Refine Your Search

Topic

Author

Affiliation

Search Results

Video

Unsteady Simulation of Six-Inlet Pulsed-Flow Turbocharger Turbine

2020-09-14
The turbochargers are driven by unsteady, pulsating flow. Such flow is generated by the exhaust phase of an internal combustion engine (ICE). A lot of turbocharger simulations are done during steady-state operation. Such simulations are favorable for turbocharger optimization at a certain operating point. However, the frequency and amplitude of exhaust pulses can heavily influence turbine performance. This paper presents the results of the three-dimensional (3-D) simulations of the six-inlet turbocharger turbine, under pulsating operation with a moving mesh approach. One of the key points of interest was the separation of the pressure pulses from the six-exhaust pipes during engine operation. The leakage between the exhaust pipes was analyzed at each time step at the different turbine speed. Another key point was the turbine response during pulsating flow at the different rotor speed.
Video

Unsteady Simulation of Six-Inlet Pulsed Flow Turbocharger Turbine

2020-09-17
The turbochargers are driven by unsteady, pulsating flow. Such flow is generated by the exhaust phase of an internal combustion engine (ICE). A lot of turbocharger simulations are done during steady-state operation. Such simulations are favorable for turbocharger optimization at a certain operating point. However, the frequency and amplitude of exhaust pulses can heavily influence turbine performance. This paper presents the results of the three-dimensional (3-D) simulations of the six-inlet turbocharger turbine, under pulsating operation with a moving mesh approach. One of the key points of interest was the separation of the pressure pulses from the six-exhaust pipes during engine operation. The leakage between the exhaust pipes was analyzed at each time step at the different turbine speed. Another key point was the turbine response during pulsating flow at the different rotor speed.
Video

Three-Dimensional Multi-phase Physics-Based Modeling Methodology to Study Engine Cylinder-kit Assembly Tribology and Design Considerations- Part I

2020-09-16
Understanding cylinder-kit tribology is pivotal to durability, emission management, reduced oil consumption, and efficiency of the internal combustion engine. This work addresses the understanding of the fundamental aspects of oil transport and combustion gas flow in the cylinder kit, using simulation tools and high-performance computing. A dynamic three-dimensional multi-phase, multi-component modeling methodology is demonstrated to study cylinder-kit assembly tribology during the four-stroke cycle of a piston engine. The percentage of oil and gas transported through different regions of the piston ring pack is predicted, and the mechanisms behind this transport are analyzed. The velocity field shows substantial circumferential flow in the piston ring pack, leading to blowback into the combustion chamber during the expansion stroke.
Video

The Use of a Low Frequency Vibration Signal in Detecting the Misfire of a Cylinder of an Aircraft Piston Engine

2020-09-16
The following article describes the low frequency vibration analysis of aircraft piston engine Rotax 912 ULS. The results are based on the vibration signal made by the engine in the frequency range up to 400 Hz measured on the engine block in three axes. The aim of the research was to determine the method of detecting the misfire of individual cylinders based on the power spectrum of the selected frequencies analysis. Frequencies resulting from the periodicity of engine operation related to the frequency of the work cycle, rotational speed and ignition frequency were considered for the analysis. The tests were carried out in one point of operation. The highest levels of changes were recorded in the Y axis - the axis of piston movement. It was shown that the vibration level changes after switching off one of the cylinders.
Video

The Potential of Exhaust Waste Heat Use in a Turbocharged Diesel Engine for Charge Air Cooling

2020-09-17
Even a basic analysis of the use of fuel energy in a combustion engine would indicate that one-third of fuel energy is converted into exhaust waste, which is released into the environment. The scale of energy loss encourages scientists to try to consider the waste heat of exhaust gases as a potential source of useful energy. It is a standard today that waste heat is commonly used to power a turbocharger applied to internal combustion engines. Waste heat can also be used to drive an adsorption cooling system for air-conditioning inside the car. The drawback of that solution is complexity of the system and size of adsorption bed which make it not suitable for automotive industry use. The concept of increasing the capability of vehicles? turbo engines can boost performance of turbo-charged engines through extra cooling of air being impelled into the combustion chamber of the engine.
Video

The Influence of Reduxco Catalyst in the Diesel Fuel on Energy Parameters, Exhaust Gas Composition and Rate of Heat Release of a Diesel Engine

2020-09-17
According to the information provided by the catalyst producer, the catalyst with the trade name Reduxco, which was used in the research, is a reaction product of acetic acid, iron, n-butanol, n-propanol and isopropanol. According to Customer data, Reduxco catalyst in a fuel causes a decrease of the energy of activation of the hydrocarbon fuel oxidation reaction, introduces additional OH groups allowing to increase the burning rate, facilitates the combustion of already formed solid particles in the engine cylinder.
Video

Teardown-Based Cost Assessment for Use in Setting Greenhouse Gas Emissions Standards

2012-06-18
The U.S. Environmental Protection Agency (EPA) contracted with FEV, Inc. to estimate the per-vehicle cost of employing selected advanced efficiency-improving technologies in light-duty motor vehicles. The development of transparent, reliable cost analyses that are accessible to all interested stakeholders has played a crucial role in establishing feasible and cost effective standards to improve fuel economy and reduce greenhouse gas (GHG) emissions. The FEV team, together with engineering staff from EPA's National Vehicle and Fuel Emissions Laboratory, and FEV's subcontractor, Munro & Associates, developed a robust costing methodology based on tearing down, to the piece part level, relevant systems, sub-systems, and assemblies from vehicles ?with and without? the technologies being evaluated.
Video

Study on the Pre-Chamber Fueling Ratio Effect on the Main Chamber Combustion Using Simultaneous PLIF and OH* Chemiluminescence Imaging

2020-09-17
Pre-chamber combustion (PCC) enables leaner air-fuel ratio operation by improving its ignitability and extending flammability limit, and consequently, offers better thermal efficiency than conventional spark ignition operation. The geometry and fuel concentration of the pre-chamber (PC) is one of the major parameters that affect overall performance. To understand the dynamics of the PCC in practical engine conditions, this study focused on (i) correlation of the events in the main chamber (MC) with the measured in-cylinder pressure traces and, (ii) the effect of fuel concentration on the MC combustion characteristics using laser diagnostics. We performed simultaneous acetone planar laser-induced fluorescence (PLIF) from the side, and OH* chemiluminescence imaging from the bottom in a heavy-duty optical engine. Two different PC Fueling Ratios (PCFR, the ratio of PC fuel to the total fuel), 7%, and 13%, were investigated. The ?negative?
Video

Study on Fuel Efficiency and Durability Aspect of a Low Viscosity Heavy Duty Diesel Engine Oil

2020-09-17
In order to meet Corporate Average Fuel Economy (CAF�) regulations and Bharat Stage VI (BS VI) emission regulations, Indian auto original equipment manufacturers (OEMs) are adopting low viscosity engine/axle/transmission oils to achieve overall fuel efficiency gain. Attaining fuel economy by reducing oil viscosity is already established for passenger car motor oils (PCMOs) but is in its initial phase for heavy-duty diesel engine oils (HDDEOs). Now SAE 15W-40 is the most widely used viscosity grade by volume for HDDEO. In India, a large number of old vehicles meeting BS II, BS III and BS IV norms exists and require sustainable strategy to reduce fuel consumption, as well as overall greenhouse gas emissions. In this paper, authors discussed the development of low viscosity heavy duty diesel engine oil in 10W-30 viscometrics meeting API CH4 specification.
Video

Stereoscopic Micro-PIV Measurement of Near-Wall Velocity Distribution in Strong Tumble Flow under Motored SI Engine Condition

2020-09-17
In a state-of-the-art lean-burn spark ignition engine, a strong in-cylinder flow field with enhanced turbulence intensity is formed, and understanding the wall heat transfer mechanism of such a complex flow is required. The flow velocity and temperature profiles inside the wall boundary layer are strongly related to the heat transfer mechanism. In this study, two-dimensional three-component (2D3C) velocity distribution near the piston top surface was measured during the compression stroke in a strong tumble flow using a rapid compression and expansion machine (RCEM) and a stereoscopic micro-PIV system. The bore, stroke, compression ratio, and compression time were 75 mm, 128 mm, 15, and 30 ms (equivalent to 1000 rpm), respectively. A double-pulse Nd:YAG laser sheet was introduced from the intake side, and PIV images were captured near the piston surface around the TDC under motored conditions with a measurement region of 5.2 mm ? 6.9 mm (1200 ?
Video

Spotlight on Design: Sensors: Miniaturization and Testing

2015-04-15
“Spotlight on Design” features video interviews and case study segments, focusing on the latest technology breakthroughs. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. Accurate data is critical for the testing and development of parts and systems for cars, trucks, and airplanes. To obtain this data, engineers rely on high-end specialty sensors that can fit into cramped spaces and operate reliably under extreme heat and pressure. In the episode “Sensors: Miniaturization and Testing” (21:02), AVL engineers explain how a new crystalline material was developed to accurately measure the high pressures in the combustion chamber of turbocharged engines, and Meggitt Sensing Systems profiles the world’s smallest triaxial IEPE accelerometer.
Video

Sludge and Varnish Evaluation of Polyether Amine Gasoline Fuel Additives at ?Complete Fuel System Cleaner? Aftermarket Fuel Additive Concentrations

2020-09-17
Sludge and Varnish deposits that can build up in the crankcase originate in large part from fuel and fuel components that enter the crankcase through blow-by. These deposits can lead to a variety of engine issues including piston skirt deposits, cylinder bore scuffing, stuck lifters and oil filter plugging. A test has been developed to evaluate the contribution of ?Complete Fuel System Cleaner? (CFSC) aftermarket fuel additives to crankcase sludge and varnish deposit formation. CFSC aftermarket fuel additives are typically formulated with polyether amine (PEA) chemistry and at concentrations that exceed 2000ppm. Three different commercially-available CFSC products were tested, containing two different classes of PEA chemistry - propylene oxide-based PEA (?PO-PEA?) and butylene oxide-based PEA (?BO-PEA?). Two of the three products contained the same PO-PEA chemistry, but at different concentrations, to show the effect of additive dosage.
Video

Simulative Assessment of Injectors Placement and the Thermodynamic Effects of Gasoline Injection and Combustion in a Direct Dual Injection System

2020-09-17
The paper concerns the analysis of the combustion and exhaust emission phenomena in a direct gasoline dual injection system of a SI engine for various symmetrical injector placement parameters in the combustion chamber. Achieving a good combustion process is shaped by the direct fuel injection process, whose parameters vary. The novel direct injection system, which deploys two direct injectors mounted symmetrically, was subjected to this simulative research. This article focuses on the aspect of spatial and angular position of injectors in order to perform injection and achieve fuel combustion. The injector's pseudo-optimal location has been presented along with several changed positions (3 values of injector inset: 0, 1 and 2 mm, 3 values of injector distance from the cylinder axis: 16, 17, 18 mm and 3 values of angle between injector and the cylinder axis: 42.5, 45 and 47.5 degrees - 27 combinations altogether).
Video

Simulation Study of Force Distribution in the Multiple Linkage System of a Spark Ignition Engine Operating in the Atkinson Cycle

2020-09-17
The tests were carried out on an 3D engine model with an unconventional multiple linkage system. Compared to a classic crankset, the mechanism consists of more elements. In this multiple linkage system the camshaft, the piston rod and the main rod are connected to one common element. The camshaft rotating during operation at twice the speed of the crankshaft makes possible to achieve different piston stroke lengths with each revolution. With proper synchronization of the camshaft revolution with the crankshaft, the suction and compression stroke is smaller in relation to the expansion and exhaust strokes. For this reason, the Atkinson cycle was obtained without interfering with the variable valve timing. The thermal cycle is characterized by increased theoretical thermal efficiency. Due to the unique mechanism, the piston movement has different characteristics compared to classic solutions. Therefore, work was undertaken to analyze the distribution of forces in the system.
Video

SAE Eye on Engineering: Lexus Unveils Door Cameras on new ES300h

2020-02-28
Replacing conventional door-mounted mirrors with compact cameras is a future trend that�s finally arrived. In this episode of SAE Eye on Engineering, Editor-in-Chief Lindsay Brooke looks at the new door cameras on the Lexus ES300h. SAE Eye on Engineering also airs Monday mornings on WJR 760 AM Detroit's Paul W. Smith Show.
Video

Research of the Gas Fuel Supply Process on the Compression Stroke in Ship?s Low-Speed Gas-Diesel Engines

2020-09-15
In connection with the tightening of environmental standards, the leading manufacturers of marine low-speed engines are carrying out intensive work on their conversion to gas fuels. Due to the design features in this class of engines, only internal mixture formation is possible. For the organization of which two different approaches are possible. To date, only two are currently implemented. MAN started production of engines with gas fuel supply to the working cylinder under high pressure at the end of the compression stroke, and WinGD under low pressure at the beginning of the compression stroke. The analysis, performed by the authors, showed, that increasing the pressure before the gas supplying mechanisms to 3.5...6.0 MPa can reduce the residence time of the gas-air mixture in the working cylinder and reduce the likelihood of detonation combustion.
Video

Reduced Order Modeling of Engine Transients for Gasoline Compression Ignition Combustion Control

2020-09-16
This work focuses on reducing the computational effort of a 0-dimensional combustion model developed for compression ignition engines operating on gasoline-like fuels. As in-cylinder stratification significantly contributes to the ignition delay, which in turn substantially influences the entire gasoline compression ignition combustion process, previous modeling efforts relied on the results of a 1-dimensional spray model to estimate the in-cylinder fuel stratification. Insights obtained from the detailed spray model are leveraged within this approach and applied to a reduced order model describing the spray propagation. Using this computationally efficient combustion model showed a reduction in simulation time by three orders of magnitude for an entire engine cycle over the combustion model with the 1-dimensional spray model.
Video

Predictive Models of Intake Valve and Combustion Chamber Deposit Formation Tendency Based on Gasoline Fuel Composition

2020-09-15
Internal engine deposits are predominantly the product of incomplete combustion of fuel and have the potential to negatively impact engine performance and exhaust emissions. The ability to expeditiously screen fuels for their deposit formation tendency would be advantageous. This paper presents Partial Least Squares (PLS) computational models with the ability to predict the degree of deposit formation tendency from the hydrocarbon composition of gasoline fuels. Furthermore, the relationship between gasoline fuel and Intake Valve Deposits (IVD) and Combustion Chamber Deposits (CCD) that form in Port Fuel Injected (PFI) engines is explored. The models utilize detailed hydrocarbon analysis (DHA) to resolve the complex mixture of hydrocarbons for different model fuels, which are correlated to ten years of engine data collected from a port fuel injected engine.
Video

Polycarbonate Glazing - Accelerated Wiper Testing, Surface Characterization and Comparison with On-Road Fleet Data

2012-05-23
Exatec� PC glazing technology team, has developed advanced weathering and abrasion resistant coatings technology that can be applied to protect polycarbonate. It is of particular interest to quantify and understand the factors that determine the surface abrasion performance of coated PC in rear window and backlight applications that have a wiper system. In the present study we describe Exatec's lab scale wiper testing equipment and test protocols. We also describe adaptation of optical imaging system to measure contrast and nano-profiling using nano-indenter, as post wiper surface characterization methods. These methods are more sensitive to fine scratches on glazing surface than standard haze measurement and mechanical profilometry. Three coating systems were investigated; Siloxane wetcoat (A), Siloxane wetcoat (B), and Siloxane wetcoat (B) plus plasma coat (Exatec� E900 coating). The performance comparisons were made using all these surface characterization methods.
X