High-pressure crystallisation studies of biodiesel and methyl stearate

CrystEngComm ◽  
2019 ◽  
Vol 21 (30) ◽  
pp. 4427-4436
Author(s):  
X. Liu ◽  
C. L. Bull ◽  
A. K. Kleppe ◽  
P. J. Dowding ◽  
K. Lewtas ◽  
...  
Keyword(s):  
High Pressure ◽  
Combustion Chamber ◽  
Methyl Stearate ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Renewable Fuel ◽  
Pressure Injection ◽  
High Pressure Injection

The widespread use of biodiesel as a renewable fuel offers many potential advantages, but at the same time presents challenges for modern internal combustion engines, particularly for those that involve high-pressure injection of fuel into the combustion chamber.

A General Rezoning Technique for KIVA3V Internal Combustion Engines CFD Simulations

2010 ◽  
Author(s):  
Randy P. Hessel ◽  
Ettore Musu ◽  
Salvador M. Aceves ◽  
Daniel L. Flowers
Keyword(s):  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Ad Hoc ◽  
National Laboratory ◽  
Internal Combustion ◽  
Computational Time ◽  
Combustion Engines ◽  
Combustion Chambers ◽  
Time Step ◽  
Engine Cycle

A computational mesh is required when performing CFD-combustion modeling of internal combustion engines. For combustion chambers with moving pistons and valves, like those in typical cars and trucks, the combustion chamber shape changes continually in response to piston and valve motion. The combustion chamber mesh must then also change at each time step to reflect that change in geometry. The method of changing the mesh from one computational time step to the next is called rezoning. This paper introduces a new method of mesh rezoning for the KIVA3V CFD-combustion program. The standard KIVA3V code from Los Alamos National Laboratory comes with standard rezoners that very nicely handle mesh motion for combustion chambers whose mesh does not include valves and for those with flat heads employing vertical valves. For pent-roof and wedge-roof designs KIVA3V offers three rezoners to choose from, the choice depending on how similar a combustion chamber is to the sample combustion chambers that come with KIVA3V. Often, the rezoners must be modified for meshes of new combustion chamber geometries to allow the mesh to successfully capture change in geometry during the full engine cycle without errors. There is no formal way to approach these modifications; typically this requires a long trial and error process to get a mesh to work for a full engine cycle. The benefit of the new rezoner is that it replaces the three existing rezoners for canted valve configurations with a single rezoner and has much greater stability, so the need for ad hoc modifications of the rezoner is greatly reduced. This paper explains how the new rezoner works and gives examples of its use.

Thermophysical Properties of Working Substance and Heat Transfer in a Hydrogen Combustion Engine

2003 ◽  
Author(s):  
T. Shudo ◽  
H. Oka
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Heat Loss ◽  
Thermophysical Properties ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Spark Ignition ◽  
Hydrogen Combustion ◽  
Spark Ignition Engine ◽  
Combustion Engines

Hydrogen is a clean alternative to fossil fuels for internal combustion engines and can be easily used in spark-ignition engines. However, the characteristics of the engines fueled with hydrogen are largely different from those with conventional hydrocarbon fuels. A higher burning velocity and a shorter quenching distance for hydrogen as compared with hydrocarbons bring a higher degree of constant volume and a larger heat transfer from the burning gas to the combustion chamber wall of the engines. Because of the large heat loss, the thermal efficiency of an engine fueled with hydrogen is sometimes lower than that with hydrocarbons. Therefore, the analysis and the reduction of the heat loss are crucial for the efficient utilization of hydrogen in internal combustion engines. The empirical correlations to describe the total heat transferred from the burning gas to the combustion chamber walls are often used to calculate the heat loss in internal combustion engines. However, the previous research by one of the authors has shown that the widely used heat transfer correlations cannot be properly applied to the hydrogen combustion even with adjusting the constants in them. For this background, this research analyzes the relationship between characteristics of thermophysical properties of working substance and heat transfer to the wall in a spark-ignition engine fueled with hydrogen.

On-Board Fuel Property Identification Method Based on High-Pressure Common Rail Pressure Signal

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Junfeng Zhao ◽  
Junmin Wang
Keyword(s):  
High Pressure ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Common Rail ◽  
Combustion Engines ◽  
Rail Pressure ◽  
Fuel Property ◽  
Pressure Signal ◽  
Common Rail Pressure ◽  
Property Identification

This paper investigates the impact of fuel property variations on the common rail pressure fluctuation in high-pressure common rail (HPCR) system and explores the possibility of identifying the fuel types based on the measurement of rail pressure for internal combustion engines. Fluid transients, particularly the water hammer effect in a HPCR system, are discussed and the 1D governing equations are given. A typical HPCR system model is developed in GT-Suite with the injectors, three-plunger high-pressure pump, and pressure control valve being modeled in a relatively high level of detail. Four different fuels including gasoline, ethanol, diesel, and biodiesel are modeled and their properties including density, bulk modulus, and acoustic wave speed are validated against data in the literature. Simulation results are obtained under different conditions with variable rail pressures and engine speeds. To reduce the excessive rail pressure oscillation caused by multiple injections, only four main-injections are enabled in each engine revolution. The results show that the natural frequency of a common rail varies with the type of fuel filled in it. By applying the fast Fourier transform (FFT) to the pressure signal, the differences of fuel properties can be revealed in the frequency domain. The experiment validation is conducted on a medium-duty diesel engine, which is equipped with a typical HPCR system and piezo-electric injectors. Tests results are given for both pure No. 2 diesel and pure soybean biodiesel at different rail pressure levels and different engine speeds. This approach is proved to be potentially useful for fuel property identification of gasoline-ethanol or diesel-biodiesel blends on internal combustion engines.

scholarly journals Challenging Sensing Solutions Designed by Sensata Bulgaria

2017 ◽  
Vol 15 (4) ◽  
pp. 28-39
Author(s):  
A. Tanev ◽  
P. Mitsev ◽  
T. Lazarova
Keyword(s):  
High Pressure ◽  
Temperature Sensor ◽  
Internal Combustion Engines ◽  
Pressure Sensors ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Automotive Applications ◽  
Sensing Technology ◽  
Very High

Abstract This paper presents novel green automotive platinum sensing technology together with pressure sensors design principles and applications. In recent years, worldwide emissions legislation has been introduced and is rapidly becoming more stringent. With alternative vehicular propulsion methods far from becoming mainstream reality, leading automotive providers have intensified efforts in the direction of reducing the harmful footprint of their products. This is being accomplished via smaller, appropriately designed internal combustion engines, necessitating an increased and higher-performance sensor content per vehicle. This paper elaborates on temperature sensor application in automotive exhaust gas performance sensing and as well as pressure sensors in different challenging automotive applications with very high pressure levels.

Investigating the Origins of Cyclic Variability in Internal Combustion Engines Using Wall-Resolved Large Eddy Simulations

2021 ◽  
Author(s):  
Sicong Wu ◽  
Saumil S. Patel ◽  
Muhsin M. Ameen
Keyword(s):  
Energy Distribution ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Large Eddy Simulations ◽  
Combustion Engines ◽  
Large Eddy ◽  
Cylinder Flow

Abstract Modern internal combustion engines (ICE) operate at the ragged edge of stable operation characterized by high cycle-to-cycle variations (CCV). A key scientific challenge for ICE is the understanding, modeling, and control of CCV in engine performance, which can contribute to partial burns, misfire, and knock. The objective of the current study is to use high-fidelity numerical simulations to improve the understanding of the causes of CCV. Nek5000, a leading high-order spectral element, open source code, is used to simulate the turbulent flow in the engine combustion chamber. Multi-cycle, wall-resolved large-eddy simulations (LES) are performed for the General Motors (GM), Transparent Combustion Chamber (TCC-III) optical engine under motored operating conditions. The mean and root-mean-square (r.m.s.) of the in-cylinder flow fields at various piston positions are validated using PIV measurements during the intake and compression strokes. The large-scale flow structures, including the swirl and tumble flow patterns, are analyzed in detail and the causes for cyclic variabilities in these flow features are explained. The energy distribution across the different scales of the flow are quantified using one-dimensional energy spectra, and the effect of the tumble breakdown process on the energy distribution is examined. The insights from the current study can help us develop improved engine designs with reduced cyclic variabilities in the in-cylinder flow leading to enhanced engine performance.

Removing carbon deposits from parts of the combustion chamber of diesel engines

2021 ◽  
pp. 136-144
Author(s):  
Keyword(s):  
Combustion Chamber ◽  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Coke Deposition ◽  
Combustion Engines ◽  
Maximum Torque ◽  
Carbon Deposits ◽  
Before And After ◽  
Land Rover

The Leader4M apparatus for removing carbon deposition with the help of hydrogenair mixture in internal combustion engines was developed. The efficiency of this apparatus when cleaning the engine parts from carbonand coke deposition was proved. Power indicators of diesel engines of BMW X1 2.0 td and Land Rover Discovery 3.0 td were measured before and after cleaning the combustion chamber parts of these engines using the Leader4M installation. After cleaning the parts of these engines from carbon deposits using the Leader4M unit, the maximum power of the engines increased by 2.0–2.1 %, and the maximum torque of these engines increased by 0.2–1.8 %. Keywords internal combustion engines; diesel engine; diesel fuel; carbon formation; hydrogenair mixture

A Numerical Investigation of Combustion Chamber Geometry Effects on Natural Gas Direct Injection Properties in a SI Engine With Centrally Mounted Multi-Hole Injector

2012 ◽  
Author(s):  
Bijan Yadollahi ◽  
Masoud Boroomand
Keyword(s):  
Numerical Model ◽  
Natural Gas ◽  
Flow Field ◽  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Validity Of Results

Due to the vast resources of natural gas (NG), it has emerged as an alternative fuel for SI internal combustion engines in recent years. The need to have better fuel economy and less emission especially that of greenhouse gases has resulted in development of NG fueled engines. Direct injection of natural gas into the cylinder of SI internal combustion engines has shown great potential for improvement of performance and reduction of engine emissions especially CO2 and PM. Direct injection of NG into the cylinder of SI engines is rather new thus the flow field phenomena and suitable configuration of injector and combustion chamber geometry has not been investigated completely. In this study a numerical model has been developed in AVL FIRE software to perform investigation of direct natural gas injection into the cylinder of spark ignition internal combustion engines. In this regard, two main parts have been taken into consideration aiming to convert an MPFI gasoline engine to direct injection NG engine. In the first part of study multidimensional numerical simulation of transient injection process, mixing and flow field have been performed via different validation cases in order to assure the numerical model validity of results. Adaption of such a modeling was found to be a challenging task because of required computational effort and numerical instabilities. In all cases present results were found to have excellent agreement with experimental and numerical results from literature. In the second part, using the moving mesh capability, the validated model has been applied to methane injection into the cylinder of a direct injection engine. Five different piston head shapes have been taken into consideration in investigations. An inwardly opening multi-hole injector has been adapted to all cases. The injector location has been set to be centrally mounted. The effects of combustion chamber geometry have been studied on mixing of air-fuel inside cylinder via quantitative and qualitative representation of results. Based on the results, suitable geometrical configuration for a NG DI engine has been discussed.

scholarly journals INFLUENCE OF USING ALTERNATIVE TYPES OF FUEL ON CHARACTERISTICS OF WORKING PROCESSES OF INTERNAL COMBUSTION ENGINES

2018 ◽  
pp. 24-32 ◽  
Author(s):  
Sergei Pavlovich Glushkov ◽  
Victor Ivanovich Kochergin ◽  
Vasiliy Victorovich Krasnikov
Keyword(s):  
Combustion Chamber ◽  
Synthesis Gas ◽  
Internal Combustion Engines ◽  
Pressure Rise ◽  
Hydrocarbon Fuel ◽  
Internal Combustion ◽  
Intake Manifold ◽  
Combustion Engines ◽  
Combustion Heat ◽  
Working Processes

In application of alternative types of fuel it is necessary to consider the influence of changing specific heat of fuel combustion and a process of fuel supply on parameters of working processes and external characteristics of internal combustion engines. Besides, it is necessary to consider a possible emergence of backfires in the inlet pipeline and increasing concentration of nitrogen oxides as temperature raises in the combustion chamber. It is offered to consider the influence of changing the kinetics of fuel burning under the change of fuel-air mixture composition on the process of pressure rise in the combustion chamber and, therefore, on the speed and acceleration of the piston, size of an impulse of moving parts, parameters of irregularity of rotating speed and vibration loading of the engine. In terms of using hydrogenous synthesis gas, there has been carried out the analysis of possible influence of its main components on parameters of working process of the engine. The results of theoretical calculation of an increase of combustion heat of working mixture and of pilot testing prove an increase of combustion heat and decrease of total fuel consumption at different levels of feeding synthesis gas to the engine intake manifold. The need to observe a certain proportion of hydrogen supply relative to the main hydrocarbon fuel has been noted. The research results prove that changing characteristics of the fuel used leads to a change of a type of vibration load of the power unit.

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