scholarly journals Increased Internal Combustion Engine Efficiency with Optimized Valve Timings in Extended Stroke Operation

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2750
Author(s):  
Andyn Omanovic ◽  
Norbert Zsiga ◽  
Patrik Soltic ◽  
Christopher Onder
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Measurement Data ◽  
Optimization Procedure ◽  
Internal Combustion ◽  
Valve Train ◽  
Effective Measure ◽  
Lower Torque ◽  
Variable Valve

Spark-ignited internal combustion engines are known to exhibit a decreased brake efficiency in part-load operation. Similarly to cylinder deactivation, the x-stroke operation presented in this paper is an adjustable form of skip-cycle operation. It is an effective measure to increase the efficiency of an internal combustion engine, which has to be equipped with a variable valve train to enable this feature. This paper presents an optimization procedure for the exhaust valve timings applicable to any valid stroke operation number greater than four. In the first part, the gas spring operation, during which all gas exchange valves are closed, is explained, as well as how it affects the indicated efficiency and the blow-by mass flow. In the second part, a simulation model with variable valve timings, parameterized with measurement data obtained on the engine test, is used to find the optimal valve timings. We show that in 12-stroke operation and with a cylinder load of 5 Nm, an indicated efficiency of 34.3% is achieved. Preloading the gas spring with residual gas prevents oil suction and thus helps to reduce hydrocarbon emissions. Measurements of load variations in 4-, 8-, and 12-stroke operations show that by applying an x-stroke operation, the indicated efficiency remains high and the center of combustion remains optimal in the range of significantly lower torque outputs.

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 Studies on the dynamics the valve train with machined valve springs

2017 ◽  
Vol 168 (1) ◽  
pp. 100-109
Author(s):  
Krystian SICZEK ◽  
Krzysztof SICZEK
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Numerical Models ◽  
Internal Combustion ◽  
Valve Train ◽  
Combustion Engines ◽  
Dynamic Parameters ◽  
The Finite Element Method ◽  
Mathematical Relationships

An analysis of the literature for currently used solutions of valve trains in internal combustion engines and analytical studies on the dynamics the valve train of the internal combustion engine provided with machined valve springs were carried out. The aim of the study was to compare the dynamic parameters of the two valve trains for the established internal combustion engine: the first one equipped with machined springs and the second one with coil springs. The numerical models for investigated valve trains, using the Finite Element Method and additional mathematical relationships were developed and presented in the article. The article describes the results of the researches and formulated conclusions.

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.

Effect of Engine Operating Parameters on Combustion and Emission Characteristics

1992 ◽  
Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Internal Combustion ◽  
Operating Parameters ◽  
Emission Characteristics ◽  
Pollutants Emission

Abstract Numerical simulation of flow, combustion, heat release rate and pollutants emission characteristics have been obtained using a single cylinder internal combustion engine operating with propane as the fuel. The data are compared with experimental results and show excellent agreement for peak pressure and the rate of pressure rise as a function of crank angle. The results obtained for NO and CO are also found to be in good agreement and are similar to those reported in the literature for the chosen combustion chamber geometry. The results have shown that both the combustion chamber geometry and engine operating parameters affects the flame growth within the combustion chamber which subsequently affects the pollutants emission levels. The code employed the time marching procedure and solves the governing partial differential equations of multi-component chemically reacting fluid flow by finite difference method. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.

scholarly journals Individual drive of internal combustion engine lubrication system based on switched reluctance motor

2020 ◽  
Vol 6 (2) ◽  
pp. 146-151
Author(s):  
Ihor Holovach ◽  
◽  
Lidiia Kasha ◽  
Ivan Hudzii
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Switched Reluctance Motor ◽  
Internal Combustion ◽  
Hydrodynamic Resistance ◽  
Lubrication System ◽  
Resistance Characteristic ◽  
Switched Reluctance ◽  
Reluctance Motor

The article analyses the modern lubrication systems for internal combustion engines. Systems with mechanical drive components that contain mechanical and electronic components have been found to have a number of disadvantages. In particular, when the internal combustion engine is started cold, when the viscosity of the oil is high, the hydrodynamic resistance characteristic rises sharply, which leads to high pressure at low speeds and the drive requires low pump speeds. Again, the increase in oil temperature causes a decrease in viscosity, the hydrodynamic resistance characteristic becomes flatter. This, in turn, reduces the pressure in the lubrication system and requires an increase in pump speed in order to keep the pressure constant. Based on the analysis, the requirements for lubrication systems are formulated and a separate lubrication system with forced oil supply is proposed in this paper. For the drive of pump lubrication system of the internal combustion engine, a switched reluctance motor is proposed and calculated. Such motor by its qualities is one of the most useful in this type of systems.

scholarly journals Assessment of thermodynamic cycle of internal combustion engine in terms of rightsizing

2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Combustion Process ◽  
Thermodynamic Cycle ◽  
Internal Combustion ◽  
Research Problem ◽  
Combustion Engines ◽  
Operating Characteristics ◽  
Swept Volume

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.

FEATURES OF MEASURING THE CAMSHAFT OF INTERNAL COMBUSTION ENGINES

2021 ◽  
Vol 4 (30) ◽  
pp. 99-105
Author(s):  
A. V. Summanen ◽  
◽  
S. V. Ugolkov ◽  
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Technical Condition ◽  
Combustion Engines

This article discusses the issues of assessing the technical condition of the camshaft, internal combustion engine. The necessary parameters for assessing the technical condition of the engine camshaft have been determined. How and how to measure and calculate this or that parameter is presented in detail. Methods for calculating the parameters are presented. A scheme and method for measuring neck wear, determining the height of the cam, determining the beating of the central journal of the camshaft are proposed. The main defects of the camshafts are presented. The issues of the influence of these parameters on the operability of the camshaft and the internal combustion engine as a whole are considered.

Possibility of using gas lubricant in the cylinders of internal combustion engines of transport vehicles

2021 ◽  
pp. 13-20
Author(s):  
Keyword(s):  
Internal Combustion Engine ◽  
Bearing Capacity ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Engine Piston ◽  
Suspension Stiffness ◽  
Gas Layer

The prospects of using the gas-static suspension of the internal combustion engine piston in transport vehicles and power plants are considered. The diagram of the piston and the method for calculating the stiffness and bearing capacity of the gas layer surrounding the piston are presented, as well as the results of experiments that showed the relevance of this method. The possibility of gas and static centering of the engine piston is confirmed. Keywords: internal combustion engine, piston, gasstatic suspension, stiffness, bearing capacity, gas medium. [email protected]

Application of precision chronometric technologies for monitoring deviations in the internal combustion engine operation

2021 ◽  
Author(s):  
E.T. Plaksina ◽  
A.B. Syritsky ◽  
A.S. Komshin
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
The Arctic ◽  
Diagnostic Systems ◽  
Time Intervals ◽  
Angle Sensor ◽  
Engine Operation ◽  
Working Cycle

The article considers the main methods of internal combustion engine diagnostics. A method based on measuring the time intervals between the phases of the working cycle of the mechanism is described. An algorithm for measuring the time intervals from the formulation of the problem to the proof of the efficiency of this method on an internal combustion engine has been determined. The installation of the angle sensor on the crankshaft of the experimental bench engine VAZ 21126 is shown. The basis for the construction of a mathematical model of the crankshaft is presented and the main factors influencing its movement are identified. A criterion has been established according to which the misfire is determined most accurately. The results obtained can be used for developing diagnostic systems for internal combustion engines, as well as engines operating in extreme conditions, for example, beyond the Arctic Circle, on ships, etc.

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