V6 Diesel Engine Research Articles

Multi-objective optimization of tribological properties of camshaft bearing pairs using DNN coupled with NSGA-II algorithm and TOPSIS

PurposeThis study aims to propose an optimization framework using deep neural networks (DNN) coupled with nondominated sorting genetic algorithm II and technique for order preference by similarity to an ideal solution method to improve the tribological properties of camshaft bearing pairs of internal combustion engine.Design/methodology/approachA lubrication model based on the theory of elastohydrodynamic lubrication and flexible multibody dynamics was developed for a V6 diesel engine. Setting DNN model as fitness function, the multi-objective optimization genetic algorithm and decision-making method were used to optimize the bearing pair structure with the goal of minimizing the total friction loss and the difference of the average values of minimum oil film thickness.FindingsThe results show that the lubrication state corresponding to the optimized bearing pair structure is elastohydrodynamic lubrication. Compared with the original structure, the optimized structure significantly reduces the total friction loss.Originality/valueThe optimized performance and corresponding structural parameters are obtained, and the optimization results were verified through multibody dynamics simulation.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2023-0417/

Lubrication failure analysis of camshaft bearings in V6 diesel engine

This contribution investigates the lubrication characteristics and failure causes of camshaft bearings belong to a V6 diesel engine. Numerical simulation based on the theory of elastohydrodynamic lubrication and flexible multibody dynamics is performed to analyse the lubrication characteristics of camshaft bearings. The results reveal that lubrication performance of different bearings of camshaft shows great differences. For a certain bearing, the mixed lubrication state and elastohydrodynamic lubrication state alternately occur in one engine cycle. The duration of mixed lubrication varies greatly in different bearings. For the bearing closest to the timing drive gear, the total pressure is dominated by the asperity contact pressure, and the predicted safety factors of the asperity contact pressure, hydrodynamic pressure and oil film thickness are less than 1, which means that this bearing will have lubrication failure.

Assessment of the impact of the number and the arrangement of cylinders of the KAMAZ disel engines on their fuel efficiency

Most of the natural aspirated truck diesel engines had an eight-cylinder V-twin (V8) configuration. Modern turbocharged diesel engines have a six-cylinder in-line configuration (L6), although some V8 diesel engines continue to be produced. A comparison was made of the performance of the KAMAZ-740 (V8) diesel engine with two turbochargers and KAMAZ-910 (L6) diesel engines with one turbocharger, having almost the same displacement with the same pattern of torque along the full load characteristic. The AVL BOOST software and experimental compressor and turbine maps were used. The factors influencing fuel efficiency were analyzed: indicated efficiency, friction and gas exchange losses, turbocharger efficiency. The L6 diesel engine had a uniform pressure pulsation in the exhaust manifold and at the turbine inlet. In the V8 diesel engine, the pulsations were uneven and had higher amplitude, which led to higher gas exchange losses and a decrease in turbine efficiency. The L6 diesel engine had a higher indicated efficiency but also higher friction losses. On average, the brake specific fuel consumption of the L6 diesel engine was by 5.5 % lower than that of the V8 diesel engine. Keywords V8 and P6 diesel engines; modeling in AVL BOOST; pressure pulsations in the exhaust system; turbocharger efficiency; friction and gas exchange losses

Study on heavy-duty journal bearing lubrication based on Elasto-hydrodynamic lubrication method

Main bearing wear failure to become one of the main factors affecting the service-life of the engine, so it is necessary to form the effective analysis of the main bearing lubrication method, which is used in the design of main bearing lubrication and friction. In this paper, the model of substructure of V8 diesel engine is built based on flexible multi-body dynamics, the various nonlinear factors in the process of engine working process are considered, and the EHD of main bearings is analysed by the EXCITE software. On the basis of the V8 engine model, the bearing load and lubrication performances of different poly- condensation of main bearing are compared. The main bearing lubrication properties of the analysis results can be used for the engine lubrication system design and optimization.

A general approach to tune the vibration properties of the mounting system in the high-speed and heavy-duty engine

The majority of the current research on the mounting system has emphasised on the low/medium power engine, rare work has been reported for the high-speed and heavy-duty engine, the vibration characteristics of which exhibits significantly increased complexity and uncertainty. In this work, a general dynamics model was firstly established to describe the dynamic properties of a mounting system with various numbers of mounts. Then, this model was employed for the optimization of the mounting system. A modified Powell conjugate direction method was developed to improve the optimization efficiency. Basing on the optimization results obtained from the theoretical model, a mounting system was constructed for a V6 diesel engine. The experimental measurement of the vibration intensity of the mounting systems shows excellent agreement with the theoretical calculations, indicating the validity of the model. This dynamics model opens a new avenue in assessing and designing the mounting system for a high-speed and heavy-duty engine. On the other hand, the delineated dynamics model, and the optimization algorithm should find wide applications for other mounting systems, such as the power transmission system which usually has various uncertain mounts.

Cylinder Pressure-Based Combustion Controls for Advanced Diesel Combustion With Multiple-Pulse Fuel Injection

For current diesel engines, multiple fuel injection mechanisms enabled by high rail-pressure systems is a key lever that can help to achieve further reduction in engine-out emissions and improvements in performance. In the case of multiple fuel injections, timing and fuel pulse-width for each pulse (or, equivalently, fuel amount) need to be optimized and maintained for low emissions, fuel economy, noise, and exhaust thermal management over different operating ranges. This paper presents a research study on the application of pressure-based controls for management of the multiple-pulse fuel injection, particularly main and post injections, to maintain a robust combustion behavior against disturbances and variations in the field. Several control features for simultaneous management of main and post injections are proposed and experimentally validated on a 6.6 L V8 diesel engine in an engine dynamometer, both at steady-state and during federal test procedure transients.

Cold and Warm Start Characteristics using HVO and RME Blends in a V6 Diesel Engine

Cold and Warm Start Characteristics using HVO and RME Blends in a V6 Diesel Engine

Some advantages and challenges of running a Euro IV, V6 diesel engine on a gasoline fuel

Previous work has demonstrated that single-cylinder CI engines, with relatively modest changes to operating conditions over a wide operating range, can be run with both very low NOx and low smoke as well as at high efficiency on fuels with high resistance to autoignition such as gasoline. The purpose of this work was to run a multi-cylinder engine without any major changes to the engine system on a gasoline fuel at constant fuel demand to get better understanding of the possible practical advantages and challenges. A 2.7dm3 Euro IV V6 diesel engine was run on a European standard diesel fuel of 54 CN (Cetane Number) according to the engine map at 1000rpm and 1500rpm at different loads. At the same speeds and loads, it was also run on a 84 RON gasoline but with different injection strategies and operating parameters, such as EGR levels. With gasoline, NOx levels comparable to the diesel map point could be obtained but at lower EGR rates, at lower injection pressures and lower brake specific fuel consumption and with extremely low smoke; however the CO and HC emissions were higher. The engine could not be run at high speeds or at loads greater than 12bar IMEP on gasoline because, without introducing modifications, the fuel overheated and gave rise to vapour-lock problems. Also at high loads, in order to limit NOx emissions, high EGR rates were required but the CO levels were excessive, because the particular turbocharger could not deliver adequate intake pressure at such conditions and hence the intake oxygen levels were too low. Thus further modifications to the fuel system and an alternative turbocharger would be needed to extend the operating range on gasoline. There appears to be potential for simplifying future CI engines e.g. by using lower injection pressures and replacing lean NOx after-treatment by CO and HC control by using gasoline-like fuels.

Multiphase CFD–CHT optimization of the cooling jacket and FEM analysis of the engine head of a V6 diesel engine

The present paper proposes a numerical methodology aiming at analyzing and optimizing an internal combustion engine water cooling jacket, with particular emphasis on the assessment of the fatigue strength of the engine head.Full three-dimensional CFD and FEM analyses of the conjugate heat transfer and of the thermo-mechanical loading cycles are presented for a single bank of a currently made V6 turbocharged Diesel engine under actual operating conditions.A detailed model of the engine, consisting of both the coolant galleries and the surrounding metal components is employed in both fluid-dynamic and structural analyses to accurately mimic the influence of the cooling system layout on the thermo-mechanical behavior of the engine.In order to assess a proper CFD setup useful for the optimization of the thermal behavior of the engine, the experimentally measured temperature distribution within the engine head is compared to the CFD forecasts. Particular attention is paid to the modeling of the phase transition and of the vapor nuclei formation within the coolant galleries.Thermo-mechanical analyses are then carried out aiming at addressing the design optimization of the engine in terms of fatigue strength. Because of the wide range of thermal and mechanical loadings acting on the engine head, both high-cycle and low-cycle fatigue are considered. An energy-based multi-axial criterion specifically suited for thermal fatigue is employed in the low-cycle fatigue region (i.e. the combustion dome) while well-established multi-axial stress/strain-based criteria are adopted to investigate the high-cycle fatigue regions of the engine head (i.e. the coolant galleries).The proposed methodology shows very promising results in terms of point-wise detection of possible engine failures and proves to be an effective tool for the accurate thermo-mechanical characterization of internal combustion engines under actual life-cycle operating conditions.

A Thermodynamic Model for a Single Cylinder Engine with Its Intake/Exhaust Systems Simulating a Turbo-Charged V8 Diesel Engine

A Thermodynamic Model for a Single Cylinder Engine with Its Intake/Exhaust Systems Simulating a Turbo-Charged V8 Diesel Engine

Multibody System Dynamics Simulation of Loads in Main Bearings of Crankshafts

In this paper, as for the calculation of loads in main bearings in a crankshaft system, multibody system dynamics is used to simulate the dynamic characteristics of the system composed of flexible and rigid bodies, coupled with hydrodynamic lubrication analysis further. The multibody system model with flexible crankshaft of one V8 diesel engine is built in ADAMS software, in which the bearings are modeled as rigid constrained bearings and hydrodynamic bearings respectively. The resulted loads in main bearings using different models are compared. The results show that the deformation of crankshafts has great effect on the values of loads in main bearings, and the bearing loads in different directions tend to uniformity due to the hydrodynamic lubrication.

Nanoparticle number from biodiesel blends combustion in a common rail fuel injection system diesel engine equipped with exhaust gas recirculation

The paper presents characterisations of nanoparticle number in exhaust gases from biodiesel blends (B30, 30% of RME by volume with ultra low sulphur diesel fuel, ULSD) combustion in a V6 diesel engine equipped with a common rail fuel injection system. The engine was operated on three steady-state test points extracted from the New European Driving Cycle without engine hardware or the engine management system (EMS) modification. A fast differential mobility spectrometer was used to determine particle number size distribution based on electrical mobility equivalent diameter. The distribution was dependent on the engine operating condition and the rate of exhaust gas recirculation (EGR). The particle size in the nucleation mode from B30 combustion with and without EGR is smaller than that of ULSD while giving higher number concentration for all engine operating conditions tested. However, in the accumulation mode with and without EGR, the smaller sizes and the lower total numbers from B30 combustion were observed. For both fuels, EGR shows insignificant changes to the primary particle size but noticeable increase in particle size and number in the accumulation mode. In overall, compared to the ULSD case, the B30 combustion reduced particle size and lowered total particle number in exhaust gas emitted from the engine with EGR.

Effect of air intake pressure drop on performance and emissions of a diesel engine operating with biodiesel and ultra low sulphur diesel (ULSD)

The main objective of this research is to study the effect of the pressure drop in the inlet manifold, on the engine performance and exhaust emission system, the fuel used in this v6 diesel engine is Rapeseed Methy Ester (RME) and a comparison between (RME) fuel and ultra low sulphure diesel (ULSD) was conducted and a steady state test for both fuels were carried at BMEP 3.1 and 4.7 bar. At combustion process in terms of cylinder pressure and heat release, engine performance and exhaust emission were analysed, an experimental evidence showed that, pressure drop increasing in the intake manifold will increase the fuel consumption and reduces the engine efficincy by using both, RME and ULSD. Engine efficiency with RME is 1.2%- 2% lower than ULSD, having exhaust emiession level of NOx and CO slightly higher for RME comparing to ULSD. Emissions of unburned hydrocarbon for RME is much smaller than ULSD.

The New E-Class V6 Diesel Engine with BlueTEC

The New E-Class V6 Diesel Engine with BlueTEC

The New V8 Diesel Engine from MAN

MAN has developed a new V8 engine for the 16-l class with an output of 500 kW and 3,000 Nm of torque for its TGX and TGS ranges of heavy trucks. To reduce NOx, MAN has applied an SCR system with AdBlue injection. This article describes the engine concept, the design of the main components, the development of vehicle-specific add-on parts and the work carried out to optimise the combustion system and exhaust aftertreatment.

Bluetec — The concept for diesel engines with lowest emissions

In October 2006 when Mercedes-Benz introduced the model E 320 Bluetec, it brought the first production diesel passenger car to the market that met US Tier 2 Bin8 emission standards. Mercedes-Benz will continue its Bluetec offensive in 2008, offering the V6 diesel engine in the M, GL and R Classes in the USA, using the SCR/AdBlue technology which meets the US Tier 2 Bin5 emission standards and thereby all currently valid emission standards for diesel passenger cars worldwide.

New engine design excludes manifolds

The new Duramax V8 diesel engine introduced by General Motors that has been exhibited to the press is interesting in that there are no inlet or exhaust manifolds.

The new V8 diesel engine for Land Rover

After the launch of the 2.7-l TDV6 diesel engine for Jaguar, Land Rover and PSA in the spring of 2004, here is a new member of the engine family. The new 3.6-l TDV8 Diesel engine was developed for Land Rover’s Range Rover and Range Rover Sport models. The premium market segment positioning demands the best possible attributes from the engine, particularly torque as well as engine acoustics. According to the Land Rover specific requirements, the engine is fully off road capable and can be used in all world markets. The engine fulfills the Euro 4 emissions requirements and will be available with a regulated particle filter.

A statistical measure of the non-proportionality of stresses – investigations and applications*

Abstract In mechanical engineering, fatigue assessment based on Finite Element analysis of components, where complex non-proportional loads are acting on, plays an important role in identifying critical spots, and predicting the lifetime, till crack initiation. In this contribution the life time analysis of a dynamically loaded crankshaft of a V6 diesel engine is demonstrated. Finite Element method, multi-body system simulation and an elasto-hydrodynamic simulation of the oil film have been combined for a modal analysis in the frequency domain. Based on these results a fatigue analysis follows to identify the critical engine speed range. In notches rotating principal stresses can be found, which reduce the lifetime significantly. To quantify the non-proportionality of stresses and the resulting decrease of the fatigue limit, a statistical measure originally proposed by Chu et al. is applied. The critical plane criterion has been used in conjunction with a stress based method (concept of synthetic S/N-curves, influence parameter concept) and linear damage accumulation according to Miner's rule.

Aluminium cylinder crankcase for V6-diesel engines from Daimler-Chrysler

Based on many years experience in the production of cylinder crankcases, which have been supplied to customers in the European and North American markets since 1994, Hydro Aluminium Alucast GmbH, Dillingen, is now the partner of Daimler-Chrysler for the manufacture of cylinder crankcases for a new V6 diesel engine, volume-produced using the CPS-core package system. The engine replaces the five and six cylinder in-line engines previously used in all Mercedes-Benz models, from the C- to the S-Class. The new power unit, which will also be used in Chrysler vehicles, represents a milestone in the compact lightweight construction of diesel engines.