Optimal Linkage Design for Bicycle Power Transmission Using Symmetric Four-Bar

2006 ◽  
Author(s):  
Carl A. Nelson
Keyword(s):  
Internal Combustion Engines ◽  
Power Transmission ◽  
State Of The Art ◽  
Mechanical Efficiency ◽  
Substantial Improvement ◽  
Combustion Engines ◽  
Force Transmission ◽  
Linkage Design ◽  
Potential Applications ◽  
Four Bar Linkage

Use of a symmetric crank-rocker four-bar linkage is presented as an alternative to the standard bicycle crank. With the coupler being the driven link, a kinematic and force-transmission analysis is presented. Results of constrained nonlinear optimization for geometric synthesis show a substantial improvement in mechanical efficiency compared to the state of the art. Dead-center positions are also eliminated. Potential applications to other linear-to-rotary power transmission devices, such as internal-combustion engines, are also discussed.

A Generalized Compressor Power Model for Turbocharged Internal Combustion Engines With Reduced Complexity

2016 ◽  
Author(s):  
Tao Zeng ◽  
Devesh Upadhyay ◽  
Harold Sun ◽  
Guoming G. Zhu
Keyword(s):  
Internal Combustion Engines ◽  
Ad Hoc ◽  
Power Transmission ◽  
Internal Combustion ◽  
Mechanical Efficiency ◽  
Combustion Engines ◽  
Proposed Model ◽  
Adequate Accuracy ◽  
Compressor Power ◽  
Isentropic Efficiency

Control-oriented models of automotive turbocharger compressors typically describe the compressor power assumming an isentropic thermodynamic process with a fixed isentropic efficiency and a fixed mechanical efficiency for power transmission between the turbine and compressor. Although these simplifications make the control model tractable, they also introduce additional errors due to unmodeled dynamics, especially when the turbocharger is operated outside its normal operational region. This is also true for map-based approaches, since these supplier-provided maps tend to be sparse or incomplete at the boundary operational regions and often ad-hoc extrapolation is required, leading to large modeling error. Furthermore, these compressor maps are obtained from the steady flow bench tests, which introduce additional errors under pulsating flow conditions in the context of internal combustion engines. In this paper, a physics-based model of compressor power is developed using Euler equations for turbomachinery, where the mass flow rate and compressor rotational speed are used as model inputs. Two new coefficients, speed and power coefficients are defined. This makes it possible to directly estimate the compressor power over the entire compressor operating range based on a single analytic relationship. The proposed modeling approach is validated against test data from standard turbocharger flow bench, steady state engine dynamometer as well as transient simulation tests. The validation results show that the proposed model has adequate accuracy for model-based control design and also reduces the dimension of the parameter space typically needed to model the compressor dynamics.

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.

Tri-Axial Force Measurements on the Cylinder of a Motored SI Engine Operated on Lubricants of Differing Viscosity

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Bryan O’Rourke ◽  
Donald Radford ◽  
Rudolf Stanglmaier
Keyword(s):  
Axial Force ◽  
Internal Combustion Engines ◽  
Axial Direction ◽  
Internal Combustion ◽  
Mechanical Efficiency ◽  
Combustion Engines ◽  
Friction Characteristics ◽  
Colorado State University ◽  
And Performance ◽  
Lubricant Viscosity

Friction is a determining factor in the efficiency and performance of internal combustion engines. Losses in the form of friction work typically account for 10–20% of an engine’s output. Improvements in the friction characteristics of the power cylinder assembly are essential for reducing total engine friction and improving the mechanical efficiency of internal combustion engines. This paper describes the development and implementation of a new concept of the “floating liner” engine at Colorado State University that allows 0.5 crank angle deg resolved measurement of the forces on the cylinder along three axes—in the axial direction, the thrust direction, and along the wrist pin. Three different lubricants with differing properties were tested to observe the friction characteristics of each. The experimental results showed that the floating liner engine was able to resolve changes in friction characteristics coinciding with changes in lubricant viscosity and temperature. The axial force increases at TDC and BDC were observed as lubricant viscosity was decreased and larger amounts of mixed and boundary lubrication began to occur. For each test the axial friction force data was used to calculate total cycle friction work. The thrust and off-axis (wrist pin direction) forces are discussed under the same circumstances.

scholarly journals Enhancing the Efficiency of Gasoline Engines using Solar Powered Supercharger

2020 ◽  
Vol 8 (6) ◽  
pp. 1980-1983
Keyword(s):  
Renewable Energy ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Clean Energy ◽  
Mechanical Efficiency ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gasoline Engines ◽  
Fuel Prices ◽  
Solar Powered

The world presently depends heavily on nonrenewable sources of energy like crude oils. These conventional energy sources have certain limitations, that is, they will eventually run out, fuel prices can rise without warning and most importantly growing environmental concerns over the climate change associated with the release of CO2 on burning fossil fuels[1]. Renewable energy is the key to a clean energy future. In the last few decades, solar energy is the fastest growing renewable energy source[2]. We can harness this energy of the sun in increasing the efficiency of our automobiles. Forced induction system (supercharger and turbocharger) in automobiles helps in the improvement of the efficiency of internal combustion engines by pushing extra atmospheric air into the cylinder which results in the proper combustion of fuel and thus reducing the smoke from the exhaust gas. Conventional Supercharger draws power from the engine and though the overall mechanical efficiency is increased but some energy is lost in powering the supercharger. The main purpose of this paper is to develop a solar-powered supercharger which will not consume extra power from the engine and thus increase the overall efficiency of the engine along with a reduction in CO2 emission.

scholarly journals Lean-burn CNG engine with ignition chamber: from the idea to a running engine

2019 ◽  
Vol 176 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Michael WEIßNER ◽  
Frank BEGER ◽  
Martin SCHÜTTENHELM ◽  
Gunesh TALLU
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
State Of The Art ◽  
Combustion Engines ◽  
Lean Burn ◽  
Compressed Natural Gas ◽  
Emission Regulations ◽  
Cng Engine ◽  
Funded Project ◽  
The Eu

Current and further developing CO2- and emission regulations worldwide and the competition to full electric mobility deliver a chal-lenge for internal combustion engines in general. A state of the art solution is the use of natural gas mainly contending methane to reduce CO2 significantly and to offer lowest emission levels. The EU-funded project GasOn developed engine concepts to fully exploit the advantages of CNG. This article describes the development of an innovative, monovalent engine dedicated to Compressed Natural Gas (CNG) and characterised by the lean burn concept and the innovative pre-chamber combustion.

Tri-Axial Force Measurements on the Cylinder of a Motored SI Engine Operated on Lubricants of Differing Viscosity

2009 ◽  
Author(s):  
Bryan O’Rourke ◽  
Donald Radford ◽  
Rudolf Stanglmaier
Keyword(s):  
Axial Force ◽  
Internal Combustion Engines ◽  
Axial Direction ◽  
Internal Combustion ◽  
Mechanical Efficiency ◽  
Combustion Engines ◽  
Friction Characteristics ◽  
Colorado State University ◽  
And Performance ◽  
Lubricant Viscosity

Friction is a determining factor in the efficiency and performance of internal combustion engines. Losses in the form of friction work typically account for 10–20% of an engine’s output. Improvements in the friction characteristics of the power cylinder assembly are essential for reducing total engine friction and improving the mechanical efficiency of internal combustion engines. This paper describes the development and implementation of a new concept of the ‘floating liner’ engine at Colorado State University that allows 0.5 crank angle degree resolved measurement of the forces on the cylinder along 3 axes — in the axial direction, the thrust direction, and along the wrist pin. Three different lubricants with differing properties were tested to observe the friction characteristics of each. Experimental results showed that the floating liner engine was able to resolve changes in friction characteristics coinciding with changes in lubricant viscosity and temperature. Axial force increases at TDC and BDC were observed as lubricant viscosity was decreased and larger amounts of mixed and boundary lubrication began to occur. For each test the axial friction force data was used to calculate total cycle friction work. The thrust and off-axis (wrist pin direction) forces are discussed under the same circumstances.

scholarly journals Concepts for Hydrogen Internal Combustion Engines and Their Implications on the Exhaust Gas Aftertreatment System

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8166
Author(s):  
Stefan Sterlepper ◽  
Marcus Fischer ◽  
Johannes Claßen ◽  
Verena Huth ◽  
Stefan Pischinger
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
State Of The Art ◽  
Internal Combustion ◽  
Specific Power ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Engine Operation ◽  
Aftertreatment System ◽  
Exhaust Gas Aftertreatment

Hydrogen as carbon-free fuel is a very promising candidate for climate-neutral internal combustion engine operation. In comparison to other renewable fuels, hydrogen does obviously not produce CO2 emissions. In this work, two concepts of hydrogen internal combustion engines (H2-ICEs) are investigated experimentally. One approach is the modification of a state-of-the-art gasoline passenger car engine using hydrogen direct injection. It targets gasoline-like specific power output by mixture enrichment down to stoichiometric operation. Another approach is to use a heavy-duty diesel engine equipped with spark ignition and hydrogen port fuel injection. Here, a diesel-like indicated efficiency is targeted through constant lean-burn operation. The measurement results show that both approaches are applicable. For the gasoline engine-based concept, stoichiometric operation requires a three-way catalyst or a three-way NOX storage catalyst as the primary exhaust gas aftertreatment system. For the diesel engine-based concept, state-of-the-art selective catalytic reduction (SCR) catalysts can be used to reduce the NOx emissions, provided the engine calibration ensures sufficient exhaust gas temperature levels. In conclusion, while H2-ICEs present new challenges for the development of the exhaust gas aftertreatment systems, they are capable to realize zero-impact tailpipe emission operation.

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