Heather Dillon^a , Ashley Emery^b,† , Ann Mescher^b

Frontiers in Heat and Mass Transfer, Vol.4, No.2, pp. 1-9, 2013, DOI:10.5098/hmt.v4.2.3004

Abstract A computational model is presented that extends prior work on unsteady natural convection in a tall rectangular cavity with aspect ratio 10 and applies Proper Orthogonal Decomposition to the results. The solution to the weakly compressible Navier-Stokes equation is computed for a range of Rayleigh numbers between 2 × 10⁷ and 2.2 × 10⁸ with Prandtl number 0.71. A detailed spectral analysis shows dynamic system behavior beyond the Hopf bifurcation that was not previously observed. The wider Rayleigh range reveals new dynamic system behavior for the rectangular geometry, specifically a return to a stable oscillatory behavior that was not predicted… More >

Tapas Ray Mahapatra^a, Sumanta Sidui^b, Samir Kumar Nandy^c,*

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-15, 2014, DOI:10.5098/hmt.5.15

Abstract The effect of variable transverse magnetic field on steady two-dimensional indirect natural convection flow of an incompressible viscous fluid over a horizontal hot flat plate is theoretically studied. The governing partial differential equations are transformed into ordinary ones by similarity transformation and solved numerically using fourth order Runge-Kutta method with shooting technique. The results are obtained for the skin friction coefficient and the local Nusselt number as well as the dimensionless velocities, temperature for some values of the magnetic parameter (M) subject to either prescribed (constant or variable) surface temperature or prescribed (variable) heat flux. It is seen that the… More >

Manoj Kr. Triveni^* , Dipak Sen, RajSekhar Panua

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-8, 2014, DOI:10.5098/hmt.5.12

Abstract A numerical investigation has been performed for heat transfer analysis in a right-angled triangular enclosure filled with water. The side wall of the enclosure is maintained at high temperature compare to the base wall while hypotenuse is kept thermally insulated. Two - dimensional steady-state continuity, momentum and energy equations along with the boussinesq approximation are solved by finite volume method using commercial available software, FLUENT 6.3. The computational results are shown in terms of isotherms, streamlines and velocity contour for Rayleigh number (10⁵ ≤ Ra ≤ 10⁷ ). The heat transfer is presented in terms of local and average Nusselt… More >

Machireddy Gnaneswara Reddy^*

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-9, 2014, DOI:10.5098/hmt.5.4

Abstract The numerical solution of transient natural convection MHD flow past a vertical cylinder embedded in a porous medium with surface temperature and concentration along with thermal radiation is presented. The temperature and concentration level at the cylinder surface are assumed to vary as power law type functions, with exponents m and n respectively in the stream wise co-ordinate. The governing boundary layer equations are converted into a non-dimensional form. A Crank-Nicolson type of implicit finite-difference method is used to solve the governing non-linear set of equations. Numerical results are obtained and presented with various thermal and mass Grashof numbers and… More >

D. Srinivasacharya^a,*, A.J. Chamkha^b, O. Surender^a, A.M. Rashad^c,d

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-7, 2015, DOI:10.5098/hmt.6.19

Abstract The aim of the present article is to analyze the influence of thermal and mass stratification on natural convection heat and mass transfer over a porous vertical plate with uniform and constant wall temperature and concentration in porous medium. The Brinkman-Forchheimer based model is employed to describe the flow in the porous medium. The nonlinear governing equations and their associated boundary conditions are initially cast into dimensionless forms by pseudo-similarity variables. The resulting system of nonlinear, coupled partial differential equations is then solved numerically. The influence of pertinent parameters on the dimensionless velocity, temperature, concentration, heat and mass transfer coefficients… More >

Noureddine Abouricha^1,*, Chouaib Ennawaoui^1,2, Mustapha El Alami³

Frontiers in Heat and Mass Transfer, Vol.21, pp. 523-537, 2023, DOI:10.32604/fhmt.2023.045914

Abstract This work presents a simulation of the phenomena of natural convection in an enclosure with a variable heating regime by the lattice Boltzmann method (LBM). We consider a square enclosure of side H filled with air (Pr = 0.71) and heated from below, with a hot portion of length L = 0.8 H, by imposing a sinusoidal temperature. The unheated segments of the bottom wall are treated as adiabatic, and one of the vertical walls features a cold region, while the remaining walls remain adiabatic. The outcomes of the two-dimensional (2D) problem are depicted through isotherms, streamlines, the temperature evolution… More >

Manoj Kr. Triveni^*, Dipak Sen, RajSekhar Panua

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-6, 2015, DOI:10.5098/hmt.6.2

Abstract A numerical investigation through laminar natural convection has been executed to illuminate the effect of curvature ratio in an arch enclosure filled with water. The left side wall of the cavity is maintained at a higher temperature than that of the right side wall while the other walls are kept insulated. The governing equations such as continuity, momentum and energy equation are solved by finite volume method. The effect of pertinent parameters such as curvature ratio (1≤ CR ≤ 1.5) and Rayleigh number (1×10⁴ ≤ Ra ≤ 1×10⁶) and) on heat transfer are calculated by commercial available computational fluid dynamics… More >

Seyed Milad Mirabedin^*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-6, 2016, DOI:10.5098/hmt.7.17

Abstract This work focuses on numerical validation of natural convection heat transfer of TiO2-water nanofluids in a cylindrical container using COMSOL. The main aim of this study is to examine different available approaches to calculate effective thermal conductivity and compare them with experimental data available in the literature. Simulation results show that for considered mixture, average Nusselt number decreases by increasing Rayleigh number and particle volume fraction. It has been found that only one model was able to represent similar trends for given particle volume fractions, compared to experimental results. More >

Kun Zhang^*, Liang Bi Wang

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-7, 2016, DOI:10.5098/hmt.7.18

Abstract Detailed numerical analysis is presented for the effect of spaceship orbital transfer on solution convection during protein crystal growth under microgravity. The results show that the flow and mass transfer during protein crystal growth are unsteady in the process of orbital transfer. For the case of quasi-steady acceleration, the flow is so weak that the effect of flow on concentration field can be negligible. For the case of position adjustment, the convection is enhanced with protein crystal diameter d_c > 0.2 mm and slightly alters the purely diffusive concentration distribution under zero gravity condition. For the case of motor working,… More >

J. K. Singh^a,*, N. Joshi^a , S. G. Begum^a, C. T. Srinivasa^b

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-12, 2016, DOI:10.5098/hmt.7.24

Abstract In the present analytical study, we have considered unsteady hydromagnetic heat and mass transfer natural convection flow of an electrically conducting, heat absorbing and chemically reacting fluid past an exponentially accelerated vertical plate in a uniform porous medium taking Hall current and rotation into account. The species concentration near the plate is considered to be varies linearly with time. Two particular cases for plate temperature are considered i.e. (i) plate temperature is uniform and (ii) plate temperature varies linearly with time and after some time it is maintained at uniform temperature. The coupled partial differential equations governing the fluid flow… More >