A Numerical Study of Spark Ignition

2004 ◽  
Author(s):  
O. Ekici ◽  
V. K. Bokka ◽  
O. A. Ezekoye ◽  
R. D. Matthews
Keyword(s):  
Chemical Kinetics ◽  
Numerical Study ◽  
Control Volume ◽  
Theoretical Models ◽  
Spark Discharge ◽  
Physical Models ◽  
Local Thermal Equilibrium ◽  
Energy Equations ◽  
Volume Method ◽  
Kinetics Of

We present theoretical models to simulate spark discharge and ignition. Two models are presented. The first model considers simplified fluid mechanics with chemistry effects. The second model utilizes more sophisticated flow with no chemistry. The simplified model incorporates physical models of breakdown and chemical kinetics of combustion with species and energy equations solved using a control volume method. A three-step mechanism is used to simulate chemical kinetics for fuel combustion and nitrogen chemistry. Dissociation and ionization in the plasma are included by assuming local thermal equilibrium. The second model simulates a spark discharge in air with more complete physics of flow using a high order numerical method, which shows the evolution of the shock wave and a torus-like plasma kernel.

scholarly journals Numerical study of the coupled natural convection with surface radiation in a cylindrical annular enclosure

2020 ◽  
Vol 330 ◽  
pp. 01029
Author(s):  
Mohamed Amine MEDEBBER ◽  
Abderrahmane AISSA ◽  
Belkacem OULD SAID ◽  
Noureddine RETIEL ◽  
Mohammed EL GANAOUI
Keyword(s):  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Surface Radiation ◽  
Navier Stokes ◽  
Simpler Algorithm ◽  
Energy Equations ◽  
Volume Method ◽  
Rayleigh Numbers ◽  
Total Average

The interaction of natural convection with thermal radiation of black surfaces in a cylindrical enclosure filled with air has been numerically investigated. The steady-state continuity, Navier-Stokes and energy equations were discretized using the control volume method and solved numerically via the SIMPLER algorithm. Effects of Rayleigh number (Ra), wall emissivity (εp) and height ratio parameter (X) are studied. The result shows that surface radiation significantly altered the temperature distribution and the flow patterns, especially at higher Rayleigh numbers. The total average Nusselt number has also been discussed for valuating heat transfer through the enclosure.

Effect of Periodic Imposed Heat Flux on Three-Dimensional Natural Convection in a Partially Heated Cubical Enclosure

2016 ◽  
Vol 831 ◽  
pp. 83-91
Author(s):  
Lahoucine Belarche ◽  
Btissam Abourida
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Study ◽  
Control Volume ◽  
Vertical Wall ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Cubical Enclosure ◽  
Simplec Algorithm ◽  
Volume Method

The three-dimensional numerical study of natural convection in a cubical enclosure, discretely heated, was carried out in this study. Two heating square sections, similar to the integrated electronic components, are placed on the vertical wall of the enclosure. The imposed heating fluxes vary sinusoidally with time, in phase and in opposition of phase. The temperature of the opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. The governing equations are solved using Control volume method by SIMPLEC algorithm. The sections dimension ε = D / H and the Rayleigh number Ra were fixed respectively at 0,35 and 106. The average heat transfer and the maximum temperature on the active portions will be examined for a given set of the governing parameters, namely the amplitude of the variable temperatures a and their period τp. The obtained results show significant changes in terms of heat transfer, by proper choice of the heating mode and the governing parameters.

scholarly journals The effect of surface regression on the downward flame spread over a solid fuel in a quiescent ambient

2007 ◽  
Vol 11 (2) ◽  
pp. 67-86 ◽  
Author(s):  
Mohammad Ayani ◽  
Javad Esfahani ◽  
Antonio Sousa
Keyword(s):  
Solid Fuel ◽  
Flame Spread ◽  
Solid Phase ◽  
Numerical Study ◽  
Control Volume ◽  
Staggered Grid ◽  
Navier Stokes ◽  
Gas Temperature ◽  
Arrhenius Kinetics ◽  
Energy Equations

The present work is addressed to the numerical study of the transient laminar opposed-flow flame spread over a solid fuel in a quiescent ambient. The transient governing equations - full Navier-Stokes, energy, and species (oxygen and volatiles) for the gas phase, and continuity and energy equations for the solid phase (fuel) with primitive variables are discretized in a staggered grid by a control volume approach. The second-order Arrhenius kinetics law is used to determine the rate of consumption of volatiles due to combustion, and the zero-order Arrhenius kinetics law is used to determine the rate of degradation of solid fuel. The equations for the fluid and solid phases are solved simultaneously using a segregated technique. The physical and thermo-physical properties of the fluid (air) such as density, thermal conductivity, and viscosity vary with temperature. The surface regression of the solid fuel is modeled numerically using a discrete formulation, and the effect upon the results is analyzed. The surface regression of the solid fuel as shown affects on the fuel surface and gas temperature, mass flux and velocity of volatiles on the top surface of fuel, total energy transferred to the solid phase, etc. It seems the results to be realistic. .

A Three-Dimensional Numerical Study of Tin Droplets Landing Sequentially on a Solid Surface

2002 ◽  
Author(s):  
R. Ghafouri-Azar ◽  
J. Mostaghimi ◽  
S. Chandra
Keyword(s):  
Surface Deformation ◽  
Numerical Study ◽  
Control Volume ◽  
Three Dimensional ◽  
Sequential Deposition ◽  
Free Surface Deformation ◽  
Energy Equations ◽  
Simulated Images ◽  
D Model ◽  
Shape And Size

A three-dimensional (3-D) model of spreading and solidification was used to investigate the sequential deposition of two tin droplets for different offset landing. Numerical simulations predicted the shape and size of the landing tin droplet as it spread over a previously landed splat. The model applies a fixed-grid Eulerian control volume to solve the fluid dynamics and energy equations. The Volume of Fluid (VOF) algorithm is used to track the free surface deformation. The comparison of the simulated images and experimental photographs validated the prediction of the model.

Cloud Computing Applied for Numerical Study of Thermal Characteristics of SIP

2013 ◽  
pp. 166-175
Author(s):  
S. K. Maharana ◽  
Praveen B. Mali ◽  
Ganesh Prabhakar ◽  
Sunil J ◽  
Vignesh Kumar
Keyword(s):  
Cloud Computing ◽  
Thermal Management ◽  
Integrated Circuit ◽  
Heat Dissipation ◽  
Numerical Study ◽  
Control Volume ◽  
Thermal Characteristics ◽  
Thermal Dissipation ◽  
Volume Method ◽  
Power And Energy

Thermal management of integrated circuit (IC) and system-in-package (SIP) has gained importance as the power density and requirement for IC design have increased and need exists to analyse the heat dissipation performance characteristics of IC under use. In this paper, the authors examine the thermal characteristics of materials of IC. The authors leverage Cloud Computing architecture to remotely compute the dissipation performance parameters. Understanding thermal dissipation performance, which explains the thermal management of IC, is important for chip performance, as well as power and energy consumption in a chip or SIP. Using architectural understanding of Software as a Service (SaaS), the authors develop an efficient, fast, and secure simulation technique by leveraging control volume method (CVM) of linearization of relevant equations. Three chips are kept in tandem to make it a multi-chip module (MCM) to realise it as a smaller and lighter package. The findings of the study are presented for different dimensions of chips inside the package.

Induction Heating of an Aluminum Billet: A Numerical Study of the Thermal Behavior

2011 ◽  
Vol 110-116 ◽  
pp. 4697-4704
Author(s):  
U. Ray ◽  
A. Sarkar ◽  
S. Sen ◽  
B. Roychowdhury ◽  
N. Barman
Keyword(s):  
Induction Heating ◽  
Source Term ◽  
Numerical Study ◽  
Control Volume ◽  
Momentum Conservation ◽  
Conservation Equation ◽  
Heating Process ◽  
Energy Conservation Equation ◽  
Transfer Behavior ◽  
Volume Method

In the present work, the heat transfer behavior during induction heating of a cylindrical aluminum billet is performed numerically. The heating process is represented by the energy conservation equation where the heat generation during heating is added as a volumetric source term. The evolution of latent heat during melting is also added as a volumetric source term. The continuity and the momentum conservation equations are considered to represent the flow field after melting starts. These governing equations are solved based on the control volume method. The enthalpy update scheme is used for evolution of melt-fraction during heating. The work predicts the evolution of temperature during heating, the distributions of temperature and melt-fraction in the domain. Subsequently, a parametric study is also performed.

Three-Dimensional Temperature Distribution in EHD Lubrication: Part II—Point Contact and Numerical Formulation

1993 ◽  
Vol 115 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Kyung-Hoon Kim ◽  
Farshid Sadeghi
Keyword(s):  
Temperature Distribution ◽  
Film Thickness ◽  
Numerical Study ◽  
Control Volume ◽  
Three Dimensional ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Lubricant Film ◽  
Numerical Formulation ◽  
Energy Equations

A numerical study of Newtonian thermal elastohydrodynamic lubrication (EHD) of rolling/sliding point contacts has been conducted. The two-dimensional Reynolds, elasticity and the three-dimensional energy equations were solved simultaneously to obtain the pressure, film thickness and temperature distribution within the lubricant film. The control volume approach was employed to discretize the differential equations and the multi-level multi-grid technique was used to simultaneously solve them. The discretized equations, as well as the nonorthogonal coordinate transformation used for the solution of the energy equation, are described. The pressure, film thickness and the temperature distributions, within the lubricant film at different loads, slip conditions and ellipticity parameters are presented.

Turbulent Free Convection in a Composite Enclosure

2003 ◽  
Author(s):  
Marcelo J. S. de Lemos ◽  
Viviani T. Magro
Keyword(s):  
Thermal Field ◽  
Control Volume ◽  
Simple Algorithm ◽  
Flow Region ◽  
Porous Matrix ◽  
Porous Substrate ◽  
Local Flow ◽  
Vertical Walls ◽  
Energy Equations ◽  
Volume Method

This paper deals with the problem of heat transfer in square cavities partially filled with porous material. Local flow and energy equations are integrated in a representative elementary volume in order to obtain a set of equations valid in both the clear flow region and in the porous matrix. A unique set of equations is discretized with the control volume method and solved with the SIMPLE algorithm. Enhancement of convective currents within the porous substrate is detected as the Rayleigh number increases. Thin boundary layers along the cavity vertical walls and stratification of the thermal field are observed for Ra > 109.

scholarly journals Numerical study on characteristics of flow and thermal fields around rotating cylinder

10.30544/450 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 71-86
Author(s):  
Kamel Korib ◽  
Mohamed ROUDANE ◽  
Yacine Khelili
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Simple Algorithm ◽  
Rotation Rates ◽  
Rotating Circular Cylinder ◽  
Flow And Heat Transfer ◽  
Lift And Drag ◽  
Energy Equations ◽  
Volume Method

In this paper, a numerical simulation has been performed to study the fluid flow and heat transfer around a rotating circular cylinder over low Reynolds numbers. Here, the Reynolds number is 200, and the values of rotation rates (α) are varied within the range of 0 < α < 6. Two-dimensional and unsteady mass continuity, momentum, and energy equations have been discretized using the finite volume method. SIMPLE algorithm has been applied for solving the pressure linked equations. The effect of rotation rates (α) on fluid flow and heat transfer were investigated numerically. Also, time-averaged (lift and drag coefficients and Nusselt number) results were obtained and compared with the literature data. A good agreement was obtained for both the local and averaged values.

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