scholarly journals Improving the energy efficiency of a piston engine based on the use of a numerical method for forming the laws of motion of gas distribution valves

2021 ◽  
Vol 279 ◽  
pp. 01021
Author(s):  
Alexander Vasilyev ◽  
Yulia Bakhracheva ◽  
Evgenij Ageev
Keyword(s):  
Gas Exchange ◽  
Numerical Method ◽  
Internal Combustion Engines ◽  
Maximum Efficiency ◽  
Combustion Engines ◽  
Gas Distribution ◽  
Operating Modes ◽  
Exchange Processes ◽  
Valve Motion

The increase in the power, economic and environmental performance of modern internal combustion engines is largely due to the improvement of the system that controls the gas exchange processes. Its characteristics determine the quality of filling and cleaning of the cylinders in various operating modes, the loss of power for gas exchange and, consequently, the indicator and effective indicators of the engine. The issues of mathematical modeling of gas exchange processes in combination with the study and improvement of the gas distribution mechanism are considered. The results of experimental and computational studies of gas exchange of tractor diesel are presented. Reserves for improving the gas exchange and the engine as a whole are identified based on the choice of optimal valve timing phases and valve motion laws. They provide a reduction in the modulus of the average pressure of the pump passages in the range of operating modes by 12 - 14 %, which contributed to a decrease in the specific effective fuel consumption by 1.4 ÷ 2.2 g/kWh. The above allows us to conclude that the use of a generalized step-by-step numerical method for synthesizing the law of motion of a pusher with an upper stand allows us to obtain the maximum efficiency characteristics of the gas distribution in the presence of a number of restrictions.

A New Single-Zone Multi-Stage Scavenging Model for Real-Time Emissions Control in Two-Stroke Engines

2019 ◽  
Author(s):  
Abdullah U. Bajwa ◽  
Mark Patterson ◽  
Taylor Linker ◽  
Timothy J. Jacobs
Keyword(s):  
Gas Exchange ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Combustion Engines ◽  
Thermodynamic State ◽  
Multi Stage ◽  
Exchange Processes ◽  
Proposed Model ◽  
Perfect Mixing ◽  
And Control

Abstract Gas exchange processes in two-stroke internal combustion engines, i.e. scavenging, remove exhaust gases from the combustion chamber and prepare the fuel-oxidizer mixture that undergoes combustion. A non-negligible fraction of the mixture trapped in the cylinder at the conclusion of scavenging is composed of residual gases from the previous cycle. This can cause significant changes to the combustion characteristics of the mixture by changing its composition and temperature, i.e. its thermodynamic state. Thus, it is vital to have accurate knowledge of the thermodynamic state of the post-scavenging mixture to be able to reliably predict and control engine performance, efficiency and emissions. Several simple-scavenging models can be found in the literature that — based on a variety of idealized interaction modes between incoming and cylinder gases — calculate the state of the trapped mixture. In this study, boundary conditions extracted from a validated 1-D predictive model of a single-cylinder two-stroke engine are used to gauge the performance of four simple scavenging models. It is discovered that the assumption of thermal homogeneity of the incoming and exiting gases is a major source of inaccuracy. A new non-isothermal multi-stage single-zone scavenging model is thus, proposed to address some of the shortcomings of the four models. The proposed model assumes that gas-exchange in cross-scavenged two-stroke engines takes place in three stages; an isentropic blowdown stage, followed by perfect-displacement and perfect-mixing stages. Significant improvements in the trapped mixture state estimates were observed as a result.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

Model-based compressor surge avoidance algorithm for internal combustion engines utilizing cylinder deactivation during motoring conditions

2019 ◽  
pp. 146808741988347
Author(s):  
Alexander H Taylor ◽  
Troy E Odstrcil ◽  
Aswin K Ramesh ◽  
Gregory M Shaver ◽  
Edward Koeberlein ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Engine Exhaust ◽  
Engine Operation ◽  
Aftertreatment System ◽  
Cylinder Deactivation ◽  
Valve Motion ◽  
Compressor Surge ◽  
Intake Manifold Pressure

Cylinder deactivation is an efficient strategy for diesel engine exhaust aftertreatment thermal management. Temperatures in excess of 200 °C are necessary for peak NO x conversion efficiency of the aftertreatment system. However, during non-fired engine operation, known as motoring, conventional diesel engines pump low-temperature air through the aftertreatment system. One strategy to mitigate this is to deactivate valve motion during engine motoring. There is a specific condition where care must be taken to avoid compressor surge during the onset of valve deactivated motoring when following high load operation. This study proposes and validates an algorithm which (1) predicts the intake manifold pressure increase instigated while transitioning into cylinder deactivation during motoring, (2) estimates future mass air flow, and (3) avoids compressor surge by implementing staged cylinder deactivation during the onset of engine motoring operation.

Modeling of Variable Intake Valve Timing in SI Engine

2006 ◽  
Author(s):  
S. Ahmad Ghazi Mir Saied ◽  
S. Ali Jazayeri ◽  
Amir H. Shamekhi
Keyword(s):  
Internal Combustion Engines ◽  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Major Influence ◽  
Combustion Engines ◽  
Intake Valve ◽  
Si Engine ◽  
Operating Condition ◽  
Valve Motion ◽  
Engine Map

In internal combustion engines valve events and timings are among the most important parameters which have a major influence on the engine’s operation and volumetric efficiency. By using camless valvetrain strategy, improvement in fuel economy as well as an increase in entering air charge is found throughout the engine map with the largest benefits arising from low speed operating conditions. The system offers a continuously variable and independent control of virtually all parameters of valve motion. This permits optimization of valve events for each operating condition without any compromise. In this paper we describe a phenomenological model for an unthrottled operation of a camless intake process of spark-ignited (SI) engine. Initially the cylinder breathing dynamics is modeled and results are validated with experimental data of a conventional engine with cam-driven valve profile during unthrottled operation. Then we determine the most optimized intake valve profile in order to have the most volumetric efficiency and proper operation for each operating condition based on the existing model and using numerical techniques.

scholarly journals Quality Management of Aluminum Pistons with the Use of Quality Control Points

2020 ◽  
Vol 28 (1) ◽  
pp. 29-33
Author(s):  
Grzegorz Ostasz ◽  
Karolina Czerwińska ◽  
Andrzej Pacana
Keyword(s):  
Quality Control ◽  
Production Process ◽  
Internal Combustion Engines ◽  
Control Point ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Control Points ◽  
Control Methods ◽  
Aluminium Piston

AbstractThe publication analyses the way of managing and improving the quality of the production process of aluminum pistons for internal combustion engines. The aim of the article is to propose a method of analysis of the effectiveness of individual control methods used in the process of controlling the aluminium piston. Thanks to the location of a control point with the highest share of product non-compliance detection in the production process, it is possible to reduce quality control points by less effective points, which will contribute to lower costs or shorten the time of production processes. In view of the increasing demands on the efficiency of the checkpoints for components in internal combustion engines, the issue is important and topical.

Sign in / Sign up

Export Citation Format

Share Document