Influence of the combustion chamber geometry on the scavenging of a four-stroke internal-combustion engine during the valve overlap period

2016 ◽  
Vol 230 (14) ◽  
pp. 1873-1890
Author(s):  
Nicolas-Ivan Hatat ◽  
David Chalet ◽  
François Lormier ◽  
Pascal Chessé
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
One Dimensional ◽  
Digital Testing ◽  
The One ◽  
Small Engines ◽  
Variable Valve ◽  
Valve Overlap ◽  
The Impact

The performance of an internal-combustion engine is directly related to the fuel quantity that can react with the oxygen in the air during the exothermic oxidation step, also called combustion. Thus, the amount of fuel introduced is intrinsically linked to the air volume that can be admitted into the cylinder (air filling of the cylinder). Hence keeping the air in the cylinder is one of the most important concepts to predict in simulations. Nevertheless, the phenomenon of air filling depends on many parameters. Also, the discharge coefficients, and the impact of the piston presence near the valves on the flow, during valve overlap are investigated. For this, a digital flow bench is constructed to reproduce a series of tests carried out on a flow test bench functioning as a result of the reduction in the pressure. In this paper, the engine studied is a 125 cm3 single-cylinder four-stroke atmospheric type with two valves. Thus, the idea of this paper is to treat the case of engines with large valve overlaps as small engines or engines with variable valve timing. First, traditional tests through a single valve are performed. The forward and reverse directions are systematically tested to ensure proper operation of the digital testing, and to determine the differences between tests and simulations in the case of conventional configurations. Then, the flow through the entire cylinder head, i.e. the intake valve–cylinder with piston–exhaust valve system, is tested and studied. The aim is to compare the results obtained by the tests and the simulations during the valve overlap period. Significant differences were highlighted between the rates measured in one-dimensional simulations and in the tests. It was noteworthy that the one-dimensional code overestimated the mass passing through the system during valve overlap by about one fifth of the estimated mass passing through the system from the results obtained with the test rig.

Study on Non-Axisymmetric 3D Curved Surface Turning by Driven-Type Rotary Tool Synchronized With Spindle

2021 ◽  
Author(s):  
Akane Ishizuka ◽  
Narimasa Ueda ◽  
Yoshitaka Morimoto ◽  
Akio Hayashi ◽  
Yoshiyuki Kaneko ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Curved Surface ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Cam Mechanism ◽  
Rotary Tool ◽  
Variable Valve ◽  
New System

Abstract Since shifting to electric vehicles as a countermeasure against global warming is not always easy to complete, the hybrid car has been considered as another possible solution. However, based on the calculation of total CO2 emissions, all hybrid cars which will constitute 90% of all cars are expected to be equipped with an internal combustion engine even after 2030. Therefore, further efficiency improvement of the internal combustion engine is necessary. One of the key factors is the variable valve timing and variable lift with the 3D cam mechanism. Since conventional technology uses a complicated link mechanism and servo motor control, this leads a problem to set into small cars or motorcycles because they cannot afford to install the variable valve timing and variable lift with cam mechanism. To solve this problem, a cam shape with a three-dimensional curved surface has been proposed. In order to create this shape, the machining method for non-axisymmetric curved surface turning (NACS-Turning) is required. To build the new system, our research group has proposed a new machining method using a driven type rotary tool and a linear motor driven moving table to enable to achieve NACS-Turning. In this new system, a new tool rotation axis (B axis) is adopted to synchronize its rotational position with the rotational position of the spindle (C axis) holding the workpiece, the X1-, X2-, and Z-Axis positions in total. In this paper, the new hardware configuration is proposed to overcome the present machining accuracy.

scholarly journals The impact of ignition system damage on the emission of toxic substances in a spark-ignition internal combustion engine

2019 ◽  
Vol 179 (4) ◽  
pp. 86-92
Author(s):  
Mieczysław DZIUBIŃSKI ◽  
Ewa SIEMIONEK ◽  
Artur DROZD ◽  
Michał ŚCIRKA ◽  
Adam KISZCZAK ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Exhaust Gas ◽  
Toxic Substances ◽  
Ignition System ◽  
The Impact

The article discusses the impact of ignition system damage on the emission of toxic subcategories in a spark-ignition internal combustion engine. The aim of the work was to develop an analytical model of ignition system diagnostics, test performance and comparative analysis of the results of simulations and experiments. The model developed allows to analyse the basic parameters of the ignition system affecting the content of toxic substances in the exhaust. Experimental tests were carried out using the MAHA MGT5 exhaust gas analyser for four different combustion engines fueled with petrol at various operating conditions. During the tests, the content of toxic substances in the exhaust gas of a properly working engine and the engine working with damage to the ignition system were registered. The tests will be used to assess the impact of the damage of the spark-ignition engine on the emission of individual components of toxic fumes.

scholarly journals Optimal Degree of Hybridization for Spark-Ignited Engines with Optional Variable Valve Timings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8151
Author(s):  
Andyn Omanovic ◽  
Norbert Zsiga ◽  
Patrik Soltic ◽  
Christopher Onder
Keyword(s):  
Internal Combustion Engine ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Valve Train ◽  
Effective Measure ◽  
Optimal Degree ◽  
Variable Valve Train ◽  
Variable Valve

The electric hybridization of vehicles with an internal combustion engine is an effective measure to reduce CO2 emissions. However, the identification of the dimension and the sufficient complexity of the powertrain parts such as the engine, electric machine, and battery is not trivial. This paper investigates the influence of the technological advancement of an internal combustion engine and the sizing of all propulsion components on the optimal degree of hybridization and the corresponding fuel consumption reduction. Thus, a turbocharged and a naturally aspirated engine are both modeled with the additional option of either a fixed camshaft or a fully variable valve train. All models are based on data obtained from measurements on engine test benches. We apply dynamic programming to find the globally optimal operating strategy for the driving cycle chosen. Depending on the engine type, a reduction in fuel consumption by up to 32% is achieved with a degree of hybridization of 45%. Depending on the degree of hybridization, a fully variable valve train reduces the fuel consumption additionally by up to 9% and advances the optimal degree of hybridization to 50%. Furthermore, a sufficiently high degree of hybridization renders the gearbox obsolete, which permits simpler vehicle concepts to be derived. A degree of hybridization of 65% is found to be fuel optimal for a vehicle with a fixed transmission ratio. Its fuel economy diverges less than 4% from the optimal fuel economy of a hybrid electric vehicle equipped with a gearbox.

scholarly journals OPTIMIZATION OF WASTE MOTOR OIL IN SHIP DIESEL WITH HIGH BOOST BY WEAR CRITERION

2018 ◽  
pp. 78-86
Author(s):  
Maxim Igorevich Tarasov ◽  
Georgy Alexandrovich Gauk ◽  
Liudmila Anatolievna Semeniuk
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Optimal Level ◽  
Engine Oil ◽  
Resource Saving ◽  
Engine Wear ◽  
The Impact

The results of modeling the impact of oil burning on the condition of the ship forced trunk piston diesel engine when using lubricants with different operating properties. The dependence of wear rate on oil fume, the quality of used lubricants and marine diesel forcing is obtained by modeling wear using the theory of planning experiments. The area of minimal wear has been determined. There has been detected the most efficient waste oil providing favorable conditions for resource-saving operation of the internal combustion engine. It is inferred that reduction of engine oil fume changes the main parameters of its aging. At the same time, the intensity of oil aging in main directions and of engine wear reduce from 0.75 to 2.25 g/(kW∙h), whereas the fume increases. Its further increase is accompanied by an increase in the rate of oil aging and engine wear. The detected "fracture" depending on И( g y) after passing the border g yopt = 2.25-2.5 g/(kW∙h) is stipulated by different ratio of oil exchange in the lubrication system and the ingress of gases into the crankcase. There has been determined the degree of oil burning, at which sludging and lacquer formation of the internal combustion engine is least intense. The smallest carbon deposits on pistons and in the crankcase of the engine can be observed when the diesel engine is operating in the zone of optimal carbonation. Experimentally, the dependence of tribotechnical properties, in particular, wear of insoluble products of oil aging has been detected at different degrees of oil burning. It is revealed that these characteristics also depend on the quality of the used fuels and lubricants and the conditions of formation and turnover of the oil film on the mirror of the cylinder, the thermal effect on it of the engine workflow. The result of simulation is the prediction of resource-saving operation of marine trunk diesel engines by maintaining oil fume at the optimal level.

scholarly journals Effect of Gas Mixture Composition on the Parameters of an Internal Combustion Engine

10.14311/1540 ◽  
2012 ◽  
Vol 52 (3) ◽  
Author(s):  
Andrej Chríbik ◽  
Marián Polóni ◽  
Ján Lach
Keyword(s):  
Internal Combustion Engine ◽  
Alternative Fuels ◽  
Combustion Engine ◽  
Chemical Properties ◽  
Internal Combustion ◽  
Gas Mixture ◽  
Performance And Emission ◽  
Combustion Gases ◽  
Engine Simulation ◽  
The Impact

This paper deals with the use of the internal combustion piston engine, which is a drive unit for micro-cogeneration units. The introduction is a brief statement of the nature of gas mixture compositions that are useful for the purposes of combustion engines, together with the basic physical and chemical properties relevant to the burning of this gas mixture. Specifically, we will discuss low-energy gases (syngases) and mixtures of natural gas with hydrogen. The second section describes the conversion of the Lombardini LGW 702 combustion engine that is necessary for these types of combustion gases. Before the experimental measurements, a simulation in the Lotus Engine simulation program was carried out to make a preliminary assessment of the impact on the performance of an internal combustion engine. The last section of the paper presents the experimental results of partial measurements of the performance and emission parameters of an internal combustion engine powered by alternative fuels.

scholarly journals A one-dimensional modeling study on the effect of advanced insulation coatings on internal combustion engine efficiency

2020 ◽  
pp. 146808742092158
Author(s):  
Alberto Broatch ◽  
Pablo Olmeda ◽  
Xandra Margot ◽  
Josep Gomez-Soriano
Keyword(s):  
Heat Transfer ◽  
Combustion Engine ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Insulation Material ◽  
One Dimensional ◽  
Engine Efficiency ◽  
Dimensional Modeling ◽  
The One ◽  
The Impact

This article presents a study of the impact on engine efficiency of the heat loss reduction due to in-cylinder coating insulation. A numerical methodology based on one-dimensional heat transfer model is developed. Since there is no analytic solution for engines, the one-dimensional model was validated with the results of a simple “equivalent” problem, and then applied to different engine boundary conditions. Later on, the analysis of the effect of different coating properties on the heat transfer using the simplified one-dimensional heat transfer model is performed. After that, the model is coupled with a complete virtual engine that includes both thermodynamic and thermal modeling. Next, the thermal flows across the cylinder parts coated with the insulation material (piston and cylinder head) are predicted and the effect of the coating on engine indicated efficiency is analyzed in detail. The results show the gain limits, in terms of engine efficiency, that may be obtained with advanced coating solutions.

Study of the effect of the EGR heat exchanger on the internal combustion engine cooling system

2021 ◽  
Keyword(s):  
Heat Exchanger ◽  
Internal Combustion Engine ◽  
Cooling System ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Products ◽  
Simulation Software ◽  
One Dimensional ◽  
Engine Cooling ◽  
Recirculation System

The article presents a study and modification of the cooling system of a KAMAZ R6 in-line diesel engine using a heat exchanger of the combustion products recirculation system in the Simcenter AMESim one-dimensional simulation software. In the course of the research, the problems of engine overheating when using a heat exchanger of the combustion products recirculation system were identified, and possible solutions were proposed and investigated to optimize the temperature level of the coolant in the engine cooling system. Keywords one-dimensional modeling, 1D modeling, ICE, internal combustion engine, heat exchange, cooling system, CO, heat exchanger, heat exchanger, TA

Numerical Analysis of an Internal Combustion Engine Using One-Dimensional Computational Models

2015 ◽  
Author(s):  
Fábio de Castro Radicchi ◽  
João Marcos Gomes Vieira ◽  
Leonardo Fonseca ◽  
José Eduardo Mautone Barros ◽  
Ramón Molina Valle
Keyword(s):  
Numerical Analysis ◽  
Internal Combustion Engine ◽  
Computational Models ◽  
Combustion Engine ◽  
Internal Combustion ◽  
One Dimensional
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