands of potential buyers of these vehicles. On the other hand, based on the already sanctioned principles of the European Community for the observance of the norms set for CO2 emissions from maritime transport - (Green shipping) in respect of the Kyoto Protocol on Climate Change, it becomes more necessary to produce marine vehicles that significantly reduce the weight of marine vessels, consequently engine power and fuel consumption by significantly reducing CO2 emissions. This study aims to bring a specific analysis of the impact of composite materials to the CO2 emission’s reduction.

High temperature fuel cells to reduce CO2 emission in the maritime sector

Recently the interest in the sustainability of the maritime sector has increased exponentially. The International Maritime Organization (IMO) set as objective the reduction of CO2 emissions by 2030 by a margin of 40% compared to 2008. Recent studies showed that, according to the ships and the emission mitigation method applied, only 15–25% of CO2 reduction is de facto needed. Fuel cells represent an answer to meet this regulation. We propose two different solutions: (i) produce with SOFCs instead of engines the minimum power necessary to cut 20% of the emissions, or (ii) reduce the engine power of about 10% balancing the power requirement using MCFCs with CO2 capture. Using Aspen Plus each solution was investigated. The analysis contemplated LNG steam reforming to produce the H2 necessary for cell operation and the separation and liquefaction of CO2. Two case studies were considered comparing existing passenger ships with engines working on HFO and on LNG respectively. Although both solutions showed potential for the reduction of CO2 emissions respecting the IMO regulations, the SOFC solution requires a major change in the design of the ship, while MCFCs are proposed as an urgent solution allowing ship retrofitting without demanding update.

A Study the Effect of Biodiesel Blends and the Injection Timing on Performance and Emissions of Common Rail Diesel Engines

This paper presents a study on the effect of the ratio of biodiesel and injection timing on the performance of diesel engines and their emissions. The research engine is a cylinder engine AVL-5402, simulated by software AVL-Boost. The simulated fuel includes fossil diesel and biodiesel blended with a replacement rate from 0% to 50%, with a simulation mode of 2200 (rev/min), at a rate of a 25%, 50% and 75% load. In this speed range, the engine has the lowest fuel consumption. The parameters to be evaluated are power, fuel consumption and emissions, based on the proportions of blended biodiesel. The results show that there is a relationship between the proportion of blended biodiesel, injection timing and the parameters of the engine. Specifically, the ratio of the biodiesel blend increases, injection timing tends to move closer to the top dead center (TDC), the tendency reduce engine power, fuel consumption increases, the emissions of CO and soot reduces, while NOx increases.

INCREASING THE COMFORTABILITY OF THE VEHICLE DURING ACCELERATION BY IMPROVING THE DESIGN AND CONTROL METHODS OF THE MOTOR-TRANSMISSION UNIT

The derivative of acceleration with respect to time is used to evaluate and ensure driving comfort during acceleration and deceleration. Frequent and rapid changes in acceleration means frequent and rapid deformation, which can lead to the destruction of the load. The article proposes to minimize the amount of acceleration due to the rational choice of transmission ratios in intermediate gears and the law of changing the engine torque. The use of continuously variable transmissions allows you to solve the problem by choosing a rational law for changing the gear ratio of the transmission. The method of selection at the stage of car design of the maximum effective engine power and transmission ratio in top gear is proposed, taking into account the improved formula for calculating the aerodynamic resistance to motion. The required laws of change in the efficiency of the torque and engine power have been determined. The use of a continuously variable transmission allows the engine to operate at a constant high-speed mode and provides control over the acceleration of the car by changing the fuel supply. It is determined that the engine power expended on the movement with the adjustment of the acceleration of the car will be less than with unregulated acceleration if the exponent at the speed of the car, obtained experimentally, is less than one. Keywords: car; comfort; continuously variable transmission; motor-transmission unit; power; overclocking; aerodynamic resistance; gear ratio

Analysis of technical development of small-sized loaders with on-board swing system

Due to the spread of small-sized loaders with on-board swing system (SLOS), it has become necessary to determine the level of their technical development. To understand the set task, a review of small-sized loaders, their classifications, performance parameters and implements was made. Modern SLOS manufacturers were analysed; their design features; main operating parameters: engine power, load capacity, speed and vehicle weight. An analysis of recent papers describing SLOS performance was conducted. It should be noted that most of them consider specific workflow processes, design features that do not reflect the full range of such machines. To solve this problem, a statistical analysis of theSLOS nomenclature data was performed depending on the classification features and performance indicators. This article presents the assessment of the impact of SLOS performance parameters and classification features on their level of technical development. Based on statistical data, the regression equations of the dependences were obtained: engine power on load capacity; loader weight on load capacity; dependences of performane parameters were plotted. General trends in the technical development of small-sized loaders were established. The vast majority of manufacturers focus on the production of medium-capacity loaders, as they are in the greatest demand. The analysis of the graphs suggests that in the future production of small-sized loaders with the load capacity of up to 1.5 tons, engine power of 60-70 kW and weight of up to 5 tons will increase. We can also predict growing production of compact SLOS with the load capacity of up to 0.5 tons, engine power of 20-30 kW and weighing up to 2 tons, which are widely used in urban landscaping. With the help of the present paper we can predict development trends, establish weaknesses of modern SLOSs and avoid competition when designing new loaders.

THE CHANCES FOR REDUCTION OF VIBRATIONS IN MECHANICAL SYSTEM WITH LOW-EMISSION SHIPS COMBUSTION ENGINES

Development of diesel engines is focused on reduction of exhaust gas emissions, increase of efficiency of the fuel mixture combustion and decrease of fuel consumption. Such engines are referred to as low-emission engines. Low- engines trends bring higher engine power outputs, torques and also increase of vibrations and noisiness level. In order to reduce these vibrations of diesel engines, it is necessary to apply different dynamical elements, which are able to increase an adverse impact of exciting amplitudes. One of the results is application of a pneumatic dual-mass flywheel. The pneumatic dual-mass flywheel is a dynamical element that consists of two masses (the primary and the secondary mass), which are jointed together by means of a flexible interconnection. This kind of the flywheel solution enables to change resonance areas of the mechanical system which consequently leads to reduction of vibrations.

Cavitation treatment of water-fuel mixture for internal combustion engines

The efficiency of cavitation treatment of water-gasoline fuel mixture for power supply of automobile internal combustion engines has been experimentally investigated. It is established that cavitation treatment of this fuel mixture allows to increase the water content in it up to 15–17%, reducing the engine power by only 6–7%. This allows up to 10–15% to increase the cost of gasoline when running engines in city traffic jams and on flat and sloping sections of highways. The description of the automobile electromagnetic vibrating cavitator developed for cavitation processing of water-gasoline fuel which not only provides fuel, economy, but also increases degree of completeness of combustion of water-gasoline fuel mix is resulted. As a result, the ecology of the environment is improving.

Evaluation of energy consumption in the acceleration process of a passenger car

The analysis of the vehicle acceleration process is a current topic based on the aspects related to the general characteristics of the car, its parameters, design, drive unit performance, and the influence of external factors. Therfore in the article, the authors assessed the dynamic and energy parameters of the car motion, in which the intensity of acceleration of the car with different intensities was examined. Acceleration was carried out in two variants, the first for a normal internal combustion engine and the second for the same engine but additionally equipped with a short-term boost system. In this way, it influences the increase in power and energy in the car drive system, changing its acceleration intensity. Variable car acceleration intensity was obtained in the range from 0.12 to 1.37 m/s2 , and energy consumption at the level of 0.4 to 1.2 MJ in the distance of 1/4 mile. The article proposes a combination of energy parameters and engine power in order to assess the acceleration dynamics, for this purpose, the specific energy consumption of the car was determined, ranging from 0.35 to 2.0 J/(kg∙m), which was related to the engine power, denoting it with the dynamics index. The study focuses on the assessment of the relationship between the specific energy consumption and acceleration of passenger cars in the available powertrain system using a new dynamics index. The proposed dynamics index combines the energy and dynamic parameters of the car to be able to objectively quantify the acceleration process.