Current Issue : October - December Volume : 2016 Issue Number : 4 Articles : 6 Articles
Based on the compressible Navierââ?¬â??Stokes equations for reactive flow\nproblems, an eigenvalue problem for the steady and self-sustained premixed\ncombustion wave propagation is developed. The eigenvalue problem is analytically\nsolved and a set of analytic formulae for description of the wave propagation is\nfound out. The analytic formulae are actually the exact solution of the eigenvalue\nproblem in the form of integration, based on which author develops an iterative\nand numerical algorithm for calculation of the steady and self-sustained premixed\ncombustion wave propagation and its speed. In order to explore the mathematical\nmodel and test the computational method developed in this paper, three groups\nof combustion wave propagation modes are calculated. The computational results\nshow that the non-trivial modes of the combustion wave propagation exist and their\ndistribution is not continuous but discrete....
This document presents the development of a system for detecting faults through fuzzy logic,\nusing different parameters such as poorly combusted hydrocarbons (HC), Carbon Dioxide\n(CO2), engine speed (RPM), and Manifold Absolute Pressure Sensor (MAP) to predict the\nfaults that may occur in the engine. In order to determine the behavior of the inputs, there\nwere generated different faults in a sonata 2.0 gasoline engine, such as poorly calibrated spark\nplugs, improper fuel pressure, air filter and catalytic converter clogging. The input and output\nvariables are analyzed by fuzzy logic. Rules are generated for these variables, which will give\nlogical knowledge to the system; these proposed rules are verified through the system\nprogramming that is presented by simulink. Each input variable establishes a diverse output\nparameter. Through this system, it can be determined the level of the response parameters, which\nwill give reliable values for detecting the faults when performing corrective maintenance;\nconsequently, it will save time and money....
The current obstacles to the sustainable development\nof the vehicle fleet present one of the most serious and complex challenges\nfor technogenic civilization in view of the consumption of rapidly\ndepleting oil and gas resources and the increasing emissions\nof the products of fuel combustion. The aim of this paper is to study and\ndiscuss the impact patterns of the quality of fuel on the environmental and\nperformance characteristics of vehicles and to develop an approach\ntowards improving the quality of fuel as a means of increasing\nthe sustainability of vehicles. The patterns of influence of the chemical\ncomposition of the fuel on the temperature conditions in the engine,\nthe emissions of toxic substances and carbon dioxide from the fuel�s\ncombustion, the toxicity of the gasoline vapor, carbonization, fuel\nconsumption, engine power and the requirements for a gasoline octane\nrating have been identified. The use of a fuel additive has been proposed\nwhich improves fuel injection in the engines and excludes tarry deposits\nin the fuel system through the effective detergency and catalyzes\nthe gasification reactions in the engine. The developed fuel additive was\nshown to have a positive effect by significantly reducing fuel consumption\nand toxic emissions and improving the performance of vehicles....
New designs and adaptation methods are experimented to ensure compliance to ever increasing\nemissions and efficiency requirements of modern diesel engines. Piston head structure which influences\nthe mixing rate and timing of the fuel within in the combustion chamber is known to enable\nincrease in combustion efficiency and thus lower emission rates. In this paper, computation\nanalysis of flow within a diesel engine cylinder with a twin swirl combustion chamber design\nthroughout a full cycle is presented. The results obtained indicate that the effect of the twin swirl\ncombustion chamber on the cold flow conditions is noteworthy and further analysis together with\nexperiments may reveal information that may prove to be useful in further new designs....
Ignition of a combustible mixture by a transient jet of hot reactive gas is important for safety of mines, prechamber ignition in\nIC engines, detonation initiation, and novel constant-volume combustors. The present work is a numerical study of the hot jet\nignition process in a long constant-volume combustor (CVC) that represents a wave rotor channel. The hot jet of combustion\nproducts from a prechamber is injected through a converging nozzle into the main CVC chamber containing a premixed fuel-air\nmixture. Combustion in a two-dimensional analogue of the CVC chamber is modeled using a global reaction mechanism, a skeletal\nmechanism, or a detailed reaction mechanism for three hydrocarbon fuels: methane, propane, and ethylene. Turbulence is modeled\nusing the two-equation SST ...
For reduction of engine-out emissions and improvement of fuel economy, closed-loop control of the combustion process has been\nexplored and documented by many researchers. In the closed-loop control, the engine control parameters are optimized according\nto the estimated instantaneous combustion metrics provided by the combustion sensing process. Combustion sensing process is\nprimarily composed of two aspects: combustion response signal acquisition and response signal processing.As a number of different\nsignals have been employed as the response signal and the signal processing techniques can be different, this paper did a review\nwork concerning the two aspects: combustion response signals and signal processing techniques. In-cylinder pressure signal was\nnot investigated as one of the response signals in this paper since it has been studied and documented in many publications and\nalso due to its high cost and inconvenience in the application....
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