4,943 research outputs found

    Performance analysis of turbocharger effect on engine in local cars

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    The performance of a gasoline-fueled internal combustion engines can be increased with the use of a turbocharger. However, the amount of performance increment for a particular engine should be studied so that the advantages and drawbacks of turbocharging will be clarified. This study is mainly concerned on the suitable turbocharger unit selection, engine conversions required and guidelines for testing a Proton 4G92 SOHC 1.6-litre naturally aspirated gasoline engine. The engine is tested under its stock naturally aspirated condition and after been converted to turbocharged condition. The effect of inter cooled turbocharged condition is also been tested. Boost pressure is the main parameter in comparing the performance in different conditions as it influences the engine torque, power, efficiency and exhaust emissions. The use of a turbocharger on this test engine has clearly increased its performance compared to its stock naturally aspirated form. The incorporation of an intercooler to the turbocharger system increases the performance even further. With the worldwide effort towards environmental-friendly engines and fossil fuel shortage, the turbocharger can help to create engines with enhanced performance,minimum exhaust emissions and maximum fuel economy

    A finite element approach for the implementation of magnetostrictive material terfenol-D in automotive CNG fuel injection actuation

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    Magnetostriction is the deformation that spontaneously occurs in ferromagnetic materials when an external magnetic field is applied. In applications broadly defined for actuation, magnetostrictive material Terfenol-D possesses intrinsic rapid response times while providing small and accurate displacements and high-energy efficiency, which are some of the essential parameters required for fast control of fuel injector valves for decreased engine emissions and lower fuel consumption compared with the traditional solenoid fuel injection system. A prototype CNG fuel injector assembly was designed, which primarily included magnetostrictive material Terfenol-D as the actuator material, 1020 Steel having soft magnetic properties as the injector housing material, AWG copper wire as the coil material and 316 Stainless Steel having non-magnetic properties as the plunger material. A 2D cross-sectional geometry including the injector housing, coil, Terfenol-D shaft, and plunger, was modeled in both Finite Element Method Magnetics (FEMM) and ANSYS for 2D axisymmetric magnetic simulation. The magnetic simulations were performed in order to determine the coil-circuit parameters and the magnetic field strength to achieve the required magnetostrictive strain, and consequently, the injector needle lift. The FEMM magnetic simulations were carried out with four different types of AWG coil wires and four different injector coil thicknesses in order to evaluate the relationship between the different coil types and thicknesses against the achieved strain or injector lift. Eventually, the optimized parameter obtained from FEMM results analysis was verified against ANSYS electromagnetic simulation. Subsequently, a three dimensional replica of the CNG flow conduit was modelled in GAMBIT with the resultant injector lift. The meshed conduit was then simulated in FLUENT using the 3D time independent segregated solver with standard k-ε, realizable k-ε and RSM turbulent models to predict the mass flow rate of CNG to be injected. Eventually, the simulated flow rates were verified against mathematically derived static flow rate required for a standard automotive fuel injector considering standard horsepower, BSFC and injector duty cycle

    Microwave Enhanced Combustion on a Constant Volume Combustion Chamber for Lean Combustion and EGR Dilution

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    The effect of microwave enhancement on combustion was investigated using a spherical, constant-volume combustion chamber. Microwave energy at 2.45 GHz was coupled into the spherical chamber using a quarter-wavelength dipole antenna. Standing waves of high-strength electrical fields were created to enhance the flames ignited by a spark plug. Pressure traces of combustion with and without microwaves were recorded to compare the combustion improvements. Microwave power levels and discharge durations were also varied to understand their impact on the level of improvement. Results indicated that the microwave system can effectively accelerate combustion and improve cycle stability for dilute combustion, including lean burn at about 0.8 equivalence ratio and stoichiometric operation with 20% exhaust gas recirculation (EGR) dilution

    Prospects of lean ignition with the quarter wave coaxial cavity igniter

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    New ignition sources are needed to operate the next generation of lean high efficiency internal combustion engines. A significant environmental and economic benefit could be obtained from these lean engines. Toward this goal, the quarter wave coaxial cavity resonator, QWCCR, igniter was examined. A detailed theoretical analysis of the resonator was performed relating geometric and material parameters to performance characteristics, such as resonator quality factor and developed tip electric field. The analysis provided for the construction and evaluation of a resonator for ignition testing.;The evaluation consisted of ignition tests with liquefied-petroleum-gas (LPG) air mixtures of varying composition. The combustion of these mixtures was contained in a closed steel vessel with a precombustion pressure near one atmosphere. The resonator igniter was fired in this vessel with a nominal 150 W microwave pulse of varying duration, to determine ignition energy limits for various mixtures. The mixture compositions were determined by partial pressure measurement and the ideal gas law. Successful ignition was determined through observation of the combustion through a view port. The pulse and reflected microwave power were captured in real time with a high-speed digital storage oscilloscope. Ignition energies and power levels were calculated from these measurements. As a comparison, these ignition experiments were also carried out with a standard non-resistive spark plug, where gap voltage and current were captured for energy calculations.;The results show that easily ignitable mixtures around stoichiometric and slightly rich compositions are ignitable with the QWCCR using the similar kinds of energies as the conventional spark plug in the low milli-Joule range. Energies for very lean mixtures could not be determined reliably for the QWCCR for this prototype test, but could be lower than that for a conventional spark. Given the capability of high power, high energy delivery, and opportunity for optimization, the QWCCR has the potential to deliver more energy per unit time than a conventional spark plug and thus should be considered be as a lean ignition source

    Influence of plasma-assisted ignition on flame propagation and performance in a spark-ignition engine

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    Lean-burn is an attractive concept for reasons of high thermal efficiency and low nitrogen oxide (NOx) emissions, however, successful implementation in spark-ignition (SI) engines turned out to be challenging because of misfire or partial burn caused by attenuated flame propagation. In order to overcome this issue, microwave-assisted plasma ignition system (MAPIS) has been applied in combustion systems. The MAPIS consists of a conventional ignition coil, a non-resistor spark plug, a mixing unit, a waveguide, and a magnetron (2.45GHz, 3kW). A series of experiments was carried out to understand discharge characteristics and to validate its performance in a constant volume vessel as well as in a single-cylinder spark-ignition engine. The fundamental investigation based on optical emission spectroscopy and flame imaging showed that the ejection of the microwave was beneficial to produce more reactive species such as OH and O radicals thanks to higher electron temperature than conventional spark ignition. The lean limit was able to be extended up to an equivalence ratio of 0.5 based on a larger initial flame kernel size with MAPIS in the vessel test. Meanwhile, in the engine test, combustion stability was noticeably improved showing smaller cycle-to-cycle fluctuations in in-cylinder pressure. Improvement in fuel efficiency up to 6% could be achieved by stable operation under fuel-lean conditions. In terms of emissions, MAPIS was advantageous to reduce carbon monoxide (CO) emissions by promoting more complete combustion

    Meta-heuristic algorithms in car engine design: a literature survey

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    Meta-heuristic algorithms are often inspired by natural phenomena, including the evolution of species in Darwinian natural selection theory, ant behaviors in biology, flock behaviors of some birds, and annealing in metallurgy. Due to their great potential in solving difficult optimization problems, meta-heuristic algorithms have found their way into automobile engine design. There are different optimization problems arising in different areas of car engine management including calibration, control system, fault diagnosis, and modeling. In this paper we review the state-of-the-art applications of different meta-heuristic algorithms in engine management systems. The review covers a wide range of research, including the application of meta-heuristic algorithms in engine calibration, optimizing engine control systems, engine fault diagnosis, and optimizing different parts of engines and modeling. The meta-heuristic algorithms reviewed in this paper include evolutionary algorithms, evolution strategy, evolutionary programming, genetic programming, differential evolution, estimation of distribution algorithm, ant colony optimization, particle swarm optimization, memetic algorithms, and artificial immune system

    In-Cylinder Diagnostics Using Feedback from Resonant Cavity Ignition Sources

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    The Quarter-Wave Coaxial Cavity Resonator (QWCCR) Plasma Igniter is a spark ignition replacement system based on a novel technology. This system creates coronal plasma through the use of radio frequency voltage step-up. Because this device is an open loop resonant structure, it is sensitive to changes in the environment it operates in, the physical and the combustion environment. A relationship can be developed between the effects of the pressure in the combustion environment and the changes in resonance frequency experienced by the igniter. These diagnostic capabilities can be utilized to detect and alleviate misfires, incomplete fuel burns, etc. in an engine cycle.;A series of tests were conducted to prove these principles. The QWCCR plasma igniter was inserted into the Cooperative Fuel Research (CFR) test engine. Data was collected via an in-cylinder pressure computer and a network analyzer. The engine was set at different increments in crank angle to map the changes in the parameters at different volumes throughout the compression and power strokes. During these tests there was no fuel or combustion only air as the medium in-cylinder.;The results compare a baseline frequency calculated from the in-cylinder pressure data and an experimental frequency that was collected using the network analyzer. The percent error between these two is at a maximum 1.725%. Three-dimensional plots were created from this data to show that frequency and pressure can be predicted and to show that this is a valid means of tracking changes in the combustion chamber. The results demonstrate that QWCCR Plasma igniter can be used as a diagnostics tool. This validation provides numerous additional opportunities for diagnostic capabilities using the other fundamental parameters of the igniter physical and electro-magnetic properties

    Assessing the Potential for Improved Scramjet Performance through Application of Electromagnetic Flow Control

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    Hypersonic flight using scramjet propulsion bridges the gap between turbojets and rockets. Recent efforts focus on magnetogasdynamic (MGD) flow control to mitigate the problems of high thermomechanical loads and low efficiencies associated with scramjets. This research is the first flight-scale, three-dimensional computational analysis of a realistic scramjet to assess how MGD flow control improves scramjet performance. Developing a quasi-one dimensional design tool culminated in the first open source scramjet geometry. This geometry was tested with the Air Force Research Laboratory\u27s electromagnetic computational code. To increase fidelity, an algorithm was developed to incorporate thermochemistry, resulting in the only open-source model of combustion in an MGD controlled engine. A control volume analysis with electron beam ionization was presented for the first time with this approach. Local MGD control within the inlet affected drag and heat transfer and was marginally successful in raising combustor inflow pressure. MGD acceleration to increase flow momentum was effective at improving flow into the scramjet\u27s isolator. Combustor-based MGD generators proved superior to inlet generators with respect to power density and engine efficiency. MGD acceleration was ineffective in improving performance with all the MGD engines having approximately 33% more drag than baseline and none of them achieving self-powered operation state

    Design and development of auxiliary components for a new two-stroke, stratified-charge, lean-burn gasoline engine

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    A unique stepped-piston engine was developed by a group of research engineers at Universiti Teknologi Malaysia (UTM), from 2003 to 2005. The development work undertaken by them engulfs design, prototyping and evaluation over a predetermined period of time which was iterative and challenging in nature. The main objective of the program is to demonstrate local R&D capabilities on small engine work that is able to produce mobile powerhouse of comparable output, having low-fuel consumption and acceptable emission than its crankcase counterpart of similar displacement. A two-stroke engine work was selected as it posses a number of technological challenges, increase in its thermal efficiency, which upon successful undertakings will be useful in assisting the group in future powertrain undertakings in UTM. In its carbureted version, the single-cylinder aircooled engine incorporates a three-port transfer system and a dedicated crankcase breather. These features will enable the prototype to have high induction efficiency and to behave very much a two-stroke engine but equipped with a four-stroke crankcase lubrication system. After a series of analytical work the engine was subjected to a series of laboratory trials. It was also tested on a small watercraft platform with promising indication of its flexibility of use as a prime mover in mobile platform. In an effort to further enhance its technology features, the researchers have also embarked on the development of an add-on auxiliary system. The system comprises of an engine control unit (ECU), a directinjector unit, a dedicated lubricant dispenser unit and an embedded common rail fuel unit. This support system was incorporated onto the engine to demonstrate the finer points of environmental-friendly and fuel economy features. The outcome of this complete package is described in the report, covering the methodology and the final characteristics of the mobile power plant
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