Convective Boundary Conditions Effect on Cylindrical Media with Transient Heat Transfer

Lattice Boltzmann method is used to solve inside a cylindrical cavity with convective boundary condition is highlighted in this paper. Because of its simple, stable, accurate, efficient and ease for parallelization, we use the thermal Single Relaxation Time Bhatnagar Gross Krook (SRT BGK) mesoscopic approach in order to solve the energy equation. Thermal fields are simulated using D2Q9 scheme. We introduce and demonstrate numerically some usual cases (Dirichlet, Newmann) of Boundary conditions (Bcs). After validation, we extend the present work to the convective case. At the wall of the cavity, the unknown Thermal Distribution Functions (TDF) are exposed to the bounce back concept which is determined consistently by one of the imposed BCs. An in-house Fortran 90 code is used to analyze a variety of BCs inside a two-dimensional cavity. In validation, obtained results highlight a good agreement with literature. The present study is extended to deal with convective boundary condition for conduction transfer problems inside an axisymmetric cylindrical media subjected to heat generation and Newman boundary conditions.

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Mixed Convection Flow of Viscoelastic Fluid over a Sphere under Convective Boundary Condition Embedded in Porous Medium

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.362.67 ◽

2015 ◽

Vol 362 ◽

pp. 67-75 ◽

Cited By ~ 3

Author(s):

A.R.M. Kasim ◽

L.Y. Jiann ◽

N.A. Rawi ◽

A. Ali ◽

S. Shafie

Keyword(s):

Boundary Layer ◽

Boundary Condition ◽

Porous Medium ◽

Boundary Conditions ◽

Mixed Convection ◽

Viscoelastic Fluid ◽

Convective Boundary Condition ◽

Convection Flow ◽

Convective Boundary ◽

Viscoelastic Parameter

The investigation on mixed convection boundary layer of a viscoelastic fluid over a sphere which is embedded in porous medium under convective boundary condition is carried out in this paper. The boundary layer equations of viscoelastic fluid are an order higher than Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. Hence, the augmentation on extra boundary conditions is needed in order to solve this problem. The governing partial differential equations are first transformed into non-dimensional forms and then solved numerically using the Keller-box method by augmenting extra boundary conditions at infinity. The numerical results obtained for limiting case are comparing with related outcomes in order to validate the present results. Results on the effects of the viscoelastic parameter in the presence of porosity and mixed convection on the skin friction and heat transfer as well as velocity and temperature profile have been discussed.

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Impact of surface temperature and convective boundary conditions on a Nanofluid flow over a radially stretched Riga plate

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/09544089211054407 ◽

2021 ◽

pp. 095440892110544

Author(s):

K.V. Prasad ◽

Hanumesh Vaidya ◽

Fateh Mebarek-Oudina ◽

Rajashekhar Choudhari ◽

Kottakkaran Sooppy Nisar ◽

...

Keyword(s):

Boundary Condition ◽

Boundary Conditions ◽

Surface Temperature ◽

Surface Concentration ◽

Mass Transfer Process ◽

Convective Boundary Condition ◽

Convective Boundary Conditions ◽

Convective Boundary ◽

Analytical Methodology ◽

Riga Plate

The current work provides the optimal homotopic analytical methodology for the steady circulation over a non-isothermal radially stretched Riga plate/disc unit. The attributes of the heat, along with the mass transfer process, are assessed in the existence of variable transport and magnetic features. Radial stretched Riga disc is considered along with additional realistic boundary heating conditions, namely, prescribed surface temperature as well as prescribed surface concentration, convective boundary conditions and also zero mass flux concentration on the surface area of the Riga disc. The model tracks Brownian motion as well as the thermal diffusion of nanoparticles in fluid circulation all at once. Regulating equations, which are highly coupled, are changed right into non-dimensional equations using appropriate transformations of similarity. Through assembling series solutions, the resulting framework is planned and examined. Graphic summaries are offered for the rheological qualities of various parameters in size for velocity, temperature, as well as nanoparticles. The modified Hartman number improves the velocity distribution and reduces the temperature distribution in both prescribed surface temperature and convective boundary condition cases. The effect of the chemical reaction parameter shows the reduced concentration distribution for the prescribed surface temperature case. In contrast, it is precisely the opposite in the convective boundary condition case.

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Comparison of 1-D vs 3-D Combustion Boundary Conditions for SI Engine Thermal Load Prediction

Volume 2: Fuels; Numerical Simulation; Engine Design, Lubrication, and Applications ◽

10.1115/icef2013-19227 ◽

2013 ◽

Cited By ~ 3

Author(s):

O. Iqbal ◽

S. Jonnalagedda ◽

K. Arora ◽

L. Zhong ◽

S. Gaikwad

Keyword(s):

Heat Transfer ◽

Boundary Condition ◽

Temperature Distribution ◽

Boundary Conditions ◽

Cylinder Head ◽

Convective Boundary Condition ◽

Combustion Model ◽

Convective Boundary Conditions ◽

Convective Boundary ◽

Simulation Code

The thermal field generated in an engine block and cylinder head as a result of combustion loading is of paramount significance for structural durability. Computational fluid dynamics and heat transfer modeling provide strong tools; perhaps the best and most precise available for predicting thermal fields within cylinder head and engine block. However, an enduring challenge has been the temperature prediction on metal wall as a response to the time dependent fluctuations in the fluids. Fluid (coolant) flow in an engine is steady for a given engine speed and load, but combustion dynamics are inherently transient. In this study, an effective set of convective boundary condition data (as combustion load) is generated using two different approaches in a stand-alone simulation and mapped onto a decoupled Conjugate Heat Transfer (CHT) model to predict the temperature distribution in the engine. In the first approach, a predictive combustion model, tuned to dyno test data, is solved in a 1-D simulation code. This provides the cycle-averaged convective boundary condition that can be used for a CHT model as a uniform heat source. In the second, more detailed approach, in-cylinder combustion simulations involving transient piston and valve motion with flame propagation modeling are carried out using a 3-D simulation code. The 3-D methodology gives a detailed distribution of convective boundary conditions on the walls touching the combustion gases. In order to predict the gradients in heat transfer coefficient with high accuracy, the resulting temperature distribution from the CHT simulation is fed back into the combustion model to regenerate the set of convective boundary conditions. This process is repeated until a converged set of convective boundary conditions are obtained. In this paper engine temperature predictions obtained using combustion loads from both 1-D and 3-D approaches will be compared with the thermocouple data from engine dyno test.

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