scholarly journals The assessment of the influence of temperature differences in individual ducts of an intake manifold on the unevenness of air filling in a cylinder of a combustion engine

2008 ◽  
Vol 133 (2) ◽  
pp. 44-53
Author(s):  
Dariusz SZPICA
Keyword(s):  
Thermal State ◽  
Combustion Engine ◽  
Simulation Models ◽  
Test Stand ◽  
Intake Manifold ◽  
Filling Process ◽  
Temperature Deviation ◽  
Influence Of Temperature ◽  
Combus Tion

The paper presents the issues related to the unevenness of air filling inside a cylinder of a combus-tion engine. In order to evaluate such an unevenness a test stand and simulation models have been built. The tests stand allows a full assessment of the influence of selected parameters on the uneven-ness of the filling process. In this case the deviations in individual ducts of an intake manifold have been analyzed. This variant has been repeated in simulation tests, where concentrated models have been used for the description of the phenomena. The tests have shown an approximately 6% influence of a 64oC temperature deviation on the unevenness of the cylinder filling. The simulation tests have not shown a significant impact of the thermal state on the filling process

scholarly journals A research stand for the testing of the sealing properties of the piston-rings-cylinder assembly in a combustion engine

2013 ◽  
Vol 153 (2) ◽  
pp. 54-62
Author(s):  
Grzegorz KOSZAŁKA ◽  
Jacek HUNICZ ◽  
Paweł KORDOS
Keyword(s):  
Control System ◽  
Thermal State ◽  
Combustion Engine ◽  
Test Stand ◽  
Piston Rings ◽  
Measuring Device ◽  
System A ◽  
Research Assumptions

The paper discusses research assumptions and describes a test stand for the investigations of the sealing properties of the piston rings. The research stand includes an engine brake together with a control system, a research engine and a lubrication and engine thermal state stabilization systems. The engine was fitted with a research piston containing a measuring device enabling the recording of fast varying quantities such as the pressures in the space between the rings, axial displacements of the oil sealing rings in the piston grooves and the temperatures of the gas blown through the seal.

scholarly journals THE COMBUSTION ENGINE INTAKE MANIFOLD CFD MODELING DEPENDING ON THE AIRBOX CONFIGURATION

2021 ◽  
Vol 2021 (6) ◽  
pp. 5421-5425
Author(s):  
MICHAL RICHTAR ◽  
◽  
PETRA MUCKOVA ◽  
JAN FAMFULIK ◽  
JAKUB SMIRAUS ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Stationary Flow ◽  
Cfd Modeling ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Computational Fluid Dynamics Cfd

The aim of the article is to present the possibilities of application of computational fluid dynamics (CFD) to modelling of air flow in combustion engine intake manifold depending on airbox configuration. The non-stationary flow occurs in internal combustion engines. This is a specific type of flow characterized by the fact that the variables depend not only on the position but also on the time. The intake manifold dimension and geometry strongly effects intake air amount. The basic target goal is to investigate how the intake trumpet position in the airbox impacts the filling of the combustion chamber. Furthermore, the effect of different distances between the trumpet neck and the airbox wall in this paper will be compared.

scholarly journals Numerical Analysis of Diesel Engine with Modified Inlet Valve

2019 ◽  
Vol 8 (6) ◽  
pp. 2378-2380
Keyword(s):  
Numerical Analysis ◽  
Combustion Engine ◽  
Air Flow ◽  
Valve Lift ◽  
Intake Manifold ◽  
Compression Ignition Engine ◽  
Inlet Valve ◽  
Complete Combustion ◽  
Single Cylinder ◽  
Flow Motion

The Internal combustion engine is one of the widely used mechanical system. The primary aspect of all types of engines is the amount of power produced which, is affected by the complete combustion of a mixture of air and fuel. The objective of this present work is to outline the improved performance of single-cylinder Compression Ignition engine with the aid of geometrical modifications of Inlet manifold. The Study is performed on Kirlosakr CI engine. For modeling of engine assembly, CATIA V5 Software has been used. The Numerical simulations are performed with Ansys 14.5 and solver used as CFX. In this work, two different engine models such as Conventional valve and Modified valve with plate is being considered for CFD analysis. The simulation study of air flow motion with a valve lift of 4 mm, 6 mm and 8 mm is performed for both valve configurations. This numerical analysis aims to maximize the air velocity in the inlet valve with minimum turbulence which in turn improves the engine performance. The study is performed on the single cylinder four-stroke variable compression ratio diesel engines. In the present study, the air flow motion inside the intake manifold of an engine is simulated and investigations are performed by considering the six conditions of the intake valve. The results obtained acts as a basis for further investigation of a variety of valve geometry.

Unsteady Responses of the Impeller of a Centrifugal Compressor Exposed to Pulsating Backpressure

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Mengying Shu ◽  
Mingyang Yang ◽  
Ricardo F. Martinez-Botas ◽  
Kangyao Deng ◽  
Lei Shi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Combustion Engine ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Intake Manifold ◽  
Unsteady Simulation

The flow in intake manifold of a heavily downsized internal combustion engine has increased levels of unsteadiness due to the reduction of cylinder number and manifold arrangement. The turbocharger compressor is thus exposed to significant pulsating backpressure. This paper studies the response of a centrifugal compressor to this unsteadiness using an experimentally validated numerical method. A computational fluid dynamic (CFD) model with the volute and impeller is established and validated by experimental measurements. Following this, an unsteady three-dimensional (3D) simulation is conducted on a single passage imposed by the pulsating backpressure conditions, which are obtained by one-dimensional (1D) unsteady simulation. The performance of the rotor passage deviates from the steady performance and a hysteresis loop, which encapsulates the steady condition, is formed. Moreover, the unsteadiness of the impeller performance is enhanced as the mass flow rate reduces. The pulsating performance and flow structures near stall are more favorable than those seen at constant backpressure. The flow behavior at points with the same instantaneous mass flow rate is substantially different at different time locations on the pulse. The flow in the impeller is determined by not only the instantaneous boundary condition but also by the evolution history of flow field. This study provides insights in the influence of pulsating backpressure on compressor performance in actual engine situations, from which better turbo-engine matching might be benefited.

scholarly journals A Design of the Compression Chamber and Optimization of the Sealing of a Novel Rotary Internal Combustion Engine Using CFD

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2362
Author(s):  
Savvas Savvakis ◽  
Dimitrios Mertzis ◽  
Elias Nassiopoulos ◽  
Zissis Samaras
Keyword(s):  
Internal Combustion Engine ◽  
Cfd Simulation ◽  
Combustion Engine ◽  
Numerical Study ◽  
Simulation Models ◽  
Internal Combustion ◽  
Intake Port ◽  
Significant Difference ◽  
Port Design ◽  
Compression Chamber

The current paper investigates two particular features of a novel rotary split engine. This internal combustion engine incorporates a number of positive advantages in comparison to conventional reciprocating piston engines. As a split engine, it is characterized by a significant difference between the expansion and compression ratios, the former being higher. The processes are decoupled and take place simultaneously, in different chambers and on the different sides of the rotating pistons. Initially, a brief description of the engine’s structure and operating principle is provided. Next, the configuration of the compression chamber and the sealing system are examined. The numerical study is conducted using CFD simulation models, with the relevant assumptions and boundary conditions. Two parameters of the compression chamber were studied, the intake port design (initial and optimized) and the sealing system size (short and long). The best option was found to be the combination of the optimized intake port design with the short seal, in order to keep the compression chamber as close as possible to the engine shaft. A more detailed study of the sealing system included different labyrinth geometries. It was found that the stepped labyrinth achieves the highest sealing efficiency.

Probabilistic Analyses for the Performance Characteristics of the Main Bearings in an Operating Engine Due to Variability in Bearing Properties

2003 ◽  
Author(s):  
Jin Wang ◽  
Nickolas Vlahopoulos ◽  
Zissimos P. Mourelatos ◽  
Omidreza Ebrat ◽  
Kumar Vaidyanathan
Keyword(s):  
Design Space ◽  
Combustion Engine ◽  
Hydrodynamic Lubrication ◽  
Simulation Models ◽  
Threshold Value ◽  
Integrated System ◽  
Probabilistic Methods ◽  
System Level ◽  
Oil Viscosity ◽  
Main Bearing

This paper presents the development of surrogate models (metamodels) for evaluating the bearing performance in an internal combustion engine. The metamodels are employed for performing probabilistic analyses for the engine bearings. The metamodels are developed based on results from a simulation solver computed at a limited number of sample points, which sample the design space. An integrated system-level engine simulation model, consisting of a flexible crankshaft dynamics model and a flexible engine block model connected by a detailed hydrodynamic lubrication model, is employed in this paper for generating information necessary to construct the metamodels. An optimal symmetric Latin hypercube algorithm is utilized for identifying the sampling points based on the number and the range of the variables that are considered to vary in the design space. The development of the metamodels is validated by comparing results from the metamodels with results from the actual simulation models over a large number of evaluation points. Once the metamodels are established they are employed for performing probabilistic analyses. The initial clearance between the crankshaft and the bearing at each main bearing and the oil viscosity comprise the random variables in the probabilistic analyses. The maximum oil pressure and the percentage of time (the time ratio) within each cycle that a bearing operates with oil film thickness less than a user defined threshold value at each main bearing constitute the performance variables of the system. The availability of the metamodels allows comparing the performance of several probabilistic methods in terms of accuracy and computational efficiency. A useful insight is gained by the probabilistic analysis on how variability in the bearing characteristics affects its performance.

Probabilistic Main Bearing Performance for an Internal Combustion Engine

2004 ◽  
Author(s):  
Zissimos P. Mourelatos ◽  
Nickolas Vlahopoulos ◽  
Omidreza Ebrat ◽  
Jinghong Liang ◽  
Jin Wang
Keyword(s):  
Performance Measures ◽  
Probabilistic Analysis ◽  
Combustion Engine ◽  
Random Variables ◽  
Simulation Models ◽  
Threshold Value ◽  
Oil Viscosity ◽  
Main Bearing ◽  
Structural Dynamic ◽  
Engine System

A probabilistic analysis is presented for studying the variation effects on the main bearing performance of an I.C. engine system, under structural dynamic conditions. For computational efficiency, the probabilistic analysis is based on surrogate models (metamodels), which are developed using the kriging method. An Optimum Symmetric Latin Hypercube (OSLH) algorithm is used for efficient “space-filling” sampling of the design space. The metamodels provide an efficient and accurate substitute to the actual engine bearing simulation models. The bearing performance is based on a comprehensive engine system dynamic analysis which couples the flexible crankshaft and block dynamics with a detailed main bearing elastohydrodynamic analysis. The clearance of all main bearings and the oil viscosity comprise the random variables in the probabilistic analysis. The maximum oil pressure and the percentage of time within each cycle that a bearing operates with oil film thickness below a threshold value of 0.27 μm at each main bearing constitute the system performance measures. Probabilistic analyses are first performed to calculate the mean, standard deviation and probability density function of the bearing performance measures. Subsequently, a probabilistic sensitivity analysis is described for identifying the important random variables. Finally, a Reliability-Based Design Optimization (RBDO) study is conducted for optimizing the main bearing performance under uncertainty. Results from a V6 engine are presented.

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