Reduced raw emissions from internal combustion engines (ICE) are a key requirement to reach future green-house-gas and pollutive emissions regulations. In parallel, to satisfy the need for increased engine efficiencies, the friction losses of ICEs gains attention. Measures to reduce parasitic drag inside the piston assembly such as reduced piston-ring pretension or thinner grade engine oils may increase oil ingress into the combustion chamber. The oil ingress is known to imply increased particle emissions directly counteracting the raw emission reduction target of engine development. To resolve this target conflict, the transport mechanisms of oil into the combustion chamber are the topic of current research. Specially developed research engines featuring a vertical optical window come with big potential to visualize the phenomena of the oil behavior inside the piston assembly group. Such ‘glass-liner’ engines play a pivotal role in identification and quantification of local and global

Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte

Grease, Aircraft, General Purpose, Low Temperature Range, Lithium Thickened

AMS3052B (Current)

06/30/2025

This specification covers grease for use within an aircraft. It also defines the quality control requirements to assure batch conformance and materials traceability and the procedures to manage and communicate changes in the grease formulation and brand. This specification invokes the Performance Review Institute (PRI) product qualification process. Requests for submittal information may be made to the PRI at the address in 2.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Additional tests and evaluations may be required by individual equipment builders before a grease is approved for use in their equipment. Approval and/or certification for use of a specific grease in aero and aero-derived marine and industrial applications is the responsibility of the individual equipment builder and/or governmental authorities and is not implied by compliance with or qualification to this specification.

AMS M Aerospace Greases Committee

Heavy-Duty Vehicle Lubricating Greases

J2695_202506 (Current)

06/30/2025

This SAE Recommended Practice was developed by SAE and the section “Standard Classification and Specification for Service Greases” cooperatively with ASTM and NLGI. It is intended to assist those concerned with the design of heavy-duty vehicle components and with the selection and marketing of greases for the lubrication of certain components on heavy-duty vehicles like trucks and buses. The information contained herein will be helpful in understanding the terms related to properties, designations, and service applications of heavy-duty vehicle greases.

Fuels and Lubricants TC 3 Driveline and Chassis Lubrication

Aviation Lubricant Tribology Evaluator (ALTE) Method to Determine the Lubricating Capability of Gas Turbine Lubricants

ARP6255A (Current)

05/16/2025

Employing “ball-on-ring” philosophy, a nonrotating steel ball is held in a vertically mounted chuck and, using an applied load, is forced against an axially mounted steel rotating ring. The test ring is rotated at a fixed speed while being partially immersed in a lubricant reservoir. This maintains the ring in a wet condition and continuously transports a lubricating film of test fluid to the ball and ring interface. The diameter of the wear scar generated on the test ball is used as a measure of the fluid’s lubricating properties. The apparatus can be used by adjusting the operating conditions to reproduce two different wear mechanisms. Therefore, the ALTE can assess a lubricant’s performance in that regard. These mechanisms are described below.

E-34 Propulsion Lubricants Committee

Prediction of Pre-Ignition Borderline on Supercharged SI Engine by Livengood-Wu Integral

2024-32-0008

04/18/2025

The LSPI (Low Speed Pre-Ignition) is one of the consecutive abnormal combustion cycles of supercharged SI engine with direct injection fuel supply system [1]. The LSPI occurs when the engine is running at low speed and high load condition. It is important for the SI engine to control essentially with alternative fuel, e-fuel and hydrogen in the future. It is considered that the LSPI would be caused by the autoignition of the deposit, the lubricating oil from ring crevice, the lubricating oil from piston crown and so on [2, 3, 4, 5]. Among of these causes, this research focuses on the scattering lubricating oil from piston crown. The previous our research has reported on the two points. One is about the frequency and quantity of the lubricating oil scattering from piston crown [6]. Another is about the frequency of abnormal combustion by the engine test [7]. As the result, it has been cleared that the frequency of abnormal combustion is 1/10 of scattering frequency of the lubricating

Omori, Takaya, Tanaka, Junya

Used Motor Oil Regeneration Efficiency of Type X Fly Ash–Based Zeolite Alone and Combined with Other Adsorbents

04-18-03-0013

04/15/2025

This research article assesses the used motor oil’s (UMO) regeneration efficiency of a synthetic type X zeolite (siliceous fly ash–based) alone and combined with other adsorbents (composite adsorbents), namely activated carbon, bentonite, and acid-activated bentonite from Goshica’s (Kosovo) region. The UMO treated with the regenerating mixes has run about 20,000 km. Parameters including density, kinematic viscosity, viscosity index, pour point, and sulfur content were measured in the untreated and treated UMO and compared to those of the reference oil with additives of type SAE 5W-30. All regeneration mixes showed good regeneration efficiency, restoring the UMO’s parameters to almost the original ones of the reference oil with additives (SAE 5W-30). Only the zeolite alone could significantly reduce the sulfur content (removal efficiency 60%). This method deserves further investigation and with some improvements, it can be established as a reliable regeneration method for some UMO.

Korpa, Arjan, Dervishi, Sara, Gecaj, Diana, Shahu, Kristi, Shehu, Alma, Nuro, Aurel

Effects of Lubricating Oil Consumption and Operation Duration on CO ₂ Accumulation and Efficiency in an Argon Power Cycle Hydrogen-Fueled Engine

2025-01-8436

04/01/2025

The trend of internal combustion engines is reducing or eliminating carbon emissions and improve the overall efficiency. The Argon Power Cycle hydrogen-fueled engine can specifically improve the thermal efficiency by employing argon as the working substance. At the same time, due to the utilization of hydrogen and oxygen, the combustion of the fuel in Argon Power Cycle hydrogen-fueled engines produces zero carbon emissions or NOx emissions. However, during engine operation, lubricating oil consumption can still generate CO2 and becomes the only source for carbon emissions. Furthermore, the accumulation of CO2 under closed cycle will impede the condensation recovery of argon and reduce the efficiency and power. In this study, a closed cycle model of Argon Power Cycle hydrogen-fueled engine was constructed, in which argon is recycled by condensation instead of being charged like air in an open cycle model. Effects of lubricating oil consumption and operation duration on CO2 accumulation

Wang, Chenxu, Li, Mo, SU, Xiang, Deng, Jun, Tian, Tian, Li, Liguang

Engine Crankcase, Oil Pan and Lube System Multiphase CFD Analysis for Predicting Oil Aeration

2025-01-8364

04/01/2025

This paper explains transient, computationally rigorous, three-dimensional and one-dimensional multiphase CFD analysis of engine oil drainback system and lubrication system for predicting aeration. Aeration of engine oil is an important factor as it affects working of Hydraulic Lash Adjusters, bearings performance and it reduces lube system pressure itself which is detrimental for the entire engine. In this work specifically effect of engine tilting on lube oil aeration is presented. When engine is tilted, crankshaft and connecting rod/s are dipped in to oil, which creates air bubbles. These air bubbles travel to lube pump and then to the engine lube system. Therefore, it is essential to model aeration in Engine crankcase, Oil pan and Lube system for the purpose of predicting oil pressure reduction in lube system. The problem under consideration is spread over a bigger zone, involves rotating and translating components, passage’s dimensions are varying from microns to meters and

Tawar, Ranjit Ramchandra, Bedekar, Sanjeev

Reduced Order Model for Viscosity and Mass Density Sensing by A U-Shaped Wire

2025-01-8472

04/01/2025

This paper focuses on the basic principle of measuring viscosity and density with U-shaped tungsten wire sensor, and develops a model for measuring liquid viscosity and density with the help of oscillating ball model. Firstly, the working mechanism of the wire resonator is deeply analyzed. Then, by reducing the order of the fluid dynamic function, a simplified model is established for measuring the viscosity and density of liquid with U-shaped tungsten resonator. The experimental results show that the maximum error of viscosity is 7.22% and the average error is 2.81% when the viscosity ranges from 4.526mPa.s to 62.01mPa.s. In the range of 0.8486g/cm3 to 0.8711g/cm3, the maximum density error is 7.00% and the average density error is 1.89%. In summary, the simplified model proposed in this paper can accurately measure the viscosity and density of liquids.

Shan, Baoquan, Shen, Yitao, Yang, Jianguo, Zhang, Zhaoying, Wu, Dehong, Zhao, Yingke

Intebrake 3-D CFD Transient Simulation Studies for Predicting Flow Performance

2025-01-8362

04/01/2025

This paper presents transient, complex, moving mesh, 3-D CFD analysis of an intebrake lubrication oil circuit for predicting flow performance. Intebrake is a mechanism for improving braking performance during over speeding conditions. The mechanism briefly opens the exhaust valve at the end of a compression stroke with a small valve lift and releases the compressed gases, thereby helping in quick application of the brake. There is no fueling during the process and hence, no combustion induced pressure rise which helps in quick application of the brake. During the intebrake operation, opening of the exhaust valve is achieved by using a complex lube oil circuit inside the exhaust rocker lever. The intebrake lube oil circuit consists of various spring-operated valves with micro-sized clearances, high oil pressure generation up to ~ 250 bar, 3-D movement of the mechanism components, and it is a transient operation. The 3-D movement consists of simultaneous rotational and translational

Tawar, Ranjit Ramchandra, Pasunurthi, Shyam Sundar, Bedekar, Sanjeev, Ranganathan, Raj

Machine Learning-Based Digital Twin for Optimizing Automotive Components

2025-01-8206

04/01/2025

This paper presents a Digital Twin approach based on Machine Learning (ML), aimed at creating software-based sensors to reduce the auxiliary devices of the vehicle and enabling predictive maintenance, thus reducing carbon footprint. The solution is applied to the electric Lubrication Oil Pump (eLOP), a crucial component within a vehicle's powertrain system. The proposed eLOP Digital Twin integrates ML-based sensors to estimate critical parameters such as temperature, pressure and flow rate, reducing the reliance on physical sensors and associated hardware. This approach minimizes manufacturing complexity and cost, enhancing energy efficiency during both production and operation. Furthermore, the Digital Twin facilitates predictive maintenance by continuously monitoring the component's performance, enabling early detection of potential failures and optimizing maintenance schedules. This leads to lower energy consumption and reduced emissions throughout the component's lifecycle. The

Khan, Jalal, D'Alessandro, Stefano, Tramaglia, Federico, Fauda, Alessandro

Development of Dehydrated Kusum Oil as a Potential Bio-Lubricant

2025-01-8312

04/01/2025

Depletion of petroleum crude oil and its environmental impacts challenge future generations. Vegetable oils provide a sustainable alternative with benefits like anti-wear properties, biodegradability, and renewability. Kusum oil's ability to lower carbon emissions significantly and promote sustainable industrial practices highlights its potential as a viable green alternative. This research paper presents a comprehensive and comparative analysis of a sustainable, environmentally friendly bio-lubricant and nonedible vegetable oil like Kusum oil. Bio-lubricant is produced by transesterification followed by epoxidation, which is known as epoxidized kusum oil lubricant or dehydrated kusum oil (DKO). The process of epoxidation significantly enhances the properties of Kusum oil, making it a promising alternative to conventional lubricants. It is compared with a widely used conventional mineral oil lubricant like SAE10W40. DKO exhibits comparable density, viscosity index, pour point, and

Prabhakaran, J, Pali, Harveer Singh, Singh, Nishant K.

A Comparative Study on the Working Efficiency of Journal Bearing Employing Different Micro-Textures

04-18-02-0011

02/19/2025

This study proposed the different micro-textures of the SC (square cylinder), SWS (square wedge shape), HS (hemispherical shape), and CR (cylindrical round) to improve the working efficiency of the journal bearing. A hydrodynamic lubrication model of the journal bearing under the impact of the changing dynamic loads is established to analyze the performance of micro-textures. The maximum oil film pressure and minimum frictional force in the journal bearing are selected as two evaluation indices. Some outstanding research results show that all the SC, SWS, HS, and CR added on the bearing surface improved the working efficiency of the journal bearing better than without the micro-textures. Moreover, the HS also improved the working efficiency of the journal bearing better than other structures of SC, SWS, and CR. To optimize the working efficiency of the journal bearing using HS, the dimension ltex and depth htex of HS should be selected and designed in a range of 3.6 < ltex ≤ 3.9 mm and

Song, Fengxiang, Nguyen, Vanliem, Liu, Yaxi

A Critical Evaluation of Laboratory Test Methods Used to Assess Coke Formation Tendency in Synthetic Lubricants

2025-28-0036

02/07/2025

Lubricant oil in combustion engines undergoes thermal degradation under high temperatures and forms solid deposits. These deposits, called coke, are insidious, black, and carbonaceous solids. To mitigate the problems associated with oil coking, an effective testing methodology must be developed to characterize the coke formation qualitatively and quantitatively. Previously, testing methodologies have been developed to measure coking tendency however some of the international standards such as the SAE ARP 6166 use visual inspection methods to assess coke. Such methods are unsuitable for advanced research as they are prone to error in human judgment. This paper intends to bridge this gap and discusses test methodologies that can measure Coke quantitatively and qualitatively. Coke formation has been studied using different laboratory methods such as static immersion, thin film oxidation, and dynamic spray tests to replicate the various conditions. In a static immersion test, a metal

Jeyaseelan, Thangaraja, S, Shanmugasundaram, Bansal, Lalit, Negi, Ashish, Koka, Tirumala Rao, Das, Arnab

Improving the Carbon Footprint of Long-Haul Trucks Running on First-Generation Biodiesel

2025-01-5007

01/27/2025

Lowering carbon emissions from road-based transport is required to achieve climate targets. In addition to passenger cars, long-haul trucks contribute more than one-third of on-road generated carbon emissions. Therefore, this sector has great potential to reduce such emissions. Numerous options including electrified drivetrains are possible. Nevertheless, the existing fleet of trucks powered by conventional diesel engines also needs to be addressed. Additionally, a ramp-up of green electricity and charging infrastructure is required to ensure carbon-neutral and reliable transport. Heavy-duty diesel engines are typically suitable for use with first-generation biofuels. However, operational restrictions, such as shorter oil drain intervals are mandatory for users. In the case at hand, the oil change was mandatory after only 30,000 km when pure biodiesel (B100) was used instead of 120,000 km when operating on conventional, mineral oil-based diesel. These boundaries counter efforts to

Rohbogner, Christoph J., Heine, Carsten

Analysis of the Characteristics of Hybrid Vehicles and Low-Viscosity Lubricating Oil Based on Real Road Tests in Four Extreme Environments

04-18-02-0009

01/07/2025

As countries around the world attach more importance to carbon emissions and more stringent requirements are put forward for vehicle emissions, hybrid vehicles, which can significantly reduce emissions compared with traditional fuel vehicles, as well as low-viscosity lubricating oil, have become significant trends in the industry. In this article, a total of nine vehicles of 48 V mild-hybrid models and full-hybrid models are tested. Using three kinds of low-viscosity lubricating oil and driving a total of 120,000 km in environments with low temperature, high humidity, high temperature, or high altitude, the engines are then disassembled and scored. The effects of the four extreme environments on the engine starts–stops, ignition advance angle, engine power, state of charge (SOC), acceleration performance, and oil consumption characteristics of hybrid vehicles are studied; the oxidation characteristics and iron content change characteristics of low-viscosity lubricating oil are analyzed

Zhu, Gezhengting, Hu, Hua, Pan, Jinchong, Luo, Yitao, Hua, Lun, Jiao, Yan, Jiang, Jiandi, Shao, Heng, Xu, Zhengxin, Yan, Jingfeng, Wei, Guangyuan, Zhang, Heng

A Quasi-Two-Dimensional Approach in Laminar Flow of Lubricating Oil and Grease

04-18-02-0007

12/09/2024

The overarching objective of the present study is to apply a quasi-two-dimensional approach to analyze the laminar flow of lubricating oil. Lubricating oils are non-Newtonian by nature. For these types of oils, the Sisko fluid model is the most suitable model of the nonlinear stress–strain relationship for these types of oils. It is hoped that by omitting the dependence of flow quantities in one direction, more qualitative information can be obtained on the characteristics of the purely three-dimensional boundary layer flow of lubricating oils. Some of the most familiar flow geometries discussed are steady flow over a flat plate, a corner of a wedge, and a stagnation region; steady flow in a convergent and divergent channel; and impulsively started flow over an infinite flat plate and semi-infinite flat plate. The governing equations of all flow geometries are transformed into nonlinear ordinary differential equations (ODE) using the free parameter transformation. The results are

Patel, Manisha, Bariya, H.G.

Development of Lubricants Using Re-Refined Base Stocks—An Effort toward Circular Economy

04-18-02-0008

12/06/2024

Re-refining of used lubricating oil is an economically attractive and effective recycling method that contributes significantly to resource conservation and environmental protection. The effective re-refining process of used lubricating oil undergoes thorough purification to remove contaminants and to produce high yield and good quality base oil suitable for reuse in lubricant formulation. Used lubricating oils have various hazardous materials, these can be processed with safe and efficient methods required to recover high-quality base oil products. Typically, used lubricating oil is a mixture of various types of additives, base oils, and viscometric grades as per the different types automotive and industrial applications. Re-refined base oils can be re-used to produce lubricants such as industrial and automotive lubricants like passenger car motor oils, transmission fluids, hydraulic oils, and gear oils. API classified base oils into two categories namely mineral base oils API Group I

Maloth, Swamy, Joshi, Ratnadeep S., Mishra, Gopal Swaroop, Samant, Nagesh N., Bhadhavath, Sanker, Seth, Sarita, Bhardwaj, Anil, Paul, Subinoy, Arora, Ajay Kumar, Maheshwari, Mukul

Towards Robust Hydrogen Combustion: Precise Lube Oil Consumption Measurement as an Enabler for Tackling Pre-Ignition

2024-01-4290

11/05/2024

The use of carbon-free fuels, such as ammonia or hydrogen, or at least carbon neutral fuels, such as green methane or methanol is one of the most important paths in the development of low-carbon internal combustion engines (ICE). Especially for large, heavy-duty engines, this is a promising route, as replacing them with battery electric or fuel cell drives poses even greater challenges, at least for the time being. For some applications or areas of the world, small ICEs for trucks, passenger cars or off-road vehicles, operated with alternative fuels will still remain the means of choice. One of the biggest challenges in the development of hydrogen combustion engines is achieving high compression ratios and mean effective pressures due to combustion anomalies, caused by the low ignition delay and broad flammability limit of hydrogen. Oil droplets are considered to be one of the main triggers for pre-ignition and knocking. This paper will give a brief introduction, showing the results of

Rossegger, Bernhard, Grabner, Peter, Gschiel, Kevin, Vareka, Martin

The Effect on Soot Handling and Friction of Selected Dispersant Additives for Next Generation Transportation Sector Oils

2024-01-4301

11/05/2024

Next generation lubricating oils for transportation sector require higher durability in operation, compatibility with new engine technologies and aftertreatment devices as well as high fuel economy (FE), thus contributing to the reduction of CO2 emissions, both in passenger cars and heavy-duty vehicles. The current paper aims to highlight the impact of dispersant main properties in preventing sludge and deposits formation on engine surfaces. The effect on frictional properties of lubricating oils through a multi-step activity was evaluated. Oil contamination by soot is a big concern not only for diesel but also for new generation of direct injection gasoline (GDI) engines. The presence of soot leads to oil thickening that heavily impacts on friction coefficient thus enhancing the role of dispersant in controlling soot and related viscosity increase and, indirectly, fuel consumption for long running periods. After an introduction on dispersant technologies, the focus of the paper moves

Lattuada, Marco, Manni, Massimo, Notari, Marcello, Ferraro, Giovanni, Fratini, Emiliano

Lubricating Oil, Aircraft Piston Engine (Ashless Dispersant)

J1899_202410 (Current)

10/28/2024

This SAE Standard establishes the requirements for lubricating oils containing ashless dispersant additives to be used in four-stroke cycle, reciprocating piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-22851. Users should consult their airframe or engine manufacturer’s manuals for the latest listing of acceptable lubricants. Compliance with this specification must be accomplished in accordance with the Performance Review Institute (PRI) product qualification process as described in the documents referenced in 2.1.3. Requests for submittal information may be made to the PRI at the address shown in 2.1.3, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Approval and/or certification for use of a specific piston engine oil in aero applications is the responsibility of the individual equipment builders and/or governmental

E-38 Aviation Piston Engine Fuels and Lubricants

Influence of Lube Oil and Fuel Additives on the Particulate Raw Emission Behavior of Gasoline Engines

04-18-01-0004

10/03/2024

The aim of this work was to investigate the influence of different combinations of engine oil and oil additive as well as additivated and unadditivated fuel on particulate emissions in gasoline engines. To accomplish this, load, speed, and type of oil injection were varied on a single-cylinder engine, and the influence on particle number concentration and size distribution were evaluated. The tests were supplemented by an optical investigation of their in-cylinder soot formation. The investigation of fuel additives showed no significant differences compared to the reference fuel without additives. However, in the case of oil additives, detergents led to a significant increase in the number of particles in the <20 nm range. This effect occurred when used as both a single additive and a component in the standard engine oil. While viscosity improvers also lead to a measurable, but less pronounced, increase in the particle number concentration, no significant influence can be determined

Böhmeke, Christian, Heinz, Lukas, Wagner, Uwe, Koch, Thomas

Influences of Lubricant Viscosity and Metallic Content on Diesel Soot Oxidation Reactivity

2024-01-5084

08/23/2024

This study examined the effects of lubricant viscosity and metallic content on the oxidation reactivity of diesel particles. In the first part, the factors affecting thermogravimetric analysis (TGA) experiments was discussed and confirmed. The influences of initial soot mass, heating rate, and airflow rate on soot oxidation rate and experimental reproducibility were investigated to develop an optimized TGA method. On the basis of these experiments, an initial soot mass of 2.0 mg, airflow rate of 4.8 L/h, and heating rate of 2.5°C/h were used for all subsequent TGA tests. It could be found that the TGA experiments had high repeatability, and the differences were less than 0.1%. In the second part, a four-cylinder diesel engine was lubricated with seven kinds of lubricant with different viscosity and metallic content by the use of viscosity index improver (VII), antioxidant and corrosion inhibitor (ACI), and ashless dispersant (AD). Particle samples were subjected to TGA to test their

Meng, Hao, Yang, He, Zhang, Weili, Xing, Jianqiang, Xu, Yan, Wang, Yajun

Lubricating Oils, Aircraft Piston Engine (Non-Dispersant)

J1966_202408 (Current)

08/19/2024

This SAE Standard establishes the requirements for non-dispersant lubricating oils to be used in four-stroke cycle piston aircraft engines. This document covers the same lubricating oil requirements as the former military specification MIL-L-6082. Users should consult their airframe or engine manufacturers’ manuals for the latest listing of acceptable lubricants. Compliance with this specification must be accomplished in accordance with the Performance Review Institute (PRI) product qualification process as described in the documents referenced in 2.2.2. Requests for submittal information may be made to the PRI at the address shown in 2.2.2, referencing this specification. Products qualified to this specification are listed on a Qualified Products List (QPL) managed by the PRI. Approval and/or certification for use of a specific piston engine oil in aerospace applications is the responsibility of the individual equipment builders and/or governmental authorities and may be accomplished

E-38 Aviation Piston Engine Fuels and Lubricants

Challenges of Measuring Low Levels of CO ₂ and NO _x on H ₂ -ICE

2024-01-2998

07/02/2024

Society is moving towards climate neutrality where hydrogen fuelled combustion engines (H2 ICE) could be considered a main technology. These engines run on hydrogen (H2) so carbon-based emission are only present at a very low level from the lube oil. The most important pollutants NO and NO2 are caused by the exhaust aftertreatment system as well as CO2 coming from the ambient air. For standard measurement technologies these low levels of CO2 are hard to detect due to the high-water content. Normal levels of CO2 are between 400-500 ppm which is very close or even below the detection limit of commonly used non-dispersive-infrared-detectors (NDIR). As well the high-water content is very challenging for NOx measuring devices, like chemiluminescence detectors (CLD), where it results in higher noise and therefore a worse detection limit. Even for Fourier-transformed-infrared-spectroscopy-analysers (FT-IR) it is challenging to deal with water content over 15% without increased noise. The goal

Jakubec, Philipp, Roiser, Sebastian

Optimization of a Sliding Rotary Vane Pump for Heavy Duty Internal Combustion Engine Cooling

2024-37-0030

06/12/2024

The benefits introduced by the replacement of conventional centrifugal pumps with volumetric machines for Internal Combustion Engines (ICEs) cooling were experimentally and theoretically proven in literature. Sliding Rotary Vane Pumps (SVRPs) ensure to achieve an interesting reduction of ICEs fuel consumption and CO2 emissions. Despite volumetric pumps are a reference technology for ICE lubrication oil circuits, the application in ICE cooling systems still not represent a ready-to-market solution. Particularly challenging is the case of Heavy-Duty ICEs due to the wide operating range the pump covers in terms of flow rate delivered and pressure rise. Generally, SVRPs are designed to operate at high speeds to reduce machine dimensions and, consequently, the weight. Nevertheless, speed increase could lead to a severe penalization of pump performance since the growth of the friction losses. They produce wear phenomena which require expensive surface treatments or, more generally, the

Fatigati, Fabio, Di Bartolomeo, Marco, Pallante, Francesco, Lo Biundo lng, Giuseppe, Cipollone, Roberto

The Effects of the Oil Temperature Warm-Up on Engine Fuel Consumption

2024-01-2411

04/09/2024

The need for even more efficient internal combustion engines in the road transportation sector is a mandatory step to reduce the related CO2 emissions. In fact, this sector impacts significantly on greenhouse gases worldwide, and the path toward hybrid and electric powertrains has just begun. In particular, in heavy-duty vehicles the full electrification of the powertrain is far to be considered as a really feasible alternative. So, internal combustion engines will still play a significant role in the near/medium future. Hence, technologies having a low cost to benefits (CO2 reduction) ratio will be favorably introduced in existing engines. Thermal management of engines is today a recognized area of research. Inside this area, the interest toward the lubricant oil has a great potential but not yet fully exploited. Engine oil is responsible of the mechanical efficiency of the engine which has a significant potential of improvement. A faster warm-up during a daily urban trip when the

Di Giovine, Giammarco, Di Battista, Davide, Cipollone, Roberto

A 3-D CFD Study of the Lubricating Oil Flow Path in a Hybrid Vehicle Transmission System

2024-01-2635

04/09/2024

Effective design of the lubrication path greatly influences the durability of any transmission system. However, it is experimentally impossible to estimate the internal distribution of the automotive transmission fluid (ATF) to different parts of the transmission system due to its structural complexities. Hybrid vehicle transmission systems usually consist of different types of bearings (ball bearings, thrust bearings, roller bearings, etc.) in conjunction with gear systems. It is a perennial challenge to computationally simulate such complicated rotating systems. Hence, one-dimensional models have been the state of the art for designing these intricate transmission systems. Though quantifiable, the 1D models still rely heavily on some testing data. Furthermore, HEVs (hybrid electric vehicles) desire a more efficient lubrication system compared to their counterparts (Internal combustion engine vehicles) to extend the range of operation on a single charge. Thus, this paper includes a

Mohapatra, Chinmoy K., Schlautman, Jeff, Liu, Zhe, Raj, Gowtham, Gao, Haiyang

A methodology for modeling the thermal behavior of an electric axle in real driving cycles

2024-01-2588

04/09/2024

The thermal behavior of the electric axle is an essential indicator which requires certain attention during the development process. Due to the complexity of heat generation mechanism and heat transfer boundary conditions, it is difficult to accurately predict the axle’s temperature, especially in real driving conditions. In this paper, a comprehensive 1D model is developed to simulate its heat transfer process effectively and accurately. The heat transfer model is developed based on the thermal network method, and the electric axle is divided into thermal mass according to its heat transfer characteristics. The heat generation model, which accounts for meshing loss, bearing loss, churning loss, and windage loss, exchanges heat flux and oil temperature information with the heat transfer model to take into account the effect of lubricating oil temperature on power loss. Meanwhile, 3D simulation is established for the lubricating oil flow inside the axle and the air flow around it, from

Hu, Xiaoyu, Shao, Hengheng, Hou, Yuanjing, Sun, Wanyu, Liu, Hongwei, Zhang, Lin

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

Simulation Study on the Influence of Multi-Magnetic Particles on Oil Sensor Signals

2024-01-2826

04/09/2024

Engine operation produces particles that contaminate the lubricating oil and can damage the engine's internal components. This paper presents a model for a three-coil inductive metal particle sensor and verifies the rationality and accuracy of the model by simulating the motion of a single spherical iron particle passing through the sensor. On this basis, the simulation of coupling double particles with different sizes, distances, and shapes is carried out. The study explores the influence of particle motion on the sensor-induced signal under various conditions. The research shows that when two particles pass through the sensor, the induced voltage signal will produce superposition when the distance between the two particles is small. The peak value of the induced voltage is 1-2 times the peak value of the induced voltage of a single particle. As the distance increases, the peak value of the induced voltage initially decreases, then slowly increases, and finally stabilizes. When the

Chen, Sen, Shen, Yitao, Qiang, Guiyan, Zheng, Zheng, Wang, Zheyu, Hao, Yin, Hu, Ting

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

A Study of Engine Oil Aeration in IC Engines and Factors Contributing It

2024-26-0370

01/16/2024

The lubrication system of an internal combustion engine is a crucial component that performs a variety of functions, including lowering friction, cooling, supporting the load, and cleaning debris from the engine’s various moving components. Oil aeration refers to the phenomenon of trapping air bubbles in lubricating oil. High oil aeration can have a detrimental effect on engine performance since modern engines are equipped with parts such as VVT, HLA, RFF, PCJ, LCJ, and other components; whose operation is substantially impacted by the amount of air in circulating oil. In this study, an Inline 4-cylinder NA DOHC gasoline engine was tested with a densimeter-type aeration measuring machine. Test equipment layout which consists of hoses of various diameters and lengths were designed, fabricated, and instrumented to operate under different test conditions. Visual observations and quantitative measurements of oil aeration were performed in the oil sump. The purpose of this study is to

Attri, Mayank, Yadav, Vimal, Kamboj, Jagdish

Conversion of Diesel Fuel System to CNG Fuel System for Commercial Vehicles

2024-26-0382

01/16/2024

CNG fuel has recently gained popularity in passenger and commercial vehicles due to its lower cost of operation compared to gasoline and diesel. It is also a more environmentally friendly fuel than other fuels. Converting a customer vehicle with a Diesel option to a CNG option is more difficult than building a new CNG vehicle. In this we are outlining the design of CNG fuel systems and the challenges of replacing them during the transition from Diesel to CNG and qualifying the Government Norms for running the vehicle will increase the life as well as make our environment more eco-friendly than diesel vehicles. Using CNG as a fuel in the automotive industry gives benefits over Gasoline & Diesel • increased life of lubricating oils, as CNG does not contaminate and dilute the crankcase oil. • Lower cost of per unit energy. • Being a gaseous fuel, CNG mixes easily and evenly in air, hence less hazardous. • CNG is less likely to touch off on hot surfaces since it includes a tall auto

Srivastava, Rajat, Sharma, Mukesh, Kumar, Satish, Sharma, Pawan, Singh, Gaurav

Optimization of Oil Quantity in Manual Transmission and Reducing Churning Loss

2024-26-0346

01/16/2024

The gearbox is a crucial aggregate in a diesel truck. Gearboxes must work efficiently to get the job done properly and lubrication is vital to this efficiency. Lubricating oil is like the circulation system of a gearbox. If the oil levels fall too low, the gearbox will likely fail. Gearbox failure can lead to expensive repairs that could be prevented. Besides added costs due to replacement or repair, costs associated with a loss of production could be significant. These issues are why; it is important to understand the consequences of having low lubricant levels. Similarly, higher oil level creates higher churning losses, heating of the Gear oil and oxidation, reduction in efficiency and increased oil leaks. Understanding the functions of gearbox lubricating oil can help you choose the right quantity of prevent gearbox failures. The aim of the testing is to find the accurate level of oil required to lubricate the Gearbox properly without failure and to reduce from the current predicted

Lakshamanan, Sundar, Ks, Dhianeshwar, G R, Santosh, Ramaswamy, Sarathkumar

Lubrication Evaluation of EV Transmission

2024-26-0328

01/16/2024

Advent of EV powertrain has considerable effect on transmission development activities as competed to regular ICE transmission. Conventional ICE transmission and the transmission for an e-powertrain differ on fundamental level. The conventional transmission has number of gear ratios, shift mechanism which enables the transmission to deliver a smooth power output as per demand from the driver. Whereas the e-powertrain transmission is mostly a single gear ratio transmission (reducer) which primarily depends on speed and torque variation from the motor to cater the driver requirement. Hence, the operating speeds of such e-transmissions can vary from 0 to 20000 rpm in both forward and reverse directions. Such a large speed variation as compared with conventional transmission calls for special attention towards the lubrication of internal components. High speeds and lower oil viscosities tend to disrupt the oil films in between contact surfaces causing metal to metal contact. This situation

Kushwaha, Rakesh, Bhosale, Vikas, Navale, Pradeep, Patel, Hiral

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

Improving the Gearbox Efficiency by Reducing Drag Loss IN Automotive Manual Transmission

2023-28-0115

11/10/2023

Internal combustion engine vehicles are major contributors to many environmental and health hazardous emissions and sometimes consume more fuel. New regulations like Corporate Average Fuel Efficiency (CAFÉ) norms are coming up and demand lower emissions. Original Equipment Manufacturers (OEMs) are committed to bringing various technological advancements in Internal Combustion Engine (ICE)powered vehicles to maximize their efficiency. Hence it is important to reduce the loss and improve the fuel economy. This paper explains a new approach methodology used for reducing the gearbox drag by 5- 10 %. This improvement can significantly contribute to the overall efficiency improvement thus carbon footprints of vehicle getting reduced. The following optimization areas are considered for such improvements, 1 Deflector @ various locations 2 Lubrication oil viscosity change 3 Preload optimized for the benefit of the power/drag loss, 4 Oil quantity changes to improve the power loss 5 Top cover

Senthil Raja, T., K, Barathi Raja, Kumar, Aneesh

Using Analysis of the Ring Pack and Piston to Optimize Oil Consumption of Current and Future Engines

2023-01-1603

10/31/2023

Engine manufacturers are increasingly concerned about oil consumption due to its implications for operating costs, emissions, and durability in both diesel and natural gas-powered engines. As future engines aim for low or near-zero emissions while utilizing low/zero carbon fuels, lubricant oil consumption will play a critical role in achieving decarbonization and emissions targets. Hydrogen-fuelled engines, in particular, will be more vulnerable to oil droplet and oil ash-based pre-ignition. Traditionally, the influence of key design parameters on oil consumption has been determined during the validation phase of an engine development program, which entails extensive testbed hours and time-consuming hardware iterations. As a result, development programs may be unable to optimize oil consumption due to cost and time constraints. The need to reduce oil consumption, along with these constraints, has prompted the adoption of more efficient development approaches, such as using virtual

Jay, Alastair, Ballard, Helen, Ocerin Meñica, Olatz, Larralde Yoller, Aitor, Barcena Ortiz de Urbina, Javier

The Effect of Sulfated Ash Content in Lubricant Oil on Particulate Emission of Gasoline Engine

2023-01-1647

10/31/2023

On a 1.5L TGDI gasoline engine bench(without GPF), 4 lubricant oils A/B/C/D with different sulfated ash content (1.1wt.%/0.8wt.%/0.7wt.%/0.5wt.%) were used to test the impact on the emission of PN and PM under WLTC condition. In the test results, the PN and PM values of Oil A are the largest, 7.12E+12 p/km and 2.60mg/km respectively, the PN and PM values of Oil B and C are the equivalent, 5.58E+12 p/km&5.72E+12 p/km,1.81 mg/km & 2.03 mg/km respectively, and the PN and PM values of Oil D are 5.38E+12 p/km and 1.65mg/km respectively. The test results indicate that the sulfated ash content of engine oil affects the particulate emission level of the engine. Oil with high sulfated ash content(1.1 wt.%) has high emission values(PN&PM); Oils with low sulfated ash content (0.8wt.%) have lower emission values (PN&PM). When the sulfated ash content of the oil is below 0.8wt.%, there is almost no significant difference in emission values (PN&PM).

Ling, Lei, Sun, Ruiyu, Xu, Jinshan

Drivetrain Lubricants with Efficiency-Boosting Properties For Electric Vehicles

2023-32-0143

09/29/2023

In electric vehicles (EVs), drivetrain lubricants are often utilized not only as a lubricating oil for the drivetrains but also for motor cooling. As such, they are required to both improve the efficiency of the drivetrains and to have a high cooling performance. Both requirements can be met by lowering the viscosity of the fluid, which effectively improves the heat transfer coefficient, reduces churning loss, and improves efficiency. However, low viscosity may adversely affect the fatigue life of gears and bearings. To address these issues, we used a high-performance base oil and optimized additives (e.g., anti-wear agents) to develop a fluid with higher lubricity than conventional automatic transmission fluid (ATF), even though its viscosity is lower. The 100,000-kilometer (WLTC mode) endurance test on an actual vehicle confirmed that there was no damage in the reduction gear unit parts. We also evaluated the torque loss on the reduction gear unit and fuel consumption and confirmed a

Matsui, Noriyuki, Matsuki, Shingo, Iino, Mari, Akiguchi, Junnosuke, Itou, Kimikazu, Saitou, Tomohito

Modeling of piston pin rotation in a large bore gas engine

2023-32-0161

09/29/2023

In an engine system, the piston pin is subjected to high loading and severe lubrication conditions, and pin seizures still occur during new engine development. A better understanding of the lubricating oil behavior and the dynamics of the piston pin could lead to cost- effective solutions to mitigate these problems. However, research in this area is still limited due to the complexity of the lubrication and the pin dynamics. In this work, a numerical model that considers structure deformation and oil cavitation was developed to investigate the lubrication and dynamics of the piston pin. The model combines multi-body dynamics and elasto-hydrodynamic lubrication. A routine was established for generating and processing compliance matrices and further optimized to reduce computation time and improve the convergence of the equations. A simple built-in wear model was used to modify the pin bore and small end profiles based on the asperity contact pressures. The model was then applied to a

Shu, Zhiyuan, Tian, Tian, Meng, Zhen, Fiedler, Rolf-Gerhard, Berbig, Frank

Investigation of Exhaust Particles on Different TEM Grids: a Comparison between Graphene Oxide and Silicon Nitride Grids

2023-32-0123

09/29/2023

Two different TEM (Transmission Electron Microscopy) grids - graphene oxide (GO) and silicon nitride (SiN) - were used to capture the particulates emitted with the exhaust of a modern 1.0 L GDI (Gasoline Direct Injection) engine. One speed-load condition (1250 rpm – idle) was chosen to generate a nanometric particulate output in the sub-23 nm regime which has been traditionally difficult to analyse in terms of composition and morphology. The overall aim was to understand if additional benefits can be obtained by analysing the particles captured in the exhaust on a nanoporous silicon nitride grid compared to state-of- the-art graphene oxide grids. The behaviour of porous SiN support films was of interest since nanopores are present in the grid in the 20 nm regime and the material is thermally and dimensionally stable under high temperatures, allowing thermophoretic capture directly within the engine exhaust stream. In addition to nanostructural and morphological comparison, the

Lagana, Salvatore, Akifjevs, Romans, Rocca, Antonino La, Cairns, Alasdair, Fay, Michael W., Webb, Kevin F.

Investigating the morphology and nanostructure of carbon black dispersed in lubricant oils and their impact on chain wear as a proxy of marginally lubricated components

2023-32-0116

09/29/2023

Excessive soot concentration in the lubricant promotes excessive wear on timing chains. The relationship between chain wear and soot concentration, morphology, and nanostructure, however, remains inconclusive. In this work, a chain wear test rig is used to motor a 1.3 L diesel engine following the speed profile of a Worldwide Harmonized Light Vehicle Test Cycle (WLTC). The lubricant oil was loaded with 3% carbon black of known morphology. The chain length is measured at regular intervals of 20 WLTC cycles (i.e. 10 hours) and the wear is expressed as a percentage of total elongation. Oil samples were collected and analysed with the same frequency as the chain measurements. Carbon black morphology and nanostructure were investigated using Dynamic Light Scattering (DLS) and Transmission Electron Microscopy (TEM). DLS data revealed carbon black particle size did not change substantially in the first 10 hours, however, during the remaining test cycles a reduction in agglomerates size over

Pacino, A., La Rocca, A., Kirkby, T., Reddyhoff, T., Cairns, A., Smith, J., Berryman, J., Fowell, M.

Effect of Viscosity Characteristics of Lubricants for Electric Vehicles on Thermal Conductivity and Gear Protection

2023-32-0144

09/29/2023

The purpose of this study is to investigate how the kinematic viscosity of lubricating oil used in hybrid electric vehicle (HEV) and electric vehicles (EV) transaxles affects thermal conductivity and gear seizure resistance. This study investigated the relationship between viscosity, thermal conductivity and gear seizure resistance in detail and found that thermal conductivity tends to decrease with decreasing viscosity. It was also found that the thermal conductivity decreases significantly after a certain viscosity. The relationship between viscosity and gear seizure resistance was also investigated and it was found that too low a viscosity causes a significant deterioration in gear seizure resistance.

Matsubara, Kazushige, Tatsumi, Hiroyuki, Nakahara, Yasuhito, Takekawa, Daisuke, Narita, Keiichi

Digital High-Speed Photography of Cavitation in Journal Bearings

2023-32-0163

09/29/2023

This paper presents current research comparing gaseous and vaporous cavitation in lubricant flows obtained by means of digital high-speed photography in un-precedented detail. Hydrodynamic journal bearings are compact and guarantee a nearly wear- resistant operation. These features make journal bearings the first choice for many applications. However, under particular operational conditions, e.g. a highly dynamic load, cavitation can occur which can lead to bearing failures. For the selected case of suction cavitation these conditions are characterized by high eccentricity combined with a rapid variation of the lubricating film thickness. The work at hand presents a new experimental approach to study suction cavitation in a scaled bearing model. Moreover, mechanical and fluid dynamic similarity laws are described which enable the transfer of bearing operation conditions into the model experiment and vice versa. An extensive literature research yields the parameters of operating

Reinke, Peter, Rienaecker, Adrian, Schmidt, Marcus, Beckmann, Tom

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