CFD simulation-based predesign of an advanced gas-diesel combustion concept

2021 ◽  
pp. 146808742110350
Author(s):  
Hubert Winter ◽  
Kevin Aßmus ◽  
Christoph Redtenbacher ◽  
Dimitar Dimitrov ◽  
Andreas Wimmer
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Diesel Combustion ◽  
Virtual Design ◽  
Engine Operation ◽  
Low Emission ◽  
Methane Slip

The greenhouse gas saving potential of using gaseous fuels with high methane content (e.g. natural gas) in internal combustion engines instead of conventional liquid fossil fuels (e.g. petrol, diesel) is considerable due to the comparatively low emission of carbon dioxide resulting from the low C/H ratio of methane. However, to fully exploit this potential, it is of utmost importance to keep methane slip at a very low level. In contrast to mixture aspirated gas engines and diesel-gas engines, the gas-diesel combustion concept avoids methane slip nearly completely since the gaseous fuel is directly injected into the combustion chamber at the end of the high-pressure phase of the engine cycle, resulting in mixing-controlled combustion with low emission of unburned hydrocarbons. An advanced high-speed large engine concept based on the gas-diesel combustion process was developed. An effective and reliable virtual design methodology was applied during the development of the concept. The methodology comprehensively combines 3D CFD and 1D simulation tools in the combustion concept predesign phase with experiments on a single-cylinder research engine in the concept validation phase. A major challenge in the virtual design of this dual fuel combustion process is the large number of degrees of freedom that result in particular from the use of a fully flexible combined gas/diesel injector. This paper describes in detail the role of 3D CFD simulation in this approach, which allows precise prediction of the optimal geometries and operating strategies for high-efficiency and low-emission engine operation.

CFD Modelling of the Effects of Injection Timing on the Combustion Process and Emissions in an HSDI Diesel Engine

2012 ◽  
Author(s):  
Raouf Mobasheri ◽  
Zhijun Peng
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Cfd Simulation ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection Timing ◽  
Cfd Modelling ◽  
Combustion Modeling ◽  
Pressure Trace ◽  
Hsdi Diesel Engine

High-Speed Direct Injection (HSDI) diesel engines are increasingly used in automotive applications due to superior fuel economy. An advanced CFD simulation has been carried out to analyze the effect of injection timing on combustion process and emission characteristics in a four valves 2.0L Ford diesel engine. The calculation was performed from intake valve closing (IVC) to exhaust valve opening (EVO) at constant speed of 1600 rpm. Since the work was concentrated on the spray injection, mixture formation and combustion process, only a 60° sector mesh was employed for the calculations. For combustion modeling, an improved version of the Coherent Flame Model (ECFM-3Z) has been applied accompanied with advanced models for emission modeling. The results of simulation were compared against experimental data. Good agreement of calculated and measured in-cylinder pressure trace and pollutant formation trends were observed for all investigated operating points. In addition, the results showed that the current CFD model can be applied as a beneficial tool for analyzing the parameters of the diesel combustion under HSDI operating condition.

scholarly journals Prechamber optimal selection for a two stage turbulent jet ignition type combustion system in CNG-fuelled engine

2019 ◽  
Vol 176 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Ireneusz PIELECHA ◽  
Wojciech BUESCHKE ◽  
Maciej SKOWRON ◽  
Łukasz FIEDKIEWICZ ◽  
Filip SZWAJCA ◽  
...  
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Optimization Methods ◽  
Turbulent Jet ◽  
Experimental Investigations ◽  
Combustion System ◽  
Two Stage ◽  
Lean Burn ◽  
High Speed Engine

Searching for further reduction of fuel consumption simultaneously with the reduction of toxic compounds emission new systems for lean-mixture combustion for SI engines are being discussed by many manufacturers. Within the European GasOn-Project (Gas Only Internal Combustion Engines) the two-stage combustion and Turbulent Jet Ignition concept for CNG-fuelled high speed engine has been proposed and thoroughly investigated where the reduction of gas consumption and increasing of engine efficiency together with the reduction of emission, especially CO2 was expected. In the investigated cases the lean-burn combustion process was conducted with selection of the most effective pre-combustion chamber. The experimental investigations have been performed on single-cylinder AVL5804 research engine, which has been modified to SI and CNG fuelling. For the analysis of the thermodynamic, operational and emission indexes very advanced equipment has been applied. Based on the measuring results achieved for different pre-chamber config-urations the extended methodology of polioptimization by pre-chamber selection and the shape of main chamber in the piston crown for proposed combustion system has been described and discussed. The results of the three versions of the optimization methods have been comparatively summarized in conclusions.

Realization of a Fully Optically Accessible Medium Speed Large Bore Engine Using a Fisheye Optic

2020 ◽  
Author(s):  
Stephan Karmann ◽  
Christian Friedrich ◽  
Maximilian Prager ◽  
Georg Wachtmeister
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Engine Operation ◽  
New Approach ◽  
Medium Speed ◽  
Starting Point ◽  
Nominal Load ◽  
Fire Engine

Abstract To address one of the main environmental concerns, the engine out emissions, an enhanced understanding of the combustion process itself is fundamental. Recent optical and laser optical measurement techniques provide a promising approach to investigate and optimize the combustion process regarding emissions. These measurement techniques are already quite common for passenger car and truck size engines and significantly contribute to their improvement. Transferring these measurement techniques to large bore engines from low to high speed is still rather more uncommon especially due to the bigger challenges caused by the engine size and thus much higher stability requirements and design effort for optical accessibility. To cover this new field of research a new approach for a medium speed large bore engine was developed using a fisheye optic mounted centrally in the cylinder head to design a fully optically accessible engine test bench. This new approach is detailed with a test setup layout and a stability concept consisting of cooling systems and the development of a suitable operation strategy based on simulation and experimental verification. The design of this single cylinder engine with 350mm bore and 440mm stroke providing 530kW nominal load at 750 rpm was tested up to 85% nominal load in skipped fire engine operation mode. The measurements of the flame chemiluminescence of a dual fuel combustion of the diesel gas type present proof of the feasibility of the new design as a starting point for future systematic studies on the combustion process of large bore engines.

scholarly journals The Use Of Microturbines as an Energy Converter For Motor Transport

2019 ◽  
Vol 8 (10) ◽  
pp. 2700-2703
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Motor Vehicles ◽  
Turbine Engine ◽  
Range Extender ◽  
Traction Motors

At this stage of the development of vehicles with a combined power plant, one of the areas of development is the study of the introduction of a low-power gas turbine engine, the so-called microturbine, as a converter of thermal energy into mechanical. This solution has numerous positive aspects related to its fuel consumption, small dimensions, high efficiency, as well as a number of performance indicators. In this case, the vehicle is also equipped with a high-speed generator with the goal of converting the mechanical energy of the microturbine into electrical energy. This ensures the microturbine operation in a given range on the characteristic of optimal fuel consumption. The article contains an analysis of the use of microturbine generators in vehicles; some constructive solutions are considered as well. An overview of vehicles with microturbine generators and their comparison with traditional internal combustion engines is given. The movement of the vehicle is carried out by one or several traction motors. More than ten developments of motor vehicles using the microturbine as an additional source of energy for vehicles with traction electric drive are already known in the world, including MiTRE (Microturbine Range Extender). Among such vehicles, one can name the Trolza "Ecobus" buses, Delta Hypercar supercar, Isuzu NPR trucks, Mack Truck, Kenworth.

Emissions Control From IC Engines Using Advanced Combustion Chamber Design

1993 ◽  
Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating ◽  
Andrew A. Pouring
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Combustion Engine ◽  
Effective Means ◽  
Combustion Process ◽  
Cost Effective ◽  
Internal Combustion ◽  
Geometry Design ◽  
Pollutants Emission

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an homogeneous-charged internal combustion engine having conventional flat piston and five other bowl-in-piston geometries. The code employed here uses the time marching procedure and solves the governing partial differential equations of multi-component chemically reactive flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that the piston geometry affects the local flame properties which subsequently influences the pollutants emission level. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.

The study of a tractor diesel engine operation on ethanol and rapeseed oil at various speed modes

Trudy NAMI ◽  
2022 ◽  
pp. 53-59
Author(s):  
A. N. Kozlov ◽  
M. I. Araslanov
Keyword(s):  
Diesel Engine ◽  
Rapeseed Oil ◽  
Power Plants ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Renewable Energy Sources ◽  
Comparative Method ◽  
Combustion Process ◽  
Engine Operation ◽  
Tractor Diesel

Introduction (problem statement and relevance). The depletion of oil fuels reserves and the steady growth of their consumption will require new solutions in the development of technologies based on renewable energy sources. The study of the possible alternative fuels use in internal combustion engines is a complex scientific task, including the research of the alternative fuels effect on the power plants operation efficiency.The purpose of the study was to obtain the speed characteristics of a diesel engine operating on ethyl alcohol and rapeseed oil.Methodology and research methods. An air-cooled with volumetric mixture formation tractor diesel engine of dimension 2Ch 10.5/12.0 was selected as an object of research. The study was carried out by a comparative method. To measure the speed characteristic a fixed cyclic fuel supply was applied after the engine reaching the nominal operating mode at a crankshaft speed of 1800 min-1 and an average effective pressure in the cylinder of 0.588 MPa. This approach, with the all-mode regulator of the fuel pump turned off, made it possible to identify the main regularities of intra-cylinder processes at different speed modes of engine operation.Scientific novelty and results. The article presents the bench tests results of a diesel engine operating at various speed modes on ethanol and rapeseed oil, and analyzes in detail the main indicators of the combustion process and the effective engine performance in comparison to the use of traditional fuel. The practical significance lies in the possibility of using the obtained results to improve the diesel engines operation on alternative renewable fuels.

Piston Geometry Design Effects on Combustion and Emission Characteristics

1991 ◽  
Author(s):  
Ashwani K. Gupta ◽  
Lu Jiang ◽  
Eugene L. Keating
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Combustion Engine ◽  
Effective Means ◽  
Combustion Process ◽  
Internal Combustion ◽  
Emission Characteristics ◽  
Geometry Design ◽  
Pollutants Emission

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an internal combustion engine having conventional flat piston and advanced piston geometries. The code employed the time marching procedure that solves the governing partial differential equations of multi-component chemically reactive fluid flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that both the piston geometry and inlet flow conditions affects the local flame properties which subsequently alters the pollutants emission levels. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for energy conservation and environmental pollution control.

Application of HFRT Methods to Diagnose the Technical Condition of High-Speed Marine Diesel Engines

2015 ◽  
Vol 236 ◽  
pp. 161-168
Author(s):  
Tomasz Lus
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Fuel Injection ◽  
Combustion Process ◽  
Technical Condition ◽  
Injection System ◽  
Engine Fuel ◽  
Naval Academy ◽  
Marine Diesel

The paper presents problems related to testing of the technical condition of high-speed marine diesel engines that are not equipped with indicated valves, as it is in the case of larger medium-and low-speed marine internal combustion engines. In this case, in assessment of technical condition of engine fuel injection system and valve gear system a vibration signals (in time / angle domain) analysis modified method called HFRT (High Frequency Resonance Technique) can be used. This method indirectly helps also to evaluate the fuel combustion process in the engine cylinders. The paper presents the theoretical basis of a modified HFRT method, physical implementation of the marine diesel engine system’s analyzer used for marine engines testing built at the Institute of Construction and Operation of Ships at Polish Naval Academy (PNA) in Gdynia. The paper also includes a description of the vibration signal processing methodology and examples of measurements made in the ships conditions for a few selected types of engines.

scholarly journals Assessment of Direct Injected Liquefied Petroleum Gas-Diesel Blends for Ultra-Low Soot Combustion Engine Application

2020 ◽  
Vol 10 (14) ◽  
pp. 4949
Author(s):  
Roberto Ianniello ◽  
Gabriele Di Blasio ◽  
Renato Marialto ◽  
Carlo Beatrice ◽  
Massimo Cardone
Keyword(s):  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
High Efficiency ◽  
Combustion Engine ◽  
Combustion Process ◽  
Experimental Tests ◽  
Liquefied Petroleum Gas ◽  
Ambient Conditions ◽  
Promising Alternative ◽  
Compression Ignition Engines

Technological and economic concerns correlated to fulfilling future emissions and CO2 standards require great research efforts to define an alternative solution for low emissions and highly efficient propulsion systems. Alternative fuel formulation could contribute to this aim. Liquefied petroleum gas (LPG) with lower carbon content than other fossil fuels and which is easily vaporized at ambient conditions has the advantage of lowering CO2 emissions and optimizing the combustion process. Liquefied petroleum gas characteristics and availability makes the fuel a promising alternative for internal combustion engines. The possible combination of using it in high-efficiency compression ignition engines makes it worth analyzing the innovative method of using LPG as a blend component in diesel. Few relevant studies are detectable in literature in this regard. In this study, two blends containing diesel and LPG, in volume ratios 20/80 and 35/65, respectively, were formulated and utilized. Their effects on combustion and emissions performance were assessed by performing proper experimental tests on a modern light-duty single-cylinder engine test rig. Reference operating points at conventional engine calibration settings were examined. A specific exhaust gas recirculation (EGR) parametrization was performed evaluating the LPG blends’ potential in reducing the smoke emissions at standard engine-out NOx levels. The results confirm excellent NOx-smoke trade-off improvements with smoke reductions up to 95% at similar NOx and efficiency. Unburnt emissions slightly increase, and to acceptable levels. Improvements, in terms of indicated specific fuel consumption (ISFC), are detected in the range of 1–3%, as well as the CO2 decrease proportionally to the mixing ratio.

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