Dynamic Analysis and Experimental Evaluation of Variable Valve Lift System for Internal Combustion Engine with Double Overhead Camshaft

2014 ◽  
Vol 6 (1-2) ◽  
Author(s):  
Saeed A. Albatlan ◽  
Eid S. Mohamed
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Analysis ◽  
Experimental Evaluation ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Valve Lift ◽  
Variable Valve Lift ◽  
Variable Valve

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 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 CFD Port Flow Simulation of Air Flow Rate in Spark Ignition Engine

2020 ◽  
Vol 10 (6) ◽  
pp. 87-95
Author(s):  
SMG Akele ◽  
C. Aganama ◽  
E. Emeka ◽  
Y. Abudu-Mimini ◽  
S. Umukoro ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Flow Rate ◽  
Combustion Engine ◽  
Flow Simulation ◽  
Internal Combustion ◽  
Spark Ignition Engine ◽  
Valve Lift ◽  
Cylinder Wall ◽  
Air Stream ◽  
Study Results

In the early stages of development of internal combustion engine (ICE), limitations such as speed, range, and lifespan led to series of researches resulting in the reduction or elimination of these limitations. Combustion in ICE is a rapid and controlled endothermic reaction between air in oxygen and fuel which is accompanied by significant increase in temperature and pressure with the production of heat, flame and carbon particle deposits. This combustion process is a phenomenon that involves turbulence, loss of air-fuel mixture during inflow and outflow into the cylinder. The objection of this study is to perform port flow analysis on ICE to determine flow rate and swirl at different valve lift under stationary engine parts.Methodology employed to analyze and solve the ICE port flow simulation is the use of CFD software that uses the finite volume method of numerical analysis to solve the continuity, Navier-Stokes and energy equations governing the air medium in the internal combustion engine cylinder. The model geometry for the analysis was generated using the Ansys Design Modeller for one cylinder, one suction port and one exhaust port, and two valves. The domain considered is internal combustion engine suction port with 86741 nodes and 263155 elements. Study results revealed that air mass was more concentrated around the valve and inlet port cross-section with swirling motion seen, air stream experienced turbulence as it flowed downwards inside the cylinder, air stream spread was turbulent which will eventually enhance smooth combustion, swirling air stream moves towards the cylinder wall where it experienced tumbling and turbulent which will eventually enhance smooth combustion. From the simulation it was revealed that mass flow rate of inlet air increases with valve lift.

Dynamics of a Cross-Slider Mechanism As Used in an Internal Combustion Engine

1992 ◽  
Author(s):  
Steven M. Nesbit
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Analysis ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Kinematics And Dynamics ◽  
Total Force ◽  
Internal Mechanism ◽  
The Cross

Abstract A four cylinder internal combustion engine was developed which utilizes a cross-slider as its internal mechanism. The mechanism consists of two perpendicular sliders, each connected at midpoint to a floating gear which mates to two grounded gears pinned off center. A complete kinematic and dynamic analysis was performed to study mechanism behavior in an engine application. As a result of the analysis, the kinematics and dynamics of the mechanism were defined, the engine performance was simulated, the components of the engine were properly sized, and a total force and torque balance was achieved. This article will present the development of the kinematic and dynamic expressions that describe the cross-slider mechanism as used in an internal combustion engine.

A comparison of methods of modelling the bearing surfaces in an internal combustion engine

2011 ◽  
Vol 226 (4) ◽  
pp. 913-920 ◽  
Author(s):  
P D McFadden ◽  
S R Turnbull
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Analysis ◽  
Journal Bearing ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Journal Bearings ◽  
Comparison Of Methods ◽  
Piston Motion ◽  
Piston Cylinder

An existing model for the dynamic analysis of the piston motion in an internal combustion engine has been modified to incorporate a simpler representation of the piston–cylinder interaction, and to represent the main and big-end bearings as lubricated rather than dry journal bearings. The results demonstrate that the differences in calculated bearing forces and output torques are negligible, indicating that the simple dry journal bearing model is sufficient, but show that the modelling of the interaction between piston and cylinder is considerably improved.

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.

Dynamic analysis of piston secondary motion in an internal combustion engine under non-lubricated and fully flooded lubricated conditions

2011 ◽  
Vol 225 (11) ◽  
pp. 2575-2585 ◽  
Author(s):  
P D McFadden ◽  
S R Turnbull
Keyword(s):  
Internal Combustion Engine ◽  
Dynamic Analysis ◽  
Dynamic Model ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Gas Pressure ◽  
Single Cylinder Engine ◽  
Secondary Motion ◽  
Steady Rotation ◽  
Engine Cycle

A dynamic model is presented for the internal combustion engine in which the primary motion of the pistons is determined by the gas pressure in the cylinders rather than by an assumed steady rotation of the crank, and the secondary motion of the pistons is determined by the interaction of the pistons with the cylinder walls under non-lubricated and fully flooded lubricated conditions. Results are presented for the simulation of a single-cylinder engine and show clearly the variations in the secondary translation and rotation of the piston throughout the engine cycle for the non-lubricated condition, and the significant damping of such secondary motions in the fully flooded lubricated condition.

Study of the Variable Valve Timing Effects on Combustion Quality and Fuel Consumption of an Internal Combustion Engine

2020 ◽  
Author(s):  
Augusto César Teixeira Malaquias ◽  
Nilton Antonio Diniz Netto ◽  
José Guilherme Coelho Baêta ◽  
Alysson Fernandes Teixeira ◽  
Sérgio Augusto Passos Costa
Keyword(s):  
Internal Combustion Engine ◽  
Fuel Consumption ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Timing Effects ◽  
Variable Valve
Sign in / Sign up

Export Citation Format

Share Document