Engine Valves—Design and Material Evolution

1987 ◽  
Vol 109 (4) ◽  
pp. 355-361 ◽  
Author(s):  
J. M. Larson ◽  
L. F. Jenkins ◽  
S. L. Narasimhan ◽  
J. E. Belmore
Keyword(s):  
Performance Improvement ◽  
Internal Combustion Engines ◽  
Driving Forces ◽  
Engine Performance ◽  
The United States ◽  
Combustion Engines ◽  
The Past ◽  
Current State ◽  
Valve Function ◽  
Engine Valves

This paper reviews the design and material evolution of poppet valves used in reciprocating internal combustion engines in the United States. Driving forces which led to the current state-of-the-art technology, such as needs for improved durability and cost effectiveness, are described. This paper also endeavors to predict how valve materials, design, and construction will change over the next two decades in response to continual engine performance improvement demands in a worldwide competitive environment. As a basis for understanding the past evolution and future trends in valve design, the key operating parameters that affect valve function are detailed.

scholarly journals Pressure's On

2007 ◽  
Vol 129 (10) ◽  
pp. 44-48
Author(s):  
Frank Wicks
Keyword(s):  
Mechanical Engineering ◽  
Internal Combustion Engines ◽  
Hudson River ◽  
The United States ◽  
Modern World ◽  
Combustion Engines ◽  
The Past ◽  
The World ◽  
American Society ◽  
Great Invention

This article discusses the steamboat has been described as America’s first great invention. The river steamboat helped shape the United States and the world we live in. Steamboats and engines came to define many disciplines of mechanical engineering, and ultimately led to mechanical engineering education and the formation of the American Society of Mechanical Engineers. After two centuries of service, the steam engine created its own obsolescence as it provided the springboard technologies for internal combustion engines, turbo machinery, and electric power. Fulton’s steamboat was a dramatic success. Scheduled passenger and transport immediately followed the first voyage. It was named the Clermont, for the huge Hudson River estate of Robert Fulton’s partner, Robert Livingston, who had funded the project. Robert Fulton’s steamboat and steam engines became things of the past, but we feel their influence all around us. They were the machines that helped create many industries, and were forebears of the marvelous engines and machines of our modern world.

Russia and Europe: historical lessons

2021 ◽  
Author(s):  
Vladimir I. Vinokurov
Keyword(s):  
United States ◽  
Driving Forces ◽  
The United States ◽  
European Countries ◽  
Bilateral Relations ◽  
Current State ◽  
History Of ◽  
The Will ◽  
Otto Von Bismarck ◽  
The Military

Тhe article deals with the results of the Patriotic War of 1812 and the Great Patriotic War of 1941–1945. The analysis of these largest wars in the history of Russian-European relations is carried out, their comparison is made, their nature, character and driving forces are revealed. On the basis of this, it is concluded that both sides have not made the proper conclusions: Europe — in terms of the expediency and consequences of an attack on Russia, thereby violating the will of the iron Chancellor Otto von Bismarck: "Make alliances with anyone, start any wars, but never touch the Russians." Russia — timely opening and preparation for the upcoming tests in relations with Europe. Against the background of more than 200 years of history, the current state of relations between Russia and Europe, which has reached a low level, is considered. Although the leading European states, Germany and France, have not stopped political contacts with Russia, but the content of these contacts has become significantly poorer, the format has narrowed, and the tone has sharpened. In the military sphere, Europe in the Russian direction follows in principle the same course as the United States. Within the framework of NATO, European countries, led by the United States, have taken a number of steps that have restored, so far at a symbolic level, the military confrontation with Russia in eastern Europe. Moscow, for its part, has stepped up its own military activities near its western borders. As a result, Europe has ceased to be the island of security that it remained for the previous quarter of a century. This does not mean, of course, that relations between Russia and European countries are ending. In fact, Russia's practical needs require easing tensions with Europe as its largest trade and economic partner. With this in mind, Moscow has achieved some success in replacing the almost non-existentties with Brussels with meaningful bilateral relations with some EU countries. Despite the fact that the European Union's foreign policy apparatus is unable to form a unified geopolitical, economic and cultural front against Moscow, there is every reason to believe that the Kremlin intends to be guided by this strategy of bilateral relations in the coming years.

NH3 as a Transport Fuel in Internal Combustion Engines: A Technical Review

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Herry Lesmana ◽  
Zhezi Zhang ◽  
Xianming Li ◽  
Mingming Zhu ◽  
Wenqiang Xu ◽  
...  
Keyword(s):  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Nox Formation ◽  
Combustion Chemistry ◽  
Technical Review ◽  
Current State ◽  
Potential Applications ◽  
Homogenous Charge Compression Ignition

Ammonia (NH3) is an excellent hydrogen (H2) carrier that is easy to bulk manufacture, handle, transport, and use. NH3 is itself combustible and could potentially become a clean transport fuel for direct use in internal combustion engines (ICEs). This technical review examines the current state of knowledge of NH3 as a fuel in ICEs on its own or in mixtures with other fuels. A particular case of interest is to partially dissociate NH3 in situ to produce an NH3/H2 mixture before injection into the engine cylinders. A key element of the present innovation, the presence of H2 is expected to allow easy control and enhanced performance of NH3 combustion. The key thermochemical properties of NH3 are collected and compared to those of conventional and alternative fuels. The basic combustion characteristics and properties of NH3 and its mixtures with H2 are summarized, providing a theoretical basis for evaluating NH3 combustion in ICEs. The combustion chemistry and kinetics of NH3 combustion and mechanisms of NOx formation and destruction are also discussed. The potential applications of NH3 in conventional ICEs and advanced homogenous charge compression ignition (HCCI) engines are analyzed.

Optimization of the Charge Motion in Internal Combustion Engines Driven by Sewage Gas for CHP-Units

2017 ◽  
Author(s):  
Lucas Konstantinoff ◽  
Lukas Möltner ◽  
Martin Pillei ◽  
Thomas Steiner ◽  
Thomas Dornauer ◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Engine Performance ◽  
Internal Combustion ◽  
Optical Methods ◽  
Combustion Engines ◽  
Charge Motion ◽  
Combustion Analysis ◽  
Valve Seat ◽  
Test Engine ◽  
Indication System

In this study, the influence of the charge motion on the internal combustion in a spark ignition sewage gas-driven engine (150 kW) for combined heat and power units was investigated. For this purpose, the geometry of the combustion chamber in the immediate vicinity to the inlet valve seats was modified. The geometrical modification measures were conducted iteratively by integrative determination of the swirl motion on a flow bench, by laser-optical methods and consecutively by combustion analysis on a test engine. Two different versions of cylinder heads were characterized by dimensionless flow and swirl numbers prior to testing their on-engine performance. Combustion analysis was conducted with a cylinder pressure indication system for partial and full load, meeting the mandatory NOx limit of 500 mg m−3. Subsuming the flow bench results, the new valve seat design has a significant enhancing impact on the swirl motion but it also leads to disadvantages concerning the volumetric efficiency. A comparative consideration of the combustion rate delivers that the increased swirl motion results in a faster combustion, hence in a higher efficiency. In summary, the geometrical modifications close to the valve seat result in increased turbulence intensity. It was proven that this intensification raises the ratio of efficiency by 1.6%.

FOREWORD

Geophysics ◽  
1964 ◽  
Vol 29 (2) ◽  
pp. 151-153 ◽  
Author(s):  
Charles C. Bates
Keyword(s):  
Prime Minister ◽  
State Of The Art ◽  
The United States ◽  
The Political ◽  
Bad Faith ◽  
Political Leaders ◽  
The Past ◽  
Current State ◽  
Nuclear Tests ◽  
Test Ban

A decade ago, it would have been the rare geophysicist indeed who would have predicted that his specialty was destined to become a major topic of discussion between such world political leaders as Presidents Eisenhower and Kennedy, Prime Minister Macmillan of Great Britain, and Chairman Khrushchev of the USSR. Yet this has come to pass during the past six years, for in 1958 there started the continuing round of international negotiations directed towards the creation of an effective underground test-ban treaty. During the conduct of these negotiations, it has been repeatedly necessary to assess the current state-of-the-art in seismology and its sister geophysical sciences, for the only detectable signals known to propagate for several hundreds to thousands of miles from underground nuclear tests are seismic in nature. With the United States policy being only to seek an underground-test-ban agreement incorporating strong safeguards against acts of bad faith, it is important that the political safe-guards be backed up by those of a geophysical nature.

Effect of Fuel Injection Pressure and Engine Speed on Performance, Emissions, Combustion, and Particulate Investigations of Gasohols Fuelled Gasoline Direct Injection Engine

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Nikhil Sharma ◽  
Avinash Kumar Agarwal
Keyword(s):  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Driving Forces ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Gasoline Direct Injection ◽  
Primary Alcohols ◽  
Renewable Fuel

Abstract Fuel availability, global warming, and energy security are the three main driving forces, which determine suitability and long-term implementation potential of a renewable fuel for internal combustion engines for a variety of applications. Comprehensive engine experiments were conducted in a single-cylinder gasoline direct injection (GDI) engine prototype having a compression ratio of 10.5, for gaining insights into application of mixtures of gasoline and primary alcohols. Performance, emissions, combustion, and particulate characteristics were determined at different engine speeds (1500, 2000, 2500, 3000 rpm), different fuel injection pressures (FIP: 40, 80, 120, 160 bars) and different test fuel blends namely 15% (v/v) butanol, ethanol, and methanol blended with gasoline, respectively (Bu15, E15, and M15) and baseline gasoline at a fixed (optimum) spark timing of 24 deg before top dead center (bTDC). For a majority of operating conditions, gasohols exhibited superior characteristics except minor engine performance penalty. Gasohols therefore emerged as serious candidate as a transitional renewable fuel for utilization in the existing GDI engines, without requirement of any major hardware changes.

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.

Science in Relation to Regulating and Promoting Civil Aviation

1929 ◽  
Vol 33 (228) ◽  
pp. 1139-1166
Keyword(s):  
Similar Condition ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Air Transport ◽  
Civil Aviation ◽  
Combustion Engines ◽  
The Past ◽  
Mechanical Devices ◽  
Physical Laws ◽  
Made In

During the past quarter of a century great strides have been made in perfecting the science of aviation. Too much credit cannot be given to the men who have laboured untiringly in the laboratories in an endeavour to determine with mathematical certainty the physical laws that govern the mechanical devices which mankind is using in his conquest of the air.Science has done more for civil aviation, however, than unravel the mysteries of aerodynamics and internal combustion engines. It has provided many important aids to air navigation, such as improved lighting facilities for airways and airports, wireless as a means of communication between ground and aeroplane, and also as a beacon to guide the pilot on his course, and numerous instruments which now adorn the cockpit of every aeroplane.While at times the development of air transport may suffer because of lack of co–ordination between the laboratory and the factory, it will suffer far more should a similar condition exist between the scientists and those charged with the duty of regulating and promoting civil aviation.

Exhaust System Gas-Dynamics in Internal Combustion Engines

2006 ◽  
Author(s):  
R. Pearson ◽  
M. Bassett ◽  
P. Virr ◽  
S. Lever ◽  
A. Early
Keyword(s):  
Gas Dynamics ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Exhaust System ◽  
Combustion Engines ◽  
Cycle Simulation ◽  
Model Following ◽  
Analytical Tools ◽  
Empirical Approaches ◽  
Engine Cycle

The sensitivity of engine performance to gas-dynamic phenomena in the exhaust system has been known for around 100 years but is still relatively poorly understood. The nonlinearity of the wave-propagation behaviour renders simple empirical approaches ineffective, even in a single-cylinder engine. The adoption of analytical tools such as engine-cycle-simulation codes has enabled greater understanding of the tuning mechanisms but for multi-cylinder engines has required the development of accurate models for pipe junctions. The present work examines the propagation of pressure waves through pipe junctions using shock-tube rigs in order to validate a computational model. Following this the effects of exhaust-system gas dynamics on engine performance are discussed using the results from an engine-cycle-simulation program based on the equations of one-dimensional compressible fluid flow.

scholarly journals Camshaftless Technology on Internal Engines

2020 ◽  
Vol 5 (2) ◽  
pp. 118-123
Author(s):  
Van Viet Pham
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Control Valve ◽  
Internal Combustion ◽  
Exhaust Valve ◽  
Combustion Engines ◽  
Toothed Belt ◽  
Significant Performance ◽  
Exhaust Valves

Along with the development of internal combustion engines, camshafts have also been developed to optimize engine performance. In all types of internal combustion engines, the crankshaft is connected to the camshaft via a toothed belt, chain or pinion. When the crankshaft turns, the camshaft spins and opens and closes the intake and exhaust valve respectively. However, in this non-camshaft engine technology, each intake and exhaust valve will be integrated with an electronically controlled hydraulic pump unit. This system provides a unique ability to independently control intake and exhaust valves. For any engine load, load and discharge times can be programmed independently. The decision system is based on driving conditions, used to maximize performance or minimize fuel consumption and emissions. This allows a greater degree of control over the engine which in turn provides significant performance benefits. This article presents reviews of camshaftless technology developed by VALEO. It is a system that uses solenoid valves to open and close the valve. The solenoid valve will be mounted right on top of the valve inside the engine. The author can see that the technology using this electronic control valve will help reduce the fuel consumption of the engine.

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