scholarly journals New methods in optical diagnostics on production engines with only minor modifications

2009 ◽  
Vol 137 (2) ◽  
pp. 50-61
Author(s):  
Werner HENTSCHEL
Keyword(s):  
Cylinder Head ◽  
High Speed ◽  
Laser Diagnostics ◽  
Direct Injection ◽  
Combustion Process ◽  
Green Light ◽  
Cylinder Liner ◽  
Optical Diagnostics ◽  
Experimental Investigations ◽  
Optical Probes

The aim of this paper is to demonstrate the performance of micro-invasive optical diagnostics as advanced tools in the development process of modern direct-injection (DI) gasoline engines. The use of endoscopes and optical probes minimise the mechanical modifications on the engine necessary to achieve the optical access to the combustion chamber. No expensive optical engines with large optical windows are required but only small holes of about 10 mm in the cylinder head or in a plate between cylinder head and cylinder liner are used to apply laser diagnostics. Basic in-cylinder phenomena, such as the formation of the flow field, the penetration of the spray at high fuel pressure, the interaction of spray and flow, the formation of an ignitable mixture and the start of combustion are analysed in detail. High-power solid-state pulsed lasers emitting ultraviolet or green light, state-of the-art high-speed colour video cameras, and newly designed optical probes were used for the investigations. Selected results from current research and development work demonstrate the capability of micro-invasive techniques and pinpoint how the design of the combustion process benefits from these experimental investigations.

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.

Multi-Valve High-Speed Direct Injection Diesel Engines—the Design Challenge

1993 ◽  
Vol 207 (4) ◽  
pp. 307-315
Author(s):  
I P Gilbert ◽  
A R Heath ◽  
I D Johnstone
Keyword(s):  
Diesel Engine ◽  
Fuel Economy ◽  
Cylinder Head ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Selection Strategy ◽  
Design Challenge ◽  
Hsdi Diesel Engine ◽  
High Level

The need to increase power, to improve fuel economy and to meet stringent exhaust emissions legislation with a high level of refinement has provided a challenge for the design of a compact high-speed direct injection (HSDI) diesel engine. This paper describes various aspects of cylinder head design with particular consideration of layout and number of valves, valve actuation, port selection strategy, fuel injection systems and cylinder head construction.

scholarly journals Hot-fire testing of liquid oxygen/hydrogen single coaxial injector at high-pressure conditions with optical diagnostics

2019 ◽  
Author(s):  
D.I. Suslov ◽  
J.S. Hardi ◽  
B. Knapp ◽  
M. Oschwald
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Optical Diagnostics ◽  
Liquid Oxygen ◽  
Experimental Investigations ◽  
Rocket Engines ◽  
Chamber Length ◽  
Substantial Progress ◽  
Liquid Rocket ◽  
Coaxial Injector

Injector behavior is of utmost importance for the performance and stability of liquid rocket engines (LREs). A major problem is getting a highly efficient homogeneous mixture and effective chemical reaction of fuels at minimum chamber length. Despite substantial progress in numerical simulations, a need for experimental data at representative conditions for development and validation of numerical design tools still exists. Therefore, in the framework of the DLR-project “ProTau,” the authors have performed tests to create an extended data base for numerical tool validation for high-pressure liquid oxygen (LOx) / hydrogen combustion. During the experimental investigations, a windowed DLR subscale thrust chamber model “C” (designated BKC) has been operated over a broad range of conditions at reduced pressures of approximately 0.8 (4 MPa), 1 (5 MPa), and 1.2 (6 MPa) with respect to the thermodynamic critical pressure of oxygen. Liquid oxygen and gaseous hydrogen (GH2) have been injected through a single coaxial injector element at temperatures of ~ 120 and ~ 130 K, respectively. High-speed optical diagnostics have been implemented, including imaging of OH* emission and shadowgraph imaging at frequencies from 8 up to 10 kHz to visualize the flow field.

A New Predictive ID Model for Advanced High Speed Direct Injection Diesel Engines

2004 ◽  
Author(s):  
Lurun Zhong ◽  
Naeim A. Henein ◽  
Walter Bryzik
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Direct Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Injection System ◽  
Injection Timing ◽  
Common Rail Injection System ◽  
Common Rail Injection ◽  
Starting Conditions

Advance high speed direct injection diesel engines apply high injection pressures, exhaust gas recirculation (EGR), injection timing and swirl ratios to control the combustion process in order to meet the strict emission standards. All these parameters affect, in different ways, the ignition delay (ID) which has an impact on premixed, mixing controlled and diffusion controlled combustion fractions and the resulting engine-out emissions. In this study, the authors derive a new correlation to predict the ID under the different operating conditions in advanced diesel engines. The model results are validated by experimental data in a single-cylinder, direct injection diesel engine equipped with a common rail injection system at different speeds, loads, EGR ratios and swirl ratios. Also, the model is used to predict the performance of two other diesel engines under cold starting conditions.

Analysis of the Flame Structure in a Trapped Vortex Combustor Using Low and High-Speed OH-PLIF

2014 ◽  
Author(s):  
Pradip Xavier ◽  
Alexis Vandel ◽  
Gilles Godard ◽  
Bruno Renou ◽  
Frederic Grisch ◽  
...  
Keyword(s):  
High Speed ◽  
Laser Diagnostics ◽  
Flame Structure ◽  
Combustion Process ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Time Resolved ◽  
Lean Combustion ◽  
Stage Combustion ◽  
Trapped Vortex

Operating with lean combustion has led to more efficient “Low-NOx” burners but has also brought several technological issues. The burner design geometry is among the most important element as it controls, in a general way, the whole combustion process, the pollutant emissions and the flame stability. Investigation of new geometry concepts associating lean combustion is still under development, and new solutions have to meet the future pollutant regulations. This paper reports the experimental investigation of an innovative staged lean premixed burner. The retained annular geometry follows the Trapped Vortex Combustor concept (TVC) which operates with a two stage combustion chamber: a main lean flame (1) is stabilized by passing past a vortex shape rich-pilot flame (2) located within a cavity. This concept, presented in GT2012-68451 and GT2013-94704, seems to be promising but exhibits combustion instabilities in certain cases, then leading to undesirable level of pollutant emissions and could possibly conduct to serious material damages. No precise information have been reported in the literature about the chain of reasons leading to such an operation. The aim of this paper is to have insights about the main parameters controlling the combustion in this geometry. The flame structure dynamics is examined and compared for two specific operating conditions, producing an acoustically self-excited and a stable burner. Low and high-speed OH-PLIF laser diagnostics (up to 10 kHz) are used to have access to the flame curvature and to time-resolved events. Results show that the cavity jets location can lead to flow-field oscillations and a non-constant flame’s heat release. The associated flame structure, naturally influenced by turbulence is also affected by hot gases thermal expansion. Achieving a good and rapid mixing at the interface between the cavity and the main channel leads to a stable flame.

Analysis of the Combustion Process in a EURO III Heavy-Duty Direct Injection Diesel Engine

2002 ◽  
Vol 124 (3) ◽  
pp. 636-644 ◽  
Author(s):  
J. M. Desantes ◽  
J. V. Pastor ◽  
J. Arre`gle ◽  
S. A. Molina
Keyword(s):  
High Speed ◽  
Direct Injection ◽  
Combustion Process ◽  
Engine Performance ◽  
Injection Pressure ◽  
Pollutant Emissions ◽  
Injection Timing ◽  
Engine Operation ◽  
Operation Conditions ◽  
Representative Points

To fulfill the commitments of future pollutant regulations, current development of direct injection (DI) Diesel engines requires to improve knowledge on the injection/combustion process and the effect of the injection parameters and engine operation conditions upon the spray and flame characteristics and how they affect engine performance and pollutant emissions. In order to improve comprehension of the phenomena inherent to Diesel combustion, a deep experimental study has been performed in a single-cylinder engine with the main characteristics of a six-cylinder engine passing the EURO III legislation. Some representative points of the 13-mode engine test cycle have been considered modifying the nominal values of injection pressure, injection load, intake pressure, engine speed, and injection timing. The study combines performance and emissions experimental measurements together with heat release law (HRL) analysis and high-speed visualization. Controlling parameters for BSFC, NOx, and soot emissions are identified in the last part of the paper.

Gasoline and E85 Combustion Visualization and Particulate Matter Emission in a Production SIDI Engine With Optical Access

2013 ◽  
Author(s):  
Po-I Lee ◽  
Xiaoce Feng ◽  
Ming-Chia Lai
Keyword(s):  
Diffusion Flame ◽  
High Speed ◽  
Particle Number ◽  
Total Concentration ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Coolant Temperature ◽  
Injection Timing ◽  
Optical Access

The present study analyzes the relationship of diffusion flame and PM emission of pure gasoline (E0) and E85 in a spark-ignited direct injection engine at low coolant temperature with optical access on one side of combustion chamber for high speed visualization. Different operating conditions including injection timing, ignition timing, and air-fuel ratio (lambda) with two throttle positions (high and low load) are experimented with a high speed FTIR and an Engine Exhaust Particle Sizer (EEPS) to measure the engine-out emissions. The results show that fuel types and injection timing strongly impact particle size distribution, total concentration, and total mass of PM emission due to piston or cylinder liner wall-wetting. It is concluded that both E0 and E85 present diffusion flame with early injection timing, and the existence of diffusion flame seen in the images corresponds to higher particle mass; however, it does not necessarily represent higher particle number, which is also fuel dependent. In certain conditions, PM emission of E85 could be higher in terms of particle number.

1D Engine Simulation of a Small HSDI Diesel Engine Applying a Predictive Combustion Model

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
T. Cerri ◽  
A. Onorati ◽  
E. Mattarelli
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Numerical Approach ◽  
Operating Conditions ◽  
Combustion Model ◽  
Full Load ◽  
Partial Load

The paper analyzes the operations of a small high speed direct injection (HSDI) turbocharged diesel engine by means of a parallel experimental and computational investigation. As far as the numerical approach is concerned, an in-house 1D research code for the simulation of the whole engine system has been enhanced by the introduction of a multizone quasi-dimensional combustion model, tailored for multijet direct injection diesel engines. This model takes into account the most relevant issues of the combustion process: spray development, air-fuel mixing, ignition, and formation of the main pollutant species (nitrogen oxide and particulate). The prediction of the spray basic patterns requires previous knowledge of the fuel injection rate. Since the direct measure of this quantity at each operating condition is not a very practical proceeding, an empirical model has been developed in order to provide reasonably accurate injection laws from a few experimental characteristic curves. The results of the simulation at full load are compared to experiments, showing a good agreement on brake performance and emissions. Furthermore, the combustion model tuned at full load has been applied to the analysis of some operating conditions at partial load, without any change to the calibration parameters. Still, the numerical simulation provided results that qualitatively agree with experiments.

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