Design and Flow Analysis of a Novel Optically Accessible Heavy Duty Diesel Research Engine

2011 ◽  
Author(s):  
Stephen Busch ◽  
Maurice Kleindienst ◽  
Christoph Dahnz ◽  
Uwe Wagner ◽  
Ulrich Spicher
Keyword(s):  
Quartz Glass ◽  
Soot Formation ◽  
Laser Sheet ◽  
Cylinder Liner ◽  
Operating Conditions ◽  
Optical Measurements ◽  
Heavy Duty ◽  
Glass Cylinder ◽  
Trade Offs ◽  
Heavy Duty Diesel

A new single-cylinder optically accessible heavy duty diesel engine has been conceived and constructed at the Institut fu¨r Kolbenmaschinen. Rather than being made from a quartz glass cylinder, the cylinder liner of this engine is modified with three round, flat optical access ports to facilitate laser-optical measurements within the combustion chamber. The flat optical surfaces prove less problematic than a quartz glass cylinder in terms of internal reflections, cleaning procedures, cost, and robustness. A specially adapted piston facilitates the passage of the laser sheet into the piston bowl and provides a view into the bowl at top dead center. Computational fluid dynamics (CFD) simulations were performed in order to estimate the effects of the optically necessary piston and cylinder liner modifications on in-cylinder flow and to compare the flow characteristics with those simulated for a non-modified engine. Emphasis is placed on turbulence behavior before top dead center. The trade-offs and limitations inherent in the modified piston design are discussed in this context. Further optical investigations with this engine will provide insight into the mixture formation and combustion processes. In particular, the soot formation and oxidation processes will be studied under realistic engine operating conditions.

scholarly journals Effect of Load on Close-Coupled Post-Injection Efficacy for Soot Reduction in an Optical Heavy-Duty Diesel Research Engine

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Jacqueline O’Connor ◽  
Mark Musculus
Keyword(s):  
High Efficiency ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Optical Measurements ◽  
Injection Timing ◽  
Post Injection ◽  
Heavy Duty ◽  
Wide Range ◽  
Main Injection ◽  
Heavy Duty Diesel

The use of close-coupled post injections is an in-cylinder soot-reduction technique that has much promise for high efficiency heavy-duty diesel engines. Close-coupled post injections, short injections of fuel that occur soon after the end of the main fuel injection, have been known to reduce engine-out soot at a wide range of engine operating conditions, including variations in injection timing, exhaust gas recirculation (EGR) level, load, boost, and speed. While many studies have investigated the performance of post injections, the details of the mechanism by which soot is reduced remains unclear. In this study, we have measured the efficacy of post injections over a range of load conditions, at constant speed, boost, and rail pressure, in a heavy-duty optically-accessible research diesel engine. Here, the base load is varied by changing the main-injection duration. Measurements of engine-out soot indicate that not only does the efficacy of a post injection decrease at higher engine loads, but that the range of post-injection durations over which soot reduction is achievable is limited at higher loads. Optical measurements, including the natural luminescence of soot and planar laser-induced incandescence of soot, provide information about the spatiotemporal development of in-cylinder soot through the cycle in cases with and without post-injections. The optical results indicate that the post injection behaves similarly at different loads, but that its relative efficacy decreases due to the increase in soot resulting from longer main-injection durations.

scholarly journals Effect of Load on Close-Coupled Post-Injection Efficacy for Soot Reduction in an Optical, Heavy-Duty Diesel Research Engine

2013 ◽  
Author(s):  
Jacqueline O’Connor ◽  
Mark P. B. Musculus
Keyword(s):  
High Efficiency ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Optical Measurements ◽  
Injection Timing ◽  
Post Injection ◽  
Heavy Duty ◽  
Wide Range ◽  
Main Injection ◽  
Heavy Duty Diesel

The use of close-coupled post injections of fuel is an in-cylinder soot-reduction technique that has much promise for high efficiency, heavy-duty diesel engines. Close-coupled post injections, short injections of fuel that occur soon after the end of the main fuel injection, have been known to reduce engine-out soot at a wide range of engine operating conditions, including variations in injection timing, EGR level, load, boost, and speed. While many studies have investigated the performance of post injections, the details of the mechanism by which soot is reduced remains unclear. In this study, we have measured the efficacy of post injections over a range of load conditions, at constant speed, boost, and rail pressure, in a heavy-duty, optically-accessible research diesel engine. Here, the base load is varied by changing the main-injection duration. Measurements of engine-out soot indicate that not only does the efficacy of a post injection decrease at higher engine loads, but that the range of post-injection durations over which soot reduction is achievable is limited at higher loads. Optical measurements, including natural luminescence of soot and planar laser-induced incandescence of soot, provide information about the spatio-temporal development of in-cylinder soot through the cycle in cases with and without post injections. The optical results indicate that the post injection behaves similarly at different loads, but that its relative efficacy decreases due to the increase in soot resulting from longer main-injection durations.

Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural Gas Spark Ignition

2018 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Fuel Injector ◽  
Heavy Duty ◽  
Lean Burn ◽  
Spark Timing ◽  
Heavy Duty Diesel

Increased utilization of natural-gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduce greenhouse-gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOx, CO, and HC emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing, engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late burn (including double-peak heat release rate) was observed for advanced spark timing. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3 %), moderate rate of pressure rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

Tribological assessment of NiCr, Al2O3/TiO2, and Cr3C2/NiCr coatings applied on a cylinder liner of a heavy-duty diesel engine

2020 ◽  
pp. 146808742093016
Author(s):  
Onur Biyiklioğlu ◽  
Mustafa Ertunc Tat
Keyword(s):  
Cast Iron ◽  
Diesel Engine ◽  
Wear Rate ◽  
Gray Cast Iron ◽  
Cylinder Liner ◽  
Gray Cast ◽  
Economic Evaluations ◽  
Heavy Duty ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Internal combustion engines consume about 90% of fuel refined from crude oil which supplies 30% of the annual global flow of energy. Heavy-duty diesel engines are the primary source of power used in highways, marine, railroads, and power stations. The right coating can improve the tribological properties of cylinder liners and increase the mechanical efficiency of an engine. Also, it can help to extend the maintenance periods, and enhance the reliability of the vehicles. In this research, tribological and economic evaluations were performed for coated and uncoated substrates from a cylinder liner of a heavy-duty diesel engine, aiming to lower friction, wear rate, and maintenance cost. A reciprocating friction test was conducted under dry condition using Wolfram carbide (tungsten carbide) ball applied a 10 N normal load on a ball on disk geometry. The cylinder liner was made of gray cast iron, and the substrates obtained were coated with three different coating materials (Cr3C2/NiCr, NiCr, and Al2O3/TiO2) through the thermal spray and high-velocity oxy-fuel coating process. Tribological evaluations showed that the substrates coded with Al2O3/TiO2 and Cr3C2/NiCr had the lowest friction coefficient and wear rate. The most economical coating was Al2O3/TiO2, being able to supply about 61% lower coefficient of friction and 94% less wear rate relative to the uncoated sample, for the price of one-third of the Cr3C2/NiCr coating and one half of a new gray cast iron cylinder liner.

Speciation of Heavy Duty Diesel Exhaust Emissions under Steady State Operating Conditions

1996 ◽  
Author(s):  
Mridul Gautam ◽  
Deepak Gupta ◽  
Laila EI-Gazzar ◽  
Donald W. Lyons ◽  
Sriram Popuri
Keyword(s):  
Steady State ◽  
Diesel Exhaust ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Heavy Duty Diesel

Lean-Burn Characteristics of a Heavy-Duty Diesel Engine Retrofitted to Natural-Gas Spark Ignition

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Fuel Injector ◽  
Heavy Duty ◽  
Lean Burn ◽  
Heavy Duty Diesel ◽  
Ci Engines

Increased utilization of natural gas (NG) in the transportation sector can decrease the use of petroleum-based fuels and reduced greenhouse gas emissions. Heavy-duty diesel engines retrofitted to NG spark ignition (SI) can achieve higher efficiencies and low NOX, CO, and hydrocarbon (HC) emissions when operated under lean-burn conditions. To investigate the SI lean-burn combustion phenomena in a bowl-in-piston combustion chamber, a conventional heavy-duty direct-injection CI engine was converted to SI operation by replacing the fuel injector with a spark plug and by fumigating NG in the intake manifold. Steady-state engine experiments and numerical simulations were performed at several operating conditions that changed spark timing (ST), engine speed, and mixture equivalence ratio. Results suggested a two-zone NG combustion inside the diesel-like combustion chamber. More frequent and significant late-burn (including double-peak heat release rate) was observed for advanced ST. This was due to the chamber geometry affecting the local flame speed, which resulted in a faster and thicker flame in the bowl but a slower and thinner flame in the squish volume. Good combustion stability (COVIMEP < 3%), moderate rate of pressure-rise, and lack of knocking showed promise for heavy-duty CI engines converted to NG SI operation.

Thermo-Mechanical Fatigue Life Prediction of a Heavy Duty Diesel Engine Liner

2007 ◽  
Author(s):  
Amir Malakizadi ◽  
Hamidreza Chamani ◽  
Seyed Navid Shahangian ◽  
Seyed Ali Jazayeri ◽  
Iraj Sattarifar
Keyword(s):  
Kinematic Model ◽  
Combustion Process ◽  
Cylinder Liner ◽  
Experimental Results ◽  
Lifetime Prediction ◽  
Specific Power ◽  
Heavy Duty ◽  
Liner Material ◽  
Mechanical Fatigue ◽  
Heavy Duty Diesel

Engine designers are increasingly using more advanced simulation techniques to reduce design time and costs and at the same time to improve the accuracy of the work to limit the number of validation tests required. In recent years, the demand for higher specific power has enforced higher operating temperatures in engine parts, so thermo-mechanical fatigue (TMF) analysis is becoming more important. Liners are one of the challenging parts in heavy duty diesel engines which are exposed to high temperature differential between cooling jacket and combustion chamber and also they are in frictional contact with piston rings, therefore liners are subjected to complicated multiaxial thermal and mechanical stresses. In this study, a detailed analysis is conducted on a centrifugal gray cast iron liner using different CAE tools to have a more accurate estimate of thermo-mechanical loads. The coolant flows inside the liner jacket and combustion process within the cylinder are simulated using 3D CFD methods. Besides the linear FE analysis which is known as an oversimplified method, a multilinear kinematic model is used to simulate the material response more accurately. Using experimental results obtained from cylinder liner material, the different TMF approaches have been investigated and the differences between linear and nonlinear FE simulation in lifetime prediction have been revealed. It is shown that modified Manson-Coffin criterion is the promising relation for lifetime prediction of liner material that correlate better with experimental results.

Sign in / Sign up

Export Citation Format

Share Document