Latifa M. Al-Balushi, M. M. Rahman^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 441-463, 2020, DOI:10.32604/fdmp.2020.08551

Abstract In the present paper, the effect of the heat flux distribution on the natural convective flow inside a square cavity in the presence of a sloping magnetic field and magnetic nanoparticles is explored numerically. The nondimensional governing equations are solved in the framework of a finite element method implemented using the Galerkin approach. The role played by numerous model parameters in influencing the emerging thermal and concentration fields is examined; among them are: the location of the heat source and its lengthH*, the magnitude of the thermal Rayleigh number, the nanoparticles shape and volume fraction, and the Hartmann number. It… More >

Suvash C. Saha^1,*, Ali M. Sefidan², Atta Sojoudi³

Energy Engineering, Vol.117, No.1, pp. 1-17, 2020, DOI:10.32604/EE.2020.010418

Abstract Free convection inside an attic enclosure in which sinusoidal heat flux applied on the inclined walls and a constant temperature applied on the base wall has been investigated numerically to demonstrate the primary flow characteristics and heat transfer within the attic enclosure over daily routine cycles. To solve the governing equations, the finite volume technique has been utilized. After performing the grid independency and time step size tests, the roles of Rayleigh number (Ra) and the attic aspect ratio (AR) on the unsteady flow structure and heat transfer phenomenon are explained for a constant Prandtl number (0.72) for the air.… More >

S.N. Lee¹, S.W. Baek¹, K.M. Kim², M.J. Yu³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.1, pp. 1-8, 2010, DOI:10.3970/icces.2010.015.001

Abstract A finite volume method with nongray gases is applied to examine the radiative base heating due to plume which is changed by mechanical deflection. Numerical approaches are made to predict the effect of TVC. The radiative properties within plume flow are modeled with the weighted sum of 4 gray gases. The exhaust plume is considered as an absorbing and emitting medium with no scattering. Flow field is molded with using Preconditioned Navier-Stokes(N-S) algorithms with multi-block. The Geometric Conservation Law(GCL) is considered to compute the nozzle moving mechanism. The radiative base heating is changed by the nozzle deflection angle. More >

M.R. Myers¹, A.B. Jorge², D.E. Yuhas³, D.G. Walker¹

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.3, pp. 221-248, 2012, DOI:10.3970/cmes.2012.083.221

Abstract An adaptive extended Kalman filter is developed and investigated for a transient heat transfer problem in which a high heat flux spot source is applied on one side of a thin plate and ultrasonic pulse time of flight is measured between spatially separated transducers on the opposite side of the plate. The novel approach is based on the uncertainty in the state model covariance and leverages trends in the extended Kalman filter covariance to drive changes to the state model covariance during convergence. This work is an integral part of an effort to develop a system capable of locating the… More >

N. Osawa¹, K. Hashimoto¹, J. Sawamura¹, J. Kikuchi², Y. Deguchi², T. Yamaura²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 43-54, 2007, DOI:10.3970/cmes.2007.020.043

Abstract A new hypothesis regarding heat transmission during line heating is proposed. It states that the distribution of the temperature of the gas adjacent to the plate, T_G, and the overall local heat transfer coefficient, α, depend only on the distance from the torch. An identification technique for T_G and α is developed. The validity of the employed hypothesis and the proposed technique is demonstrated by comparing the measured and identified T_G during a spot heating test. The plate temperature calculated by direct heat conduction analysis closely approximates the one measured for the spot and line heating tests, when T_G and… More >

L. Belarche^1,2, B. Abourida¹, S. Smolen³

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 157-170, 2015, DOI:10.3970/fdmp.2015.011.157

Abstract Natural convection in a cubical cavity, discretely heated is studied numerically using a three-dimensional finite volume formulation. Two heating square portions are placed on the vertical wall of the enclosure, while the rest of the considered wall is adiabatic. The opposite vertical wall is maintained at a cold uniform temperature and the other walls are adiabatic. Effects of the heating sections dimensions ε (0.15 ≤ ε ≤ 0.35) and the Rayleigh number Ra (10³ ≤ Ra ≤ 10⁷) on the fluid flow and the heat transfer within the cavity are studied. The obtained results show that the flow intensity and… More >

Zhiqiang Yang¹, Yufeng Nie², Yatao Wu², Zihao Yang², Yi Sun¹

CMC-Computers, Materials & Continua, Vol.43, No.1, pp. 21-48, 2014, DOI:10.3970/cmc.2014.043.021

Abstract This paper develops a novel statistical second-order two-scale (SSOTS) method to predict the heat transfer performances of three-dimensional (3D) porous materials with random distribution. Firstly, the mesoscopic configuration for the structure with random distribution is briefly characterized Secondly, the SSOTS formulas for calculating effective thermal conductivity parameters, temperature field and heat flux densities are derived by means of construction way. Then, the algorithm procedure based on the SSOTS method is described in details. Finally, numerical results for porous materials with varying probability distribution models are calculated by SSOTS algorithm, and compared with the data by finite element method (FEM) in… More >

Chien-Ching Ma^1,2, Yi-Tzu Chen²

CMC-Computers, Materials & Continua, Vol.36, No.2, pp. 177-201, 2013, DOI:10.3970/cmc.2013.036.177

Abstract Functionally graded material (FGM) is a particulate composite with continuously changing its thermal and mechanical properties in order to raise the bonding strength in the discrete composite made from different phases of material constituents. Furthermore, FGM is a potent tool to create an intermediate layer in metal–ceramic composites to avoid the properties discontinuities and reduce, thereby, the residual stresses. For the nonhomogeneous problem, the mathematical derivation is much complicated than the homogeneous case since the material properties vary with coordinate. To analyze the problem, the Fourier transform is applied and the general solution in transform domain is obtained. The inverse… More >

Silieti, M.¹, Divo, E.², Kassab, A.J.¹

CMC-Computers, Materials & Continua, Vol.12, No.2, pp. 121-144, 2009, DOI:10.3970/cmc.2009.012.121

Abstract A hybrid singularity superposition/boundary element-based inverse problem method for the reconstruction of multi-dimensional heat flux distributions is developed. Cauchy conditions are imposed at exposed surfaces that are readily reached for measurements while convective boundary conditions are unknown at surfaces that are not amenable to measurements such as the walls of the cooling holes. The purpose of the inverse analysis is to determine the heat flux distribution along cooling hole surfaces. This is accomplished in an iterative process by distributing a set of singularities (sinks) inside the physical boundaries of the cooling hole (usually along cooling hole centerline) with a given… More >