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EN
The results of an experimental study of the effect of the pressure drop of the air filter pf on the operating parameters and exhaust emissions of a modern CI internal combustion engine of a truck equipped with an electronically controlled power system are presented. The tests were carried out for an air filter with a clean filter cartridge Δpf0 = 0.58 kPa and with a cartridge contaminated after a service mileage (about 50 thousand km) ΔpfD = 2.024 kPa. In each test, engine performance, exhaust emissions and relative change in emissions were determined: CO, NOx, HC, CO2, H2O. It was found that an increase in the filter resistance pf causes a decrease in the filling degree by 12%, engine useful power by almost 10%, exhaust gas temperature by a maximum of 30oC and an increase in specific fuel consumption by almost 5%. Air filter resistance has no significant effect on NOx emissions and HC concentration. There is a reduction in H2O emissions by up to 7%, CO by up to 13% and CO2 by up to 4%, and an increase in oxygen emissions by 15%, depending on operating conditions.
EN
Technological development in the aviation business is usually dictated by diverse safety, economic, environmental, and social goals set by governments, regulatory agencies, and the market. Recently, a rapidly increasing interest in making air transportation climate neutral has been observed. The objective of this study is to analyze the historical trends of aircraft engine fuel efficiency, identify parameters affecting engine efficiency and initiate a discussion about future technology development needed to meet the expectations. The commercial turbofan engines test data comparison is provided in this study, followed by a theoretical assessment. The presented test data trends show a clear correlation between specific fuel consumption decrease and engine parameters like bypass ratio and overall pressure ratio increase, which is confirmed by theoretical assessment. Based on performed analysis results, a bypass ratio increase was indicated as the one potential path to reduce aircraft engine fuel consumption. Bypass ratio improvement could be achieved by fan diameter increase and rotation speed reduction in the case of turbofan engine architecture. A larger fan rotor requires a high torque drive and significantly increases engine weight which could be compensated by the lightweight design of the engine components, e.g., by applying composite materials.
EN
The paper has been presented the methods of nitrogen oxides emission reduction to fulfill the Tier 2 and Tier 3 requirements of the Annex VI of MARPOL Convention. It has been shown the development of marine two-stroke diesel engines and the change of nitrogen oxides emission from 1960 to 2000 and later up to 2020 after the implementation of NOx emission reduction methods. Specific fuel consumption before 2000, and as a prediction and given data in the manufacturers manuals for Tier 3 engines up to 2020, and as only a prediction up to 2030 has been analyzed and elaborated. Impact of nitrogen oxides reduction methods on the specific fuel consumption of the marine diesel engine has been evaluated. Additional emission of some gases to the atmosphere due to the implementation of reduction methods has been determined. EGR and SCR systems have got a lot of imperfections: required to install additional reduction systems (investment cost, required volume in the engine room), need maintenance and operation costs, produced wastes during treatment process. The estimated additional cost is about 0.8 USD/MWh of produced energy, taking into account only the cost of excessive used fuel. The whole increased cost may reach the level two-three times more due to cleaning systems investment costs, their operational cost and waste disposal. It has been the one of the reasons of worsening the transport effectiveness and competitiveness.
4
Content available Diesel engine for aircraft propulsion system
EN
Stricter requirements for power in engines and difficulties in fueling gasoline engines at the airport make aircraft engine manufacturers design new engines capable of combusting fuel derived from JET-A1. New materials used in compression-ignition engines enable weight reduction, whereas the technologies of a Common Rail system, supercharging and 2-stroke working cycle enable us to increase the power generated by an engine of a given displacement. The paper discusses the parameters of about 40 types of aircraft compression ignition engines. The parameters of these engines are compared to the spark-ignition Rotax 912 and the turboprop. The paper also shows trends in developing aircraft compression-ignition engines.
EN
In this paper performance resulted from a single cylinder spark-ignition engine fuelled with 20% by volume of methanol, ethanol, and butanol was studied and compared to gasoline. The experiments were conducted at variable speed and maximum torques. The conditions of stoichiometric air–fuel ratio at wide-open throttle were used. The tests were perfumed at higher useful compression ratio of the used Iraqi gasoline. The test results show that the higher compression ratio for the tested gasoline was 7.5:1. So an Iraqi conventional gasoline has engine HUCR=7.5:1 and its OST= 19 ºBTDC, this compression ratio can be considered low. Adding 20% of alcoholic blends by volume to gasoline improved the engine performance. Within the tested speed range, alcoholic blends produced higher brake powers, volumetric efficiency and thermal efficiency. In addition, it resulted in lower exhaust gases temperatures. The brake specific fuel consumption of the tested alcoholic blend was higher than that for gasoline.
EN
The objective of this research project was to determine the percentage impact of dry-medium air filter being used in Fiat Multijet 1.3 JTD engine on its operational properties (engine flexibility and specific fuel consumption). Experiments were performed according to the requirements of research methods specified in the piston combustion engine standard in force. In order to make comparisons, operational parameters of the power unit (torque, effective power and specific fuel consumption) were measured with dry-medium air filter (with a new filter element) being fitted and with air filter being removed. Each point of respective characteristic curves was determined based on four measurements as their mean value. Also boost pressure, which could be of importance for results, was considered in the experiments. However, the degree of EGR valve lift, the operation of which could also appear to be important, was not taken into account. For each measuring point of respective characteristic curves, the ranges of measurement uncertainties were determined. Expanded standard uncertainties were calculated based on the Guide to the Expression of Uncertainty in Measurement. The experiments being carried out allowed concluding that the engine with air filter was less flexible by approx. 20% when compared to that without air filter, whereas its specific fuel consumption was greater by approx. 9%. The degree of air filter pollution affects its flow resistance and, which is related to this, engine torque and its effective power as well as its flexibility decrease but fuel consumption increases
EN
In this paper is presented a calculation procedure based on Lagrange's interpolation formuła which has been used for describing the external characteristics of compression-ignition engine of the 359 type. The characteristic curves of specific fuel consumption and exhaust gas smokiness were chosen as an example, which had been obtained during examinations on engine test bed for a drive unitfuelled with four types of fuel. Measurements were carried out on a standard engine test bed which is part of laboratory facilities of the Department of Automotive Vehicles Operation, Western Pomeranian University of Technology in Szczecin. The study object was an unsupercharged four-stroke engine of domestic production of the 359 type. It is a six-cylinder compression-ignition drive unit with direct fuel injection system. Interpolating polynomials determined analytically for respective characteristics have been presented in the graphical form, while experimental examination results necessary for obtaining them have been additionally tabulated. The presented methodology allows simplification of particular experiment stages by giving possibility to estimate analytically the missing data and with preservation of a minimum number of measuring points. With small corrections, it may be used in similar examinations on other engine test beds. Its application should support the planning of particular experiment stages but does not, in any case, replace it since determination of engine characteristic curves is possible through research only.
EN
In this paper is presented a calculation method based on Lagrange's interpolation formula which has been used for mathematical description of the performance characteristics of a compression-ignition engine of the 359 type of the Polish production. Its application allows simplification of experimental tests through preservation of a minimum number of measuring points and estimation of other data analytically. In order to minimise the interpolation error occurring with polynomials of high degrees and constant node distances, the characteristics were approximated by spline functions with both solutions being shown comparatively in the graphical form. As calculation examples, the curves of specific fuel consumption and infrared radiation absorption coefficient were chosen, which had been obtained during examinations on engine test bench for a drive unit fuelled with four types of fuel. In addition, results of the experiment required for their determination were tabulated. The presented method may be used in further tests of a given engine as well as on other experimental benches, aiding long-lasting and expensive optimisation of operating parameters when using fuels of plant origin. Description of any performance characteristics by means of interval interpolation is convenient from the practical side and does not cause greater calculation problems since polynomials of low degrees are being used in the procedure.
PL
W artykule przedstawiono metodykę obliczeniową bazującą na interpolacji wielomianowej Lagrange'a, którą wykorzystano do matematycznego opisu charakterystyk zewnętrznych silnika o zapłonie samoczynnym produkcji polskiej typu 359. Jej zastosowanie pozwala na uproszczenie badań doświadczalnych poprzez zachowanie minimalnej ilości punktów pomiarowych i oszacowanie pozostałych danych w sposób analityczny. W celu zminimalizowania błędu interpolacji występującego przy wielomianach wysokich stopni i stałych odległościach węzłów, charakterystyki przybliżano funkcjami sklejanymi, przy czym oba rozwiązania pokazano porównawczo w formie graficznej. Jako przykłady obliczeniowe wybrano krzywe jednostkowego zużycia paliwa i współczynnika absorpcji promieniowania podczerwonego, które uzyskano w badaniach na hamowni silnikowej dla jednostki zasilanej czterema rodzajami paliw. Wyniki eksperymentu wymagane do ich wyznaczenia dodatkowo stabelaryzowano. Prezentowana metodyka może być wykorzystana w dalszych badaniach danego silnika, jak również na innych stanowiskach doświadczalnych, wspomagając długotrwałą i kosztowną optymalizację parametrów roboczych przy stosowaniu paliw pochodzenia roślinnego. Opisanie dowolnych charakterystyk zewnętrznych za pomocą interpolacji przedziałowej jest wygodne od strony praktycznej i nie przysparza większych trudności obliczeniowych, gdyż w procedurze wykorzystuje się wielomiany niskich stopni.
PL
W publikacji opisano metodykę wyznaczania optymalnego z punktu widzenia energooszczędnego sterowania prędkością samochodu pola pracy silnika samochodowego na jego charakterystyce ogólnej. Uwzględniono przy tym najnowsze osiągnięcia w tym zakresie. Uwzględniono również wyniki optymalizacji przebiegowego zużycia paliwa na obszarze zabudowanym, wykorzystując w najdłuższej fazie zmiennego cyklu jezdnego, zwanej przebiegową, dwie podstawowe techniki sterowania – hamowania silnikiem i jazdę z rozłączonym napędem.
EN
Methodology of determining optimum aspect of car engine performance regarding energy saving control of car velocity on the basis of its S.F.C. map has been presented in the paper. The latest designs have been taken into account as well. The results of optimizing the course fuel consumption in city traffic have been considered as well. Optimization results of the course fuel consumption in city traffic have been considered and so two basic driving techniques, i.e. engine braking and idle driving have been used in the longest phase of changeable driving cycle (the course phase).
10
Content available remote Metoda generowania charakterystyk ogólnych silników samochodowych
PL
W pracy przedstawiono zalety autorskiego programu selekcji reprezentatywnych charakterystyk ogólnych silników ZI i ZS, budowy na ich podstawie macierzy liczb jednostkowego zużycia paliwa ge i możliwości ich adaptacji dla innych silników napędowych samochodów osobowych. Omówiono takie zalety przyjętej metody w stosunku do metod stosowanych w innych ośrodkach naukowych, jak dokładność odtworzenia macierzy ge i uniwersalizm zastosowania w ramach programu EKO-DRIVE 2005 do nietypowych zespołów napędowych, np. hybrydowego lub z silnikiem ZI GDI.
EN
The advantages of the author’s research project have been presented in the paper. The project concentrated on selecting representative general characteristics of ZI and ZS engines and on the basis of these data it was possible to build up matrix of numbers of ge specific fuel consumption. It also enabled to adapt them for other types of car engines. Precision of reproducing ge matrix and universal application for the purposes of EKODRIVE 2005 for unconventional power units such as for example hybrid power unit or with ZI GDI engine seems to be a big advantage of the applied method while comparing it to the methods used in other research centres.
EN
Measuring method and calculations of the impact of non-stationary work conditions of car engine torque load upon its effective efficiency have been presented in the paper. The obtained results have been compared to the already achieved results. The applied method of calculation balance and the consumed fuel enabled the writer of the paper to calculate the value of the change of unitary fuel consumption at a work point on engine performance map. The carried out examinations focus on measurements at one measuring length and so the rate of torque load at each of the four gear box ratio (2-5) can be controlled by constant final velocity of driving or by shifting or extending the measuring length against the lowest point ( the measuring length is 'U'-shaped). Finding the right solution to this problem will allow elaborating the calculation algorithm of engine effective efficiency for the examined range of engine performance maps for changeable, non-stationary work conditions. The results make it ąuite explicit that non-stationary work conditions from the engine speed and the engine load impair the effective efficiency of the engine at work in particular gears. Non-stationary mode of engine operation is essential for the higher values of gear box ratio whereas for lower values the engine load really matters.
EN
A method is proposed in the paper to calculate effective efficiency of an engine in nonstationary operating conditions. A reference point for this method is the effective efficiency of the engine derived from its performance map. A research methodology has been developed to this end, the basis of which consists of measurements and calculations of the to tal energy efficiency of a car motion in a variable driving cycle. In order to determine the impact of the road grade, measurements were performed along a geodetically described roadsection in two traffic directions: "up " and "down ". The adopted research scheme allows covering the area of the engine performance map being of interest to us with measuring points. The mean value or rotational speed and its change in unit oftime were adopted as the leading parameters which have a dominating influence on, and result in a reduction of the effective efficiency of the engine. To improve the accuracy of calculations, the variable driving cycle consists of driving phases and idle running. The volume of fuel consumed, not accounted for in the driving phases, being the difference between the calculated and consumed fuel, is a measure of reduction of the effective efficiency of the engine, whilst the unit power of additional motion resistance of the vehicle (a*ni) is a leading parameter in the analyses of the calculation results.
PL
Problem wyznaczenia sprawności efektywnej silnika samochodowego w dynamicznych warunkach pracy jest kluczowym w obliczaniu całkowitej energochłonności ruchu pojazdu i optymalizacji zużycia paliwa. Dlatego wśród niewielu metod praktycznego rozwiązania tego zagadnienia najbardziej atrakcyjną wydaje się jej odniesienie do znanej sprawności efektywnej silnika dla statycznych warunków pracy z charakterystyki uniwersalnej. Autor w obliczeniach tego problemu wykorzystał metodę bilansu energochłonności ruchu w zmiennym pod względem dynamiki przyspieszania cyklu jezdnym i porównania wyników obliczeń z rzeczywistym zużyciem paliwa. Założono w obliczeniach prostoliniowy wpływ dynamiki przyspieszania prędkości obrotowej silnika na spadek sprawności efektywnej wyznaczonej dla statycznych warunków pracy.
EN
The problem of determining the car engine efficiency in dynamic operating conditions is of great importance while calculating the total consumption of energy when the car is driven. It also enables to define the optimum energy consumption. Up till now only few methods have been used but the one which seems to be quite effective is based on the actual engine efficiency at static operating conditions from universal characteristics. The method of energy consumption balance in a variable driving cycle (the dynamics of acceleration was changeable) was applied and the calculation results were compared to the actual fuel consumption. It has been assumed that there was rectilinear influence of acceleration dynamics of the engine upon the decrease of actual efficiency determined for the static operating conditions.
EN
The subject of this report is a description of measuring results and mutual comparison of power, economy and ecological parameters of spark-ignition engines. Four engines equipped with a vertical crank-shaft with power from 3 to 5 kW were compared. These engines were mounted as a drive unit on lawn mowers.
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