A Steady-State Air Motion Study in a V-6 Uniflow Scavenged Two-Stroke Diesel Engine

1988 ◽  
Vol 110 (3) ◽  
pp. 503-508
Author(s):  
T. D. Doan ◽  
E. F. Crawford ◽  
S. J. Hinkle
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Airflow Rate ◽  
Maximum Difference ◽  
Motion Study ◽  
Air Motion ◽  
Insight Into

This paper presents new insight into the causes of cylinder-to-cylinder variation in swirl torque and airflow in uniflow scavenged, two-stroke diesel engines. A V-6 model of such an engine was investigated as a flow rig under steady-state conditions. These variations were found to be primarily caused by the effect of the airbox walls on the air motion. The maximum difference in the baseline cylinder-to-cylinder swirl torque and airflow rate was 11 and 3.5 percent, respectively. Two airbox design modifications, resulting from the study, in turn demonstrated increased cylinder airflow rate and reduced cylinder-to-cylinder swirl torque variation on the flow rig.

scholarly journals Dynamics of marine diesels when using motor oils with different structural characteristics

2021 ◽  
Vol 27 (1) ◽  
pp. 108-119
Author(s):  
Сергей Викторович Сагин ◽  
Тимур Александрович Столярик
Keyword(s):  
Molecular Structure ◽  
Boundary Layer ◽  
Steady State ◽  
Diesel Engine ◽  
Diesel Engines ◽  
Structural Characteristics ◽  
Marine Diesel Engine ◽  
Marine Engine ◽  
Lubricating Layer ◽  
Marine Diesel

Annotation – The influence of the structural characteristics of engine lube oil on the dynamics of a marine diesel engine is considered. It is indicated that micron layers of marine engine lube oils separating the contact surfaces of marine diesel engines acquire the properties of liquid crystals and are characterized by an ordered molecular structure. The qualitative indicator of this structure is the degree of ordering of the molecules, and the quantitative indicator is the thickness of the ordered (boundary) lubricating layer. It is proposed to determine the structural characteristics of marine engine lube oils (the degree of ordering of the molecules of the boundary layer and its thickness) using the optical method of absorption dichroism. A diagram of an experimental setup is presented that allows such studies to be carried out. It has been experimentally established that for Shell Rimula X15 and Castrol TPL 123 engine lube oils (used in the oil system of the Caterpillar CatC18 marine diesel engine), the thickness of the ordered (boundary) lubricating layer is 14.3 ... 14.7 microns and 16.4 ... 16.6 microns, respectively. The degree of ordering of molecules in the boundary layer for Shell Rimula X15 engine lube oil is in the range of 0.56 ... 0.58, for Castrol TPL 123 engine lube oil – in the range of 0.63 ... 0.64. The results of studies of the dynamics of the CatC18 marine diesel engine by Caterpillar, carried out in the starting mode, as well as at various increases and decreases in load, are presented. As indicators, which were used to assess the dynamics of the diesel engine, the overshoot of the rotational speed and the time to reach a new steady state mode were taken. Experiments have confirmed that Castrol TPL 123 engine lube oil, which has a higher molecular structure in the boundary layer compared to Shell Rimula X15 lube oil, ensures the transient processes of the Caterpillar CatC18 marine diesel engine with less overspeed and less time to reach a new state work. The proposed technology for determining the structural characteristics of engine lube oils can be used for any type and grade of oil (mineral or synthetic, high and low viscosity, used both in circulating and cylinder lubrication systems). The proposed method for assessing the dynamic characteristics of marine diesel engines (by overshoot of the speed and the time to reach a steady state of operation in the event of a change in load) can be used for any types of internal combustion engines (low-, medium- and high-speed; as well as performing the functions of both main and auxiliary engines).

A Correlation for Air Velocities in Cylindrical Prechambers of Diesel Engines

1981 ◽  
Vol 103 (3) ◽  
pp. 499-504 ◽  
Author(s):  
B. A. Ajakaiye ◽  
J. C. Dent
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Theoretical Analysis ◽  
Diesel Engines ◽  
Air Velocity ◽  
Additional Tool ◽  
Injection Type ◽  
Air Motion ◽  
Theory And Experiment

Theoretical analysis and measurements of air velocities in cylindrical prechambers of the indirect injection type Diesel engine are reported. Comparisons are made between the theoretical analysis and the measurements for two cylindrical prechambers tested in the present study and the results of previous investigators [4–6], A correlation is derived-to link air velocity in the cylindrical prechamber and known engine parameters. The results show that there is poor and inconsistent agreement between theory and experiment in some of the cases considered. Reasons are suggested to explain these inconsistencies. The derived correlation could serve as an additional tool for the engine designer in predicting air motion and hence combustion and heat transfer in the prechamber of indirect injection diesel engine.

scholarly journals Fault Detection of Diesel Engine Air and after-Treatment Systems with High-Dimensional Data: A Novel Fault-Relevant Feature Selection Method

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 259
Author(s):  
Qilan Ran ◽  
Yedong Song ◽  
Wenli Du ◽  
Wei Du ◽  
Xin Peng
Keyword(s):  
Genetic Algorithm ◽  
Diesel Engine ◽  
Fault Detection ◽  
Correlation Analysis ◽  
Canonical Correlation Analysis ◽  
Diesel Engines ◽  
Canonical Correlation ◽  
High Dimensional Data ◽  
High Dimensional ◽  
Relevant Variables

In order to reduce pollutants of the emission from diesel vehicles, complex after-treatment technologies have been proposed, which make the fault detection of diesel engines become increasingly difficult. Thus, this paper proposes a canonical correlation analysis detection method based on fault-relevant variables selected by an elitist genetic algorithm to realize high-dimensional data-driven faults detection of diesel engines. The method proposed establishes a fault detection model by the actual operation data to overcome the limitations of the traditional methods, merely based on benchmark. Moreover, the canonical correlation analysis is used to extract the strong correlation between variables, which constructs the residual vector to realize the fault detection of the diesel engine air and after-treatment system. In particular, the elitist genetic algorithm is used to optimize the fault-relevant variables to reduce detection redundancy, eliminate additional noise interference, and improve the detection rate of the specific fault. The experiments are carried out by implementing the practical state data of a diesel engine, which show the feasibility and efficiency of the proposed approach.

Effect of altitude conditions on combustion and performance of a turbocharged direct-injection diesel engine

2021 ◽  
pp. 095440702110262
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
High Altitude ◽  
Diesel Engines ◽  
Direct Injection ◽  
Pressure Rise ◽  
Ambient Conditions ◽  
Allowable Limit ◽  
Spray Formation ◽  
Direct Injection Diesel Engine ◽  
And Performance

Market globalization necessitates the development of heavy duty diesel engines that can operate at altitudes up to 5000 m without significant performance deterioration. But the current scenario is that existing studies on high altitude effects are still not sufficient or detailed enough to take effective measures. This study applied a single cylinder direct injection diesel engine with simulated boosting pressure to investigate the performance degradation at high altitude, with the aim of adding more knowledge to the literature. Such a research engine was conducted at constant speed and injection strategy but different ambient conditions from sea level to 5000 m in altitude. The results indicated the effects of altitude on engine combustion and performance can be summarized as two aspects. First comes the extended ignition delay at high altitude, which would raise the rate of pressure rise to a point that can exceed the maximum allowable limit and therefore shorten the engine lifespan. The other disadvantage of high-altitude operation is the reduced excess air ratio and gas density inside cylinder. Worsened spray formation and mixture preparation, together with insufficient and late oxidation, would result in reduced engine efficiency, increased emissions, and power loss. The combustion and performance deteriorations were noticeable when the engine was operated above 4000 m in altitude. All these findings support the need for further fundamental investigations of in-cylinder activities of diesel engines working at plateau regions.

Start-up and Steady-State Performance of a New Renewable Alcohol-To-Jet (ATJ) Fuel in Multiple Diesel Engines

2015 ◽  
Author(s):  
Terrence Dickerson ◽  
Andrew McDaniel ◽  
Sherry Williams ◽  
Dianne Luning-Prak ◽  
Len Hamilton ◽  
...  
Keyword(s):  
Steady State ◽  
Diesel Engines ◽  
Start Up ◽  
Steady State Performance

scholarly journals MODIFYING MATHEMATICAL MODELS FOR CALCULATING OPERATIONAL CHARACTERISTICS OF DIESEL ENGINES BURNING RME BIOFUELS / MATEMATINIŲ MODELIŲ PRITAIKYMAS DYZELIŲ, DIRBANČIŲ RME BIODEGALAIS, DARBO PROCESUI IR EKSPLOATACINIAMS RODIKLIAMS SKAIČIUOTI / ДОРАБОТКА МАТЕМАТИЧЕСКИХ МОДЕЛЕЙ РАСЧЕТА ПОКАЗАТЕЛЕЙ РАБОТЫ ДИЗЕЛЯ НА БИОДИЗЕЛИНАХ РРМЭ

Transport ◽  
2011 ◽  
Vol 26 (1) ◽  
pp. 50-60 ◽  
Author(s):  
Sergejus Lebedevas ◽  
Galina Lebedeva ◽  
Kristina Bereišienė
Keyword(s):  
Diesel Engine ◽  
Mathematical Modelling ◽  
Mathematical Models ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Internal Heat ◽  
Computer Programs ◽  
Toxic Substances ◽  
Load Range ◽  
Operational Characteristics

The article considers and solves the problems of adapting the mathematical models, used in calculating operational characteristics of diesel engines burning mineral diesel oil, to engines converted to RME biofuels. The analysis of mathematical models of calculating the main technical and economic characteristics of diesel engines as well as the parameters of the in-cylinder process and the concentration of toxic substances in the exhaust gases is performed. The need for adjusting the calculation algorithms is also demonstrated. The computer programs based on single-zone thermodynamic models are used in the research. The programs of mathematical modelling are modified, i.e. supplemented with the algorithm for calculating energy characteristics of the combustion products (e.g. specific heat capacity, internal heat, the lower calorific value, etc.). Based on the computer programs, modified for examining diesel engines burning biofuels, the computer-aided mathematical modelling experiment is carried out. The results of modelling are compared with the data obtained in testing the diesel engine 1A41. The mathematical modelling performed demonstrates the accuracy acceptable for solving practical problems: the difference between the obtained calculation results and diesel engine testing data for the load range of (1.0÷0.5) Pi nom does not exceed ± 5÷7%. Higher accuracy of modelling the characteristics of diesel engines, operating in the low- and medium-load modes, may be accounted for by the adjustment of the algorithm for calculating the induction period and the on-set phase of fuel injection. Santrauka Publikacijoje pateikti dyzelio darbo proceso ir eksploatacinių rodiklių skaičiavimo matematinių modelių tobulinimo rezultatai, siekiant matematinius modelius pritaikyti dyzeliui dirbant riebiųjų rūgščių metilesterių, taip pat RME, biodegalais. Atlikta skaičiavimo algoritmų analizė ir pagrįsti pagrindiniai jų tobulinimo aspektai. Sukurtas kompiuterinis programinis modelis, skirtas darbinio kūno dyzelio cilindre energiniams parametrams skaičiuoti (specifinei šilumai, vidinei energijai), dyzeliui dirbant plačiąja elementinės cheminės sudėties biodegalų gama. Atliktas 1A41 dyzelio techninių ir ekonominių bei ekologinių rodiklių modeliavimas kompiuteriu, naudojant patobulintus matematinius modelius. Parodytas gautų rezultatų, pakankamų praktiniams uždaviniams spręsti, tikslumas: dyzeliui dirbant artimos nominaliosios apkrovos režimais (1,0÷0,5) Pi nom skirtumas tarp skaičiavimo ir dyzelio motorinių tyrimų rezultatų neviršija ±5÷7%. Dyzeliui dirbant mažos apkrovos režimu, matematinio modeliavimo rezultatų adekvatumo didinimas susijęs su kuro įpurškimo fazės bei savaiminio užsiliepsnojimo indukcijos periodo skaičiavimo algoritmo tobulinimu. Резюме Рассмотрены и решены задачи адаптации математических моделей расчета показателей дизеля при переводе их работы с минерального дизелина на биодизелины метилового эфира рапсового масла (МЭРМ). Выполнен анализ и дано обоснование направлений доработки расчетных алгоритмов ряда однозонных термодинамических математических моделей, используемых в практике исследования эксплуатационных показателей, параметров индикаторного процесса и эмиссии токсичных компонентов в выхлопных газах дизелей. В форме программного модуля составлен алгоритм расчета энергетических параметров рабочего тела в цилиндре (удельной теплоемкости, теплоты сгорания, внутренней энергии) для топлив с широким элементарным химическим составом. С использованием доработанных компьютерных программ выполнен широкий расчетный эксперимент и сопоставлены его результаты с данными моторных стендовых испытаний одноцилиндрового отсека дизеля 1А41. Показана приемлемая для решения практических задач точность математического моделирования: для нагрузочных режимов (1÷0,5) Pmi расхождения расчетных и экспериментальных значений параметров работы дизеля не превышают ±5÷7%. Повышение качества моделирования показателей дизеля на режимах средних и малых нагрузок связано с уточнением алгоритма расчета периода индукции и фазы начала видимого горения топлива в цилиндре.

Characteristics of injection of diesel fuel, rapeseed oil and their mixtures in diesel engines of various types

2021 ◽  
pp. 167-178
Author(s):  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Rapeseed Oil ◽  
High Speed ◽  
Fuel Injection ◽  
Experimental Studies ◽  
Fuel Injector ◽  
High Speed Diesel ◽  
Engine Type

The necessity of adapting diesel engines to work on vegetable oils is justified. The possibility of using rapeseed oil and its mixtures with petroleum diesel fuel as motor fuels is considered. Experimental studies of fuel injection of small high-speed diesel engine type MD-6 (1 Ch 8,0/7,5)when using diesel oil and rapeseed oil and computational studies of auto-tractor diesel engine type D-245.12 (1 ChN 11/12,5), working on blends of petroleum diesel fuel and rapeseed oil. When switching autotractor diesel engine from diesel fuel to rapeseed oil in the full-fuel mode, the mass cycle fuel supply increased by 12 %, and in the small-size high-speed diesel engine – by about 27 %. From the point of view of the flow of the working process of these diesel engines, changes in other parameters of the fuel injection process are less significant. Keywords diesel engine; petroleum diesel fuel; vegetable oil; rapeseed oil; high pressure fuel pump; fuel injector; sprayer

STUDYING OF THE EFFECT OF WATER-FUEL MIXTURE ON OPERATIONAL PARAMETERS OF A DIESEL

2021 ◽  
Vol 2 (143) ◽  
pp. 54-61
Author(s):  
Sergey V. Borisov ◽  
◽  
Aleksandr E. Lomovskikh ◽  
Oleg E. Prilepin ◽  
Timur R. Mamatkazin ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Aqueous Dispersion ◽  
Fuel Mixture ◽  
Research Purpose ◽  
Regression Equations ◽  
Operational Parameters ◽  
Rough Water ◽  
Minimum Number

Improving the parameters of diesel engines is an urgent task. Work has been carried out to significantly reduce the consumption of their fuel with the introduction of water dispersions into the fuel. Currently, water-fuel emulsions with exotic emulsifiers are mainly tested. (Research purpose) The research purpose is in creation of a water-fuel emulsion without an emulsifier with a simple installation and identifying the influence of the composition and quality of this WFE on the performance of the YaMZ-236 diesel engine. (Materials and methods) The article presents a plant for the preparation of a "rough" water- fuel mixture from diesel fuel according to GOST 32511-2013 and distilled water according to GOST 6709. Authors conducted standard bench tests at the KI-5540- GOSNITI stand with a YaMZ-236 diesel engine with an upgraded fuel system and performed the control of the smoke content of the exhaust gases with the gas analyzer "AUTOTEST". The dependence of diesel performance indicators on the composition and dispersion of water-fuel emulsions without an emulsifier was studied experimentally with a minimum number of tests, but with the maximum possible combination of the values of three variable factors. (Results and discussion) The influence of various water-fuel emulsions on the performance of the diesel engine was evaluated according to the plan of a full factor experiment, including 20 tests. The second-order regression equations were obtained by mathematical processing of the test results. The feasibility of using water-fuel emulsions for diesel engines was confirmed. By modeling a water-fuel mixture without emulsifiers, there was created an aqueous dispersion with drops up to two micrometers. In the load tests of the diesel engine with it, there was noticed an improvement in its performance. (Conclusions) The introduction of 17-20 percent water dispersion with drops of up to two micrometers into diesel fuel reduced the specific fuel consumption by 18 percent, the smokiness in the K indicator by 20- 22, and in the N indicator by 30-35 percent.

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