The efficiency of combustion has a major impact on the performance and emission characteristics of a spark-ignited LPG (Liquified Petroleum Gas) engine. The shape of the combustion chamber determines the homogeneous charge intake velocity, which is crucial for the turbulent motion that encourages flame propagation and quickens combustion. It need the right amount of compression ratio, charge squish velocity and turbulent kinetic energy to sustain combustion and propel laminar flames. There are a number of names for the motion of the charge within the cylinder: swirl, squish, tumble and turbulence. All of these terms affect how air and fuel are mixed and burned. Piston shape affects in-cylinder motion, which in turn reduces fuel consumption and improves combustion characteristics. The shape of the piston quench zone has a substantial impact on the charge velocity inside the combustion chamber. The impact on charge motion was analyzed using computer modeling using STAR-CD on pentroof

Sagaya Raj, Gnana, R L, Krupakaran, Pasupuleti, Thejasree, Natarajan, Manikandan

Analysis of Injection Characteristics and Structural Reliability of Marine Methanol Fuel Injectors

2025-01-7116

01/31/2025

Nowadays, the energy transition is at the most critical moment. In order to achieve the emission reduction target of ships, a form of boosting piston inside methanol fuel injector has been carried out. The physical property fluctuations and phase change of methanol under high pressure have been considered in the design phase. 1D-3D coupling method is used to comprehensively evaluate the performace of the injector. To this end, an Amesim simulation model is established to systematically study and analyze the injection characteristics. The injection performance of the injector under four typical loads are calculated, which is evaluated from the perspectives of injection quantity, injection duration, valve response, and leakage of boost components. In the nozzle block, the cavitation intensity of methanol is stronger than that of diesel. To reduce the possibility of cavitation erosion, as a consequence, a CFD model is established to optimize the structure of nozzle components. By adding

Yang, Li, Wen, Liming, Zhang, Hanwen, Lu, Gangao, Dong, Weijie

Digital Twin-Enabled Fault Detection for Suspension Systems in Autonomous Mining Haulage Vehicles

2024-36-0170

12/20/2024

Autonomous vehicles for mining operations offer increased productivity, reduced total cost of ownership, decreased maintenance costs, improved reliability, and reduced operator exposure to harsh mining environments. A large flow of data exists between the remote operation and the ore haul vehicle, and part of the data becomes information for the maintenance sector which it monitors the operating conditions of various systems. One of the systems deserving attention is the suspension system, responsible for keeping the vehicle running and within a certain vibration condition to keep the asset operational and productive. Thus, this work aims to develop a digital twin-assisted system to evaluate the harmonic response of the vehicle’s body. Two representations were created based on equations of motion that modeled the oscillatory behavior of a mass-damper system. One of the representations indicates a quarter of the ore transport truck’s hydraulic system in a healthy state, called a virtual

Rosa, Leonardo Olimpio, Branco, César Tadeu Nasser Medeiros

Enhancing Diesel Engine Performance with Silica Coated Pistons and Cassia Fistula Biodiesel Blends: A Pathway to Cleaner and Efficient Energy

2024-01-5222

12/10/2024

This study investigates the influence of Silica-Diamond-Like Carbon (Si-DLC) coated pistons on performance metrics of diesel engine fuelled with various blends of Cassia Fistula biodiesel (CFBD10, CFBD20, CFBD30, and CFBD40). The primary focus is on key performance metrics, including Brake Thermal Efficiency (BTE), Brake Specific Energy Consumption (BSEC), and Exhaust Gas Temperature (EGT). The results demonstrated improvement in BTE and EGT, alongside a reduction in BSEC across all biodiesel blends compared to conventional diesel. Specifically, at full engine load, CFBD10 exhibited a BTE of 33.41%, which is 3.17% higher than neat diesel in the stock engine. At part load and no-load scenarios, improvements of 2% and 0.51% over neat diesel were recorded. During no-load conditions, the BSEC for CFBD10 was measured at 9.901 MJ.kW-hr, 0.738 MJ.kW-hr lower than that of neat diesel. Further increases in Cassia fistula blends resulted in higher BSEC values due to lower calorific content

Veeraraghavan, Sakthimurugan, De Poures, Melvin Victor, Madhu, S., Palani, Kumaran

Effect of Temperature on Aluminum Alloy (Al4032) Using Textured Surface

2024-28-0160

12/05/2024

The larger domain of surface texture geometry and other input variables related to engine operation, i.e., elevated temperature, has remained to be studied for finding suitable surface texture for real-time engine operations. In previous efforts to find suitable surface texture geometry and technique, the tribological performance of the piston material (Al4032) with dimples of varying diameters (90 to 240 μm) was evaluated under mixed and starved lubrication conditions in a pin-on-disk configuration. The disc was textured using a ball nose end mill cutter via conventional micromachining techniques. The area density and aspect ratio (depth to diameter) of the dimples were kept constant at 10% and 1/6, respectively. SAE 20W-40 oil was used as a lubricant with three separate drop volumes. The experiments were conducted in oscillating motion at temperatures of 50, 100 and 150°C. Conventional micromachining achieved improved dimensional precision and minimized thermal damage. Textured

Sahu, Vikas Kumar, Shukla, Pravesh Chandra, Gangopadhyay, Soumya

Multiphase Flow Simulation of Blow-by and Fuel-in-Oil Dilution via the Piston Ring Pack Using the Level-Set Method

04-18-01-0003

09/09/2024

Modern diesel engines temporarily use a very late post-injection in the combustion cycle to either generate heat for a diesel particulate filter regeneration or purge a lean NOx trap. In some configurations, unburned fuel is left at the cylinder walls and is transported via the piston rings toward the lower crankcase region, where fuel may dilute the oil. Reduced oil lubrication shortens the oil service intervals and increases friction. Beside diesel fuel, this problem may also occur for other types of liquid fuels such as alcohols and e-fuels. The exact transport mechanism of the unburned fuel via the piston ring pack grooves and cylinder wall is hard to measure experimentally, motivating numerical flow simulation in early design stages for an in-depth understanding of the involved processes. A new CFD simulation methodology has been developed to investigate the transient, compressible, multiphase flow around the piston ring pack, through the gap between piston and liner, and its

Antony, Patrick, Hosters, Norbert, Behr, Marek, Hopf, Anselm, Krämer, Frank, Weber, Carsten, Turner, Paul

Glow Discharge Optical Emission Spectroscopy Study of Cr(III) Sealing in Anodized Aluminum-Silicon Alloys

2024-01-3038

09/08/2024

The work investigates the penetration depth of a low environmental impact Cr(III)-based sealing on two anodized Aluminum-Silicon alloys (i.e., EN AC-42200 and EN AC-43200) for brake system applications. EN AC-42200 and EN AC-43200 specimens are: 1) obtained by sectioning of gravity cast components; 2) anodized using different process times to obtain different anodic layer thicknesses; and 3) sealed in a Cr(III)-based proprietary sealing solution at low temperature. The obtained sealed anodic layers are characterized using several techniques including: Glow Discharge Optical Emission Spectroscopy (GDOES), metallographic analyses and Eddy current thickness measurements. Results demonstrate that: a) the Cr(III) concentration within the anodic layers shows an exponentially decreasing trend from the specimen surface toward the anodic layer-substrate interface; b) the typical thickness of the sealing layer is in the order of 1.5μm; and c) the Cr(III) penetration depth is only marginally

Pavesi, Arianna, Fumagalli, Luca, Abello, Mary Angel, Bonfanti, Andrea, Mancini, Alessandro, Vedani, Maurizio, Bertasi, Federico

Piston and Guide-Pin Rattle Noise Mitigation in Electro-Mechanical Brake Caliper

2024-01-3032

09/08/2024

Brake caliper commonly utilizes rubber or spring components to maintain specific clearance range for sliding characteristics, rendering them susceptible to rattle noise. The Electro-Mechanical Brake (EMB) caliper has attracted attention for its advantageous features such as reduced brake drag, optimized vehicle layout, and precise brake control. However, the inclusion of additional components related to the dry-type pressurizing system results in increased caliper weight and susceptibility to rattle noise. This study thoroughly examines rattle noise characteristics in our prototype EMB caliper, identifying primary noise sources on the piston and guide-pin sides. Implementing piston seals and guide-pin boots tightening force proves the effectiveness in improving rattle noise characteristics. Collisions between the piston and ball-screw head can be mitigated by piston inner seal, significantly reducing rattle noise. The effectiveness of the piston outer seal is limited and can be

Yoon, Boram, Jeon, Kyeong Hun, Boo, Sangpil, Shin, Choongsik, Kim, Tae Hoon

A Computational Study of Hydrogen Direct Injection Using a Pre-Chamber in an Opposed-Piston Engine

2024-01-3010

07/02/2024

Combustion characteristics of a hydrogen (H2) direct-injected (DI) pre-chamber (PC)-assisted opposed piston two-stroke (OP2S) engine are investigated by 3D computational fluid dynamics (CFD) simulations. The architecture of the OP2S engine has potential features for reducing wall heat losses, as the DI H2 jets are not directed towards the piston face. To overcome the high resistance to autoignition of H2, a PC technology was implemented in order to enhance the ignition of the mixture by the multiple hot reactive jets. To further investigate the interaction between the H2 plume and the chamber walls, three different piston bowl designs were evaluated and ranked based on a merit function. For the cases under study, the flat piston design was found to be most favorable (compared to the narrow and wide pistons) due to its reduced surface area for lower wall heat losses. The results also showcase that a co-optimization approach considering various parameters is an effective strategy to

Menaca, Rafael, Moreno Cabezas, Kevin, Shakeel, Mohammad Raghib, Vorraro, Giovanni, Turner, James W. G., Im, Hong G.

Experimental Study of Lignin Fuels for CI Engines

2024-37-0022

06/12/2024

This study explores the feasibility of using a sustainable lignin-based fuel, consisting of 44 % lignin, 50 % ethanol, and 6 % water, in conventional compression ignition (CI) marine engines. Through experimental evaluations on a modified small-bore CI engine, we identified the primary challenges associated with lignin-based fuel, including engine startup and shutdown issues due to solvent evaporation and lignin solidification inside the fuel system, and deposit formation on cylinder walls leading to piston ring seizure. To address these issues, we developed a fuel switching system transitioning from lignin-based fuel to cleaning fuel with 85 vol% of acetone, 10 vol% of water and 5 vol% of ignition improving additive, effectively preventing system clogs. Additionally, optimizing injection parameters, adopting a constant pressure delivery valve, and fine-tuning injection timing mitigated lignin deposit formation related to incomplete combustion or spray tip penetration to the cylinder

Terauchi, Motoki, Simonsen, Tor, Mortensen, Simon, Schramm, Jesper, Ivarsson, Anders

Influences of High-Pressure Pump and Injector Nozzle Geometry on Hydraulics Characteristics of a Mechanical Diesel Direct-Injection System

2024-01-5061

06/04/2024

The geometry of high-pressure pump and injector nozzles crucially influences hydraulic behaviors (e.g., the start of injection, the pressure profiles developed in the high-pressure line, needle lift, and injection rates) in diesel engines. These factors, in turn, significantly impact fuel atomization, fuel–air mixing, combustion quality, and the formation of emissions. The main geometry parameters such as plunger diameter and the number and diameter of nozzles lead to the system complexity, requiring careful analysis, design, and calibration. In this study, a high-speed shadowgraph system and a high-resolution pressure recording system were developed to capture the start of injection, spray structure, and pressure profiles in the high-pressure line. Additionally, a model was developed using GT-Fuel package built within the GT-Suite of simulation tools to explore different plunger diameters and numbers and diameters of injector nozzles. These models were validated using the pressure

Nguyen, Quan Q., Vu, Manh D., Phung, Duoc V., Nguyen, Kien T., Vu*, Tuan N., Pham, Phuong X.

Evaluating the Effects of an Electrically Assisted Turbocharger on Scavenging Control for an Opposed Piston Two Stroke (OP2S) Compression Ignition Engine

2024-01-2388

04/09/2024

Opposed piston two-stroke (OP2S) diesel engines have demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Due to the higher stroke-to-bore ratio and the absence of a cylinder head, the heat transfer loss to the coolant is lower near ‘Top Dead Center.’ The selection and design of the air path is critical to realizing the benefits of the OP2S engine architecture. Like any two-stroke diesel engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Without dedicated pumping strokes, the two-stroke engine architecture requires external devices to breathe. In the unique OP2S engine architecture studied in this work, the external pumping devices present in the air path include an electrically assisted turbocharger (EAT), an electrified EGR pump, and a back-pressure valve (BPv) located downstream of the

Bhatt, Ankur, Gandolfo, John, Huo, Ming, Gainey, Brian, Lawler, Benjamin

Combustion Analysis of Hydrogen-DDF Mode Based on OH* Chemiluminescence Images

2024-01-2367

04/09/2024

Hydrogen–diesel dual-fuel combustion processes were visualized using an optically accessible rapid compression and expansion machine (RCEM). A hydrogen-air mixture was introduced into the combustion chamber, and a pilot injection of diesel fuel was used as the ignition source. A small amount of diesel fuel was injected as the pilot fuel at injection pressures of 40, 80, and 120 MPa using a common rail injection system. The injection amounts of diesel fuel were varied as 3, 6, and 13 mm3. The amount of hydrogen was manipulated by varying the total excess air ratio (λtotal) at 3 and 4. The RCEM was operated at a constant speed of 900 rpm, and the in-cylinder pressure and temperature at the top dead center (TDC) were set as 5 MPa and 700 K, respectively. The combustion processes were visualized via direct photography and hydroxyl (OH*) chemiluminescence photography using a high-speed camera and an image intensifier. The results indicated that the diesel mixture first ignited near the wall

Mukhtar, Ghazian Amin, Shimogawa, Koki, Horibe, Naoto, Hayashi, Jun, Kawanabe, Hiroshi, Morita, Gin, Hiraoka, Kenji

Effect of In-Cylinder Flow Motion on Fuel-Air Mixture Formation in a Medium-Duty DI-SI H2 Engine: An Experimentally Supported CFD Study

2024-01-2117

04/09/2024

The increased utilization of batteries and fuel-cells for powering electric applications, as well as bio- and e-fuels into internal combustion engines are seen as options to lower the carbon footprint of industry and transportation sectors. When high power outputs and fast refueling are requisites, H2 ICEs may be a relevant choice. Applications include electricity conversion within a genset or mechanical energy in a vehicle. Within this framework, a John Deere 4045 Diesel engine converted to a H2 single-cylinder is studied at relevant operating conditions for the mentioned use cases, which pose high torque and power output requirements. The modified engine integrates a Phinia DI-CHG 10 outward-opening H2 injector instead of the Diesel unit, as well as a spark-plug rather than the glow-plug. To explore the effects of in-cylinder air flow on the H2-air mixing, two piston designs are employed: one conserves the intake generated swirl; the other contains deflectors promoting a more complex

Mota Ferreira, João, Oung, Richard, Foucher, Fabrice

Ducted Fuel Injection: Confirmed Re-entrainment Hypothesis

2024-01-2885

04/09/2024

Testing of ducted fuel injection (DFI) in a single-cylinder engine with production-like hardware previously showed that adding a duct structure increased soot emissions at the full load, rated speed operating point [1]. The authors hypothesized that the DFI flame, which travels faster than a conventional diesel combustion (CDC) flame, and has a shorter distance to travel, was being re-entrained into the on-going fuel injection around the lift-off length (LOL), thus reducing air entrainment into the on-going injection. The engine operating condition and the engine combustion chamber geometry were duplicated in a constant pressure vessel. The experimental setup used a 3D piston section combined with a glass fire deck allowing for a comparison between a CDC flame and a DFI flame via high-speed imaging. CH* imaging of the 3D piston profile view clearly confirmed the re-entrainment hypothesis presented in the previous engine work. This finding suggests that a DFI retrofit for this

Svensson, Kenth, Fitzgerald, Russell, Martin, Glen

Investigation on Fuel Economy Benefits by Lubrication System Optimization for a High Performance 2.2 L Diesel Engine

2024-01-2415

04/09/2024

Lubrication systems play a major role not only in the durability of modern IC engines but also in performance and emissions. The design of the lubrication system influences the brake thermal efficiency of the engine. Also, efficient lubrication reduces the engine's CO2 emissions significantly. Thus, it is critical for an IC engine to have a well-designed lubrication system that performs efficiently at all engine operating conditions. The conventional lubrication system has a fixed-displacement oil pump that can cater to a particular speed range. However, a fully variable displacement oil pump can cater to a wide range of speeds, thereby enhancing the engine fuel efficiency as the oil flow rates can be controlled precisely based on the engine speed and load conditions. This paper primarily discusses the optimization of a lubrication system with a Variable Displacement Oil Pump (VDOP) and a map-controlled Piston Cooling Jet (PCJ) for a passenger car diesel engine. The drive ratio for the

Kulkarni, Shrihari, Dharan R, Bharani, Kawatkar, Amit, Sasikumar, M., Loganathan, S.

Engine Crank Stop Position Control to Reduce Starting Vibration of a Parallel Hybrid Vehicle

2024-01-2784

04/09/2024

Engine off control is conducted on parallel hybrid vehicles in order to reduce fuel consumption. It is efficient in terms of fuel economy, however, noise and vibration is generated on engine cranking and transferred through engine mount on every mode transition from EV to HEV. Engine crank position control has been studied in this paper in order to reduce vibration generated when next cranking starts. System modeling of an architecture composed of an engine, P1 and P2 motors has been conducted. According to the prior studies, there exists correlation between crank vibration level and the crank angle. Thus a method to locate pistons on a specific crank angle which results in a local minimum of vibration magnitude could be considered. The P1 motor facilitates this crank position control when engine turns off, for its location directly mounted on a crankshaft allows the system model to obtain more precise crank position estimation and improved linearity in torque control as well. For the

Park, Jihyun, Yang, Byunghoon, LIM, Jongkyong, Kim, SungKyu

Effect of Baffle Height on the in-Cylinder Air-Fuel Mixture Preparation in a Gasoline Direct Injection Engine – A Computational Fluid Dynamics Analysis

2024-01-2697

04/09/2024

In-cylinder fluid dynamics enhance performance and emission characteristics in internal combustion (IC) engines. Techniques such as helical ports, valve shrouding, masking, and modifications to piston profiles or vanes in ports are employed to achieve the desired in-cylinder flows in these engines. However, due to space constraints, modifications to the cylinder head are typically minimal. The literature suggests that introducing baffles into the combustion chamber of an IC engine can enhance in-cylinder flows, air-fuel mixing, and, subsequently, stratification. Studies have indicated that the height of the baffles plays a significant role in determining the level of improvement in in-cylinder flow and air-fuel mixing. Therefore, this study employs Computational fluid dynamics (CFD) analysis to investigate the impact of baffle height on in-cylinder flow and air-fuel mixing in a four-stroke, four-valve, spray-guided gasoline direct injection (GDI) engine. The maximum allowable baffle

V, Vishal, Mallikarjuna, J M

Piston Geometries Impact on Spark-Ignition Light-Duty Hydrogen Engine

2024-01-2613

04/09/2024

The European Union aims to be climate neutral by 2050 and requires the transport sector to reduce their emissions by 90%. The deployment of H2ICE to power vehicles is one of the solutions proposed. Indeed, H2ICEs in vehicles can reduce local pollution, reduce global emissions of CO2 and increase efficiency. Although H2ICEs could be rapidly introduced, investigations on hydrogen combustion in ICEs are still required. This paper aims to experimentally compare a flat piston and a bowl piston in terms of performances, emissions and abnormal combustions. Tests were performed with the help of a single cylinder Diesel engine which has been modified. In particular, a center direct injector dedicated to H2 injection and a side-mounted spark plug were installed, and the compression ratio was reduced to 12.7:1. Several exhaust gas measurement systems complete the testbed to monitor exhaust NOx and H2. Results were obtained for a specific operating point, 2000 rpm as engine speed and 13 bar as

Masurier, Jean-Baptiste, LOW-KAME, Jean, Oung, Richard, Foucher, Fabrice

Optimization of the IC Engine Piston Skirt Design Via Neural Network Surrogate and Genetic Algorithms

2024-01-2603

04/09/2024

Internal combustion (IC) engines still power most of the vehicles on road and will likely to remain so in the near future, especially for heavy duty applications in which electrification is typically more challenging. Therefore, continued improvements on IC engines in terms of efficiency and longevity are necessary for a more sustainable transportation sector. Two important design objectives for heavy duty engines with wet liners are to reduce friction loss and to lower the risks of cavitation damages, both of which can be greatly influenced by the piston-liner clearance and the design of the piston skirt. However, engine design optimization is difficult due to the nonlinear interactions between the key design variables and the design objectives, as well as the multi-physics and multi-scale nature of the mechanisms that are relevant to the design objectives. In this work, an efficient optimization method is proposed to optimize the piston skirt design and the piston-liner warm

Zhong, Xinlin, Yang, Tsung-Yu, Tian, Tian

Improving the Performance of Diesel Engines by Bore Profile Control under Operating Conditions

2024-01-2832

04/09/2024

The cylinder bore in an engine block is deformed under the assembling stress of the cylinder head and thermal stress. This distortion exacerbates the piston skirt friction and piston slap. Through a numerical and experimental study, this article analyzes the effect of an optimized bore profile on the engine performance. The piston skirt friction was estimated in a three-dimensional elastohydrodynamic (EHD) friction analysis. An ideal cylindrical bore under the rated load condition was assumed as the optimal bore profile that minimized the piston skirt friction without compromising the piston slap. The simulation study revealed that secondary motion of the piston immediately after firing the top dead center can be mitigated by narrowing the piston–bore clearance at the upper position of the cylinder. After optimizing the bore profile, enlarging the clearance from the middle to the lower part of the cylinder reduced the friction in the piston skirt to cylinder interface by an estimated

Hibi, Taiga, Mita, Takuro, Yamashita, Kenichi

Validation of a Two-Parameter Controlled Novel Tribometer for Analysing Durability of Piston Ring-Engine Cylinder Tribo-Pair

2024-01-2067

04/09/2024

The wear of the piston ring-cylinder liner system in gasoline engines is inevitable and significantly impacts fuel economy. Utilizing a custom-built linear reciprocating tribometer, this study assesses the wear resistance of newly developed engine cylinder coatings. The custom device offers a cost-effective means for tribological evaluation, optimizing coating process parameters with precise control over critical operational factors such as normal load and sliding frequency. Unlike conventional commercial tribometers, it ensures a more accurate simulation of the engine cylinder system. However, existing research lacks a comprehensive comparative analysis and procedure to establish precision limits for such modified devices. This study evaluates the custom tribometer's repeatability compared to a commercial wear-testing instrument, confirming its potential as a valuable tool for advanced wear testing on engine cylinder samples. The validation tests, achieved through standardized contact

Sediako, Dimitry G., Banerjee, Siddharth

Numerical Evaluation of Injection Parameters on Transient Heat Flux and Temperature Distribution of a Heavy-Duty Diesel Engine Piston

2024-01-2688

04/09/2024

A major concern for a high-power density, heavy-duty engine is the durability of its components, which are subjected to high thermal loads from combustion. The thermal loads from combustion are unsteady and exhibit strong spatial gradients. Experimental techniques to characterize these thermal loads at high load conditions on a moving component such as the piston are challenging and expensive due to mechanical limitations. High performance computing has improved the capability of numerical techniques to predict these thermal loads with considerable accuracy. High-fidelity simulation techniques such as three-dimensional computational fluid dynamics and finite element thermal analysis were coupled offline and iterated by exchanging boundary conditions to predict the crank angle-resolved convective heat flux and surface temperature distribution on the piston of a heavy-duty diesel engine. A Bayesian calibration method was used to arrive at heat transfer coefficients for some of the

Ravikumar, Avinash, Wright, Stephen, Redmond, Laura, Gingrich, Eric, Korivi, Vamshi, Tess, Michael, Piehl, Joshua, Lawler, Benjamin

Elucidation of Deteriorating Oil Consumption Mechanism Due to Piston Top Ring Groove Wear

2024-01-2269

04/09/2024

The piston and piston ring are used in a severe contact environment in engine durability tests, which causes severe wear to the piston ring groove, leading to significant development costs for countermeasures. Conventionally, in order to ensure functional feasibility through wear on the piston top ring groove (hereinafter “ring groove”), only functional evaluations through actual engine durability testing were performed, and there was an issue in determining the limit value for the actual amount of wear itself. Because of this, the mechanism that may cause wear on the ring groove was clarified through past research, but this resulted in judgment criteria with some leeway from the perspective of functional assurance. To establish judgment criteria, it was necessary to understand both functional effect from ring groove wear and the mechanism behind it. For this research, the functional effect from wear on the upper surface of the ring groove and the mechanism that may cause this were

Yoshii, Kenta, Takahashi, Katsuyuki, Sato, Kenji, Hitosughi, Hideshi, Nakada, Fumihiro

Combustion Chamber Development for Flat Firedeck Heavy-Duty Natural Gas Engines

2024-01-2115

04/09/2024

The widely accepted best practice for spark-ignition combustion is the four-valve pent-roof chamber using a central sparkplug and incorporating tumble flow during the intake event. The bulk tumble flow readily breaks up during the compression stroke to fine-scale turbulent kinetic energy desired for rapid, robust combustion. The natural gas engines used in medium- and heavy-truck applications would benefit from a similar, high-tumble pent-roof combustion chamber. However, these engines are invariably derived from their higher-volume diesel counterparts, and the production volumes are insufficient to justify the amount of modification required to incorporate a pent-roof system. The objective of this multi-dimensional computational study was to develop a combustion chamber addressing the objectives of a pent-roof chamber while maintaining the flat firedeck and vertical valve orientation of the diesel engine. A new combustion chamber was designed based on a commercial 11-liter natural gas

Hoag, Kevin, Wray, Christopher, Callahan, Timothy J., Lu, Qilong, Gilbert, Ian, Abidin, Zainal

A Diesel Engine Ring Pack Performance Assessment

04-17-03-0013

03/23/2024

Demonstrating ring pack operation in an operating engine is very difficult, yet it is essential to optimize engine performance parameters such as blow-by, oil consumption, emissions, and wear. A significant amount of power is lost in friction between piston ring–cylinder liner interfaces if ring pack parameters are not optimized properly. Thus, along with these parameters, it is also necessary to reduce friction power loss in modern internal combustion engines as the oil film thickness formed between the piston ring and liner is vital for power loss reduction due to friction. Hence, it has also been a topic of research interest for decades. Piston and ring dynamics simulation software are used extensively for a better ring pack design. In this research work, a similar software for piston ring dynamics simulation reviews the ring pack performance of a four-cylinder diesel engine. Each piston ring performance is reviewed by studying gas pressure at lands, ting position in the groove, oil

Sanadhya, Kunjan, Malkhede, Dileep, Nandkumar, Milankumar Ramakant, Aghav, Yogesh, Kumar, M. N.

Internal Combustion Engines - Piston Ring-Grooves

J2275_202402 (Current)

02/16/2024

There is no ISO standard equivalent to this SAE Standard. This SAE Standard identifies and defines the most commonly used terms for piston ring-groove characteristics, specifies dimensioning for groove widths, and demonstrates the methodology for calculation of piston groove root diameter. The requirements of this document apply to pistons and rings of reciprocating internal combustion engines and compressors working under analogous conditions, up to and including 200 mm diameter and 4.5 mm width for compression rings and 8.0 mm width for oil rings. The specifications in this document assume that components are measured at an ambient temperature of 20 °C (68 °F). Tolerances specified in this document represent practical functional limits and do not imply process capabilities.

Piston and Ring Standards Committee

Power Cylinder Effects on Friction and Fuel Economy

J2904_202401 (Current)

01/22/2024

This document covers the mechanisms from the power cylinder, which contribute to the mechanical friction of an internal combustion engine. It will not discuss in detail the influence of other engine components or engine driven accessories on friction.

Piston and Ring Standards Committee

Effect of Piston Secondary Motion on Lubricating Oil Consumption, Blow-by and Friction

2024-26-0259

01/16/2024

As per pieces of literature, 40 to 60 % of friction losses of Internal combustion engines occur in their piston-piston rings-liner assemblies and, there is a significant supportive role of simulation in improving this assembly. Literature is also available which tells, how changes in pistons affect oil consumption. Thus, piston dynamics is also important for oil consumption. Furthermore, the results from the simulation module of piston movement also serve as a significant input for postprocessing to calculate piston ring dynamics. This research is conducted to understand the piston secondary motion effect on oil consumption, friction, and blow-by. In this work, the results of ring dynamics and oil consumption simulation modules are studied with consideration and non-consideration of piston secondary motion results. The results like minimum oil film thickness, lubricating oil consumption, friction, friction power loss, and blow-by are investigated. Results indicate that oil throw-off

Sanadhya, Kunjan, Nandgaonkar, M., Aghav, Yogesh

Cost Effective Pathways toward Highly Efficient and Ultra-Clean CI Engines, Part I: Combustion System Optimization

2024-26-0037

01/16/2024

Following global trends of increasingly stringent greenhouse gas (GHG) and criteria pollutant regulations, India will likely introduce within the next decade equivalent Bharat Stage (BS) regulations for Diesel engines requiring simultaneous reduction in CO2 emissions and up to 90% reduction in NOx emission from current BS-VI levels. Consequently, automakers are likely to face tremendous challenges in meeting such emission reduction requirements while maintaining performance and vehicle total cost of ownership (TCO), especially in the Indian market, which has experienced significant tightening of emission regulation during the past decade. Therefore, it is conceivable that cost effective approaches for improving existing diesel engines platforms for future regulations would be of high strategic importance for automakers. In this first of a two-part article, cost effective means of improving the combustion process in a Diesel engine to reduce engine-out emissions, specifically of NOx and

Shah, Ashish, Kumar, Praveen, Sari, Rafael, Cleary, David, Gothekar, Sanjeev, G Bhat, Prasanna, Thipse, Sukrut S

Experimental Study of Piston Temperature Profile with Respect to Varying Engine Parameters – Using Telemetry Method

2024-26-0341

01/16/2024

As emissions standards become more stringent, OEMs are pushing engines to run on leaner fuel mixtures, which puts increased thermal stress on components, particularly pistons, causing them to operate at higher temperatures. This requires more robust design and rigorous testing of components. Telemetry methods offer accurate and real-time feedback, allowing designers to test components at various operating conditions, providing more flexibility than other traditional methods. Piston temperature measurement is a critical aspect of engine development because it directly affects engine performance and durability. Among the various techniques available for this purpose, telemetry methods have gained considerable attention in recent years. This method involves integrating temperature sensors and transmitter on the piston, which transmit temperature data wirelessly to a receiver outside the engine. In this paper, we evaluate the impact of coolant temperatures, valve timing, ignition timing

Pandey, Ram Krishan, Kumar, Atul, Jangra, Sumit

Integrated Simulation Methodology to Predict Engine Head, Block, and Piston Temperatures

2024-26-0315

01/16/2024

With the constant strive towards increase in performance and corresponding stringent emission standards of modern IC engine, engine components such as the head, block and piston are subjected to higher thermal loads. An integrated simulation methodology is proposed where the head, the block and the piston are integral part of the analysis. The CFD – CHT methodology is used to simulate and predict the temperature of these engine components. The head and block are run in a steady-state conjugate heat transfer framework while the transient multiphase volume of fluid approach is used to determine piston temperatures. Combustion surfaces boundary conditions are derived from 3D CFD open-loop combustion simulation, while cooling and lubrication surface boundary condition are mapped from 1D system simulation or experimental data. The heat transfer boundary conditions are exchanged between the two simulations. The temperature field obtained from simulation is used further as input to perform

Sahu, Abhay Kumar, Chakkamadathil, Shirdi, Das, Debasis

Oil Aerosol Emission Optimization Using Deflectors in Turbo Charger Oil Drain Circuit

2024-26-0047

01/16/2024

Closed crankcase ventilation prevent harmful gases from entering atmosphere thereby reducing hydrocarbon emissions. Ventilation system usually carries blowby gases along with oil mist generated from Engine to Air intake system. Major sources of blowby occurs from leak in combustion chamber through piston rings, leakage from turbocharger shafts & leakage from valve guides. Oil mist carried by these blowby gases gets separated using separation media before passing to Air Intake. Fleece separation media has high separation efficiency with lower pressure loss for oil aerosol particles having size above 10 microns. However, efficiency of fleece media drops drastically if size of aerosol particles are below 10 microns. Aerosol mist of lower particle size (>10 microns) generally forms due to flash boiling on piston under crown area and from shafts of turbo charger due to high speeds combined with elevated temperatures. High power density diesel engine is taken for our study. It produces

M, Velshankar, Dharan R, Bharani, Dhadse, Ashish, Permude, Ashok, Loganathan, Sekar

Research on the Secondary Motion of Engine Piston Considering the Transport of Lubricating Oil

03-17-03-0024

11/21/2023

At present, it is generally considered in the analysis of the secondary motion of engine piston that the piston skirt–cylinder liner friction pair is fully lubricated in an engine operating cycle. However, in practice, when the piston moves upward, the amount of lubricating oil at the inlet may not ensure that the friction pair is fully lubricated. In this article, the secondary motion of piston is studied when the transport of lubricating oil is considered to determine the lubrication condition of piston skirt–cylinder liner friction pair. The secondary motion of piston is solved based on the combined piston motion model, hydrodynamic lubrication model, asperity contact model, and lubricating oil flow model. The secondary motion equation of piston is solved by the Broyden method. The hydrodynamic lubrication equation is solved by the finite difference method. The asperity contact between piston skirt and cylinder liner is calculated by the Greenwood model. The flow of lubricating oil

Liu, Jihai, Sun, Jun

Design Improvement of an Automotive Shock Absorber Component Subjected to Fretting Fatigue

2023-28-0157

11/10/2023

A shock absorber endurance test for an automobile that was supposed to resist at least 200,000 load cycles but failed to meet the statutory fatigue limit was under examination. This is due to the breakdown of the assembly that holds the shock absorber shims. This failure occurred due to Fretting fatigue. A design improvement is being introduced to avoid fretting fatigue on the shock absorber shim assembly. FEA is used to investigate the shim assembly in order to locate the stress zone. After adding more shims to the piston, fatigue life was significantly improved. The damping forces were unaffected by the fundamental solution that was applied to make this improvement.

Sharma, Ashish Gorishankar, Bhaskara Rao, Lokavarapu

Integrated Simulation Methodology to Predict Engine Head, Block, and Piston Temperatures

2023-01-1674

10/31/2023

With the constant strive towards increase in performance and corresponding stringent emission standards of modern IC engine, engine components such as the head, block and piston are subjected to higher thermal loads. An integrated simulation methodology is proposed where the head, the block and the piston are integral part of the analysis. The CFD – CHT methodology is used to simulate and predict the temperature of these engine components. The head and block are run in a steady-state conjugate heat transfer framework while the transient multiphase volume of fluid (VOF) approach is used to predict piston temperatures. Combustion surfaces boundary conditions are derived from 3D CFD open-loop combustion simulation, while cooling and lubrication surface boundary condition are mapped from 1D system simulation or experimental data. The heat transfer boundary conditions are exchanged between the two simulations. The temperature field obtained from simulation is used further as input to

Sahu, Abhay Kumar, CHAKKAMADATHIL, SHIRDI, Das, Debasis

Numerical Simulation of Turbulent Structures Inside Internal Combustion Engines Using Large Eddy Simulation Method

03-17-02-0011

10/16/2023

Using two subgrid-scale models of Smagorinsky and its dynamic version, large eddy simulation (LES) approach is applied to develop a 3D computer code simulating the in-cylinder flow during intake and compression strokes in an engine geometry consisting of a pancake-shaped piston with a fixed valve. The results are compared with corresponding experimental data and a standard K-Ɛ turbulence model. LES results generally show better agreement with available experimental data suggesting that LES with dynamic subgrid-scale model is more effective method for accurately predicting the in-cylinder flow field. Representative Fiat engine equipped with moving valve and piston bowl is analyzed as the second case to assess the capability of the method to handle complex geometries and impacts of geometrical parameters such as shape and position of piston bowl together with swirling intake flow pattern on both turbulent structure of in-cylinder flow and engine performance using dynamic version of LES

Aghamohamadi, Negin, Khaleghi, Hassan, Razaghi, Majid

Effect of Cross-Flow Velocity on Fuel Adhesion of Flat-Wall Impinging Spray under Triple Stage Split Injection

2023-32-0013

09/29/2023

The high injection pressure and small cylinder volume of direct injection spark ignition (DISI) engines can result in flat-wall wetness on the surface of the piston, increasing fuel consumption and pollutant emissions. The characteristics of microscopic fuel adhesion are observed using refractive index matching (RIM). Fuel adhesion characteristics after wall impingement are evaluated with various cross-flow velocities under triple stage injection conditions. The results indicate that cross-flow has a beneficial effect on the diffusion of fuel spray. Average fuel adhesion thickness decreases with an increase in cross-flow velocities. Furthermore, cross-flow promotes the evaporation of fuel adhesion, which leads to a reduction in the fuel adhesion mass/mass ratio. The improvement of injection strategy has guidance on low-carbon future.

SHI, Penghua, TRONG, Nguyen Binh, OGATA, Youichi, NISHIDA, Keiya, ZHANG, Gengxin, LUO, Hongliang

Clarification of Fuel and Oil Flow Behavior Around the Piston Rings of Internal Combustion Engines: Analysis and Observation of Lubricating Oil Dilution by Post Injection of Diesel Engine Using Oil Sampling and Photochromism Method

2023-32-0047

09/29/2023

The mechanism of lubricant dilution by post injection fuel in a diesel engine was investigated. The operating conditions of the engine were changed, and oil was sampled from each part of the piston and the crankcase, and the dilution ratio was analyzed. Also, photochromism was used to visualize the oil and fuel flow. Dilution ratios obtained from oil sampling and photochromism showed the same tendency.

Mihara, Yuji, Hirose, Yuya, Oikawa, Masakuni, Kyuu, Seikou, Nakakouji, Haruto, Sanda, Shuzo, Azetsu, Akihiko, Kawamoto, Yuki, Inoue, Naoki, Ito, Yuto, Ochiai, Masayuki, Takahashi, Shun

A Study on the Mechanism of Piston Ring Rotation of an Engine

2023-32-0033

09/29/2023

Engine oil consumption must be reduced because it produces particulate matter in exhaust gases and poisons the catalyst in an aftertreatment system. Oil transport upward via piston ring gaps is one of the factors for oil consumption. It is known that piston rings rotate circumferentially during engine operation, and that oil consumption increases when the ring gaps of multiple piston rings are close to each other. Force acting on a piston ring in the circumferential direction was investigated in a past study [3], and a wave form of the force was measured against the crank angle. Furthermore, the forces were varied according to the measurement position in the circumferential direction. It means that the ring gap tends to stay where the force showed a small value. The force shows a periodic wave form against the crank angle for each cycle, and some parts of the waveform show a correlation with piston slap motion [3]. Piston motion consists of lateral motion, tilting motion and up-and

Kanemoto, Kaito, Ito, Akemi

Analytical Study on Involvement of Temperature in Friction and Scuffing for Engine Tribo-Components

2023-32-0115

09/29/2023

Regarding the solution for various issues on engine tribology, in order to understand the involvement of temperature in the friction and scuffing under the mixed and/or boundary lubrication regime, the two cases of piston ring & cylinder liner and cam & tappet were analytically studied. The friction between sliding interfaces is composed of four shear stresses from the viscous oil-films, the adsorbed oil molecules, the tribofilms due to oil additives, and the true metal contacts on surface asperities. Since all the shear stress have exponential temperature dependences, the relationship between the frictional shear stress and temperature is assumed to be expressed by the Arrhenius equation. Through analyzing friction data measured in laboratory tests conducted under the same temperature and sliding conditions as during the break-in of engines, various levels of temperature involvement were clarified.

Soejima, Mitsuhiro, Hamatake, Toshiro, Kitahara, Tatsumi, Smith, Edward H., Sherrington, Ian

Operating Characteristics of a Spark-Ignition Engine Using Hydrogen and Ammonia

2023-32-0105

09/29/2023

In this research, the operating characteristics of a spark-ignition engine using ammonia were evaluated. Different compression ratios and two pistons with different squish velocities were used. Results show that the combustion duration was shortened with high compression ratio and high squish piston, and the stable operation range of the engine was expanded. BMEP and brake thermal efficiency did not change significantly among the stable operation range for variations of compression ratio, squish velocity. Due to the reduction effect of unburned ammonia, NOx emissions decreased when ammonia mole fraction increased. Most of the unburned ammonia was emitted from the quenching layer.

Ichikawa, Aya, Sekine, Masamichi, Hara, Takumi, González Palencia, Juan C., Araki, Mikiya, Shiga, Seiichi, Kambara, Shinji

Items per page:

1 – 50 of 3784