International Journal of Numerical Methods for Heat & Fluid Flow 

About: International Journal of Numerical Methods for Heat & Fluid Flow is an academic journal published by Emerald Publishing Limited. The journal publishes majorly in the area(s): Heat transfer & Nusselt number. It has an ISSN identifier of 0961-5539. Over the lifetime, 2682 publications have been published receiving 41118 citations. The journal is also known as: International journal of numerical methods for heat and fluid flow & Heat & fluid flow.

Heat transfer enhancement in turbulent tube flow using Al2O3 nanoparticle suspension

Abstract: Purpose – To study the hydrodynamic and thermal behaviors of a turbulent flow of nanofluids, which are composed of saturated water and Al2O3 nanoparticles at various concentrations, flowing inside a tube submitted to a uniform wall heat flux boundary condition.Design/methodology/approach – A numerical method based on the “control‐volume” approach was used to solve the system of non‐linear and coupled governing equations. The classical κ‐e model was employed in order to model the turbulence, together with staggered non‐uniform grid system. The computer model, satisfactorily validated, was used to perform an extended parametric study covering wide ranges of the governing parameters. Information regarding the hydrodynamic and thermal behaviors of nanofluid flow are presented.Findings – Numerical results show that the inclusion of nanoparticles into the base fluid has produced an augmentation of the heat transfer coefficient, which has been found to increase appreciably with an increase of particles volume co...

Natural convection in enclosures with localized heating from below and symmetrical cooling from sides

Abstract: Natural convection of air in a two‐dimensional, rectangular enclosure with localized heating from below and symmetrical cooling from the sides has been numerically investigated Localized heating is simulated by a centrally located heat source on the bottom wall, and four different values of the dimensionless heat source length, 1/5, 2/5, 3/5 and 4/5 are considered Solutions are obtained for Rayleigh number values from 103 to 106 Local results are presented in the form of streamline and isotherm plots as well as the variation of local Nusselt number on the heated wall Finally, the average Nusselt number at the heated part of the lower wall, \overline Nu, was shown to increase with an increase the Rayleigh number, Ra, or of the nondimensional heat source thickness, e

A study of natural convection heat transfer in a nanofluid filled enclosure with elliptic inner cylinder

Abstract: – The purpose of this paper is to study the effects of natural convection heat transfer in a cold outer circular enclosure containing a hot inner elliptic circular cylinder. The fluid in the enclosure is Cu-water nanofluid. The main emphasis is to find the numerical treatment for the said mathematical model. The effects of Rayleigh number, inclined angle of elliptic inner cylinder, effective of thermal conductivity and viscosity of nanofluid, volume fraction of nanoparticles on the flow and heat transfer characteristics have been examined. , – A very effective and higher order numerical scheme Control Volume-based Finite Element Method (CVFEM) is used to solve the resulting coupled equations. The numerical investigation is carried out for different governing parameters namely; the Rayleigh number, nanoparticle volume fraction and inclined angle of elliptic inner cylinder. The effective thermal conductivity and viscosity of nanofluid are calculated using the Maxwell-Garnetts (MG) and Brinkman models, respectively. , – The results reveal that Nusselt number increases with an increase of nanoparticle volume fraction, Rayleigh numbers and inclination angle. Also it can be found that increasing Rayleigh number leads to a decrease in heat transfer enhancement. For high Rayleigh number the minimum heat transfer enhancement ratio occurs at. , – To the best of the authors’ knowledge, no such analysis is available in the literature which can describe the natural convection heat transfer in a nanofluid filled enclosure with elliptic inner cylinder by means of CVFEM.

Short communication radiation effects on MHD free convection flow of a gas past a semi—infinite vertical plate

Abstract: Free convection heat transfer due to the simultaneous action of buoyancy, radiation and transverse magnetic field is investigated for a semi‐infinite vertical plate Solutions are derived by expanding the stream function and the temperature into a series in terms of the parameter ζ = x1/2 L–1/2, where L is the length of the plate Velocity and temperature functions are shown on graphs and the numerical values of functions affecting the shear stress and the rate of heat transfer are entered in a table The effects of the magnetic field parameter λ and the radiation parameter F on these functions are discussed

Analysis and Optimization of the Thermal Performance of Microchannel Heat Sinks

Abstract: – To provide modeling approaches of increasing levels of complexity for the analysis of convective heat transfer in microchannels which offer adequate descriptions of the thermal performance, while allowing easier manipulation of microchannel geometries for the purpose of design optimization of microchannel heat sinks., – A detailed computational fluid dynamics model is first used to obtain baseline results against which five approximate analytical approaches are compared. These approaches include a 1D resistance model, a fin approach, two fin‐liquid coupled models, and a porous medium approach. A modified thermal boundary condition is proposed to correctly characterize the heat flux distribution., – The results obtained demonstrate that the models developed offer sufficiently accurate predictions for practical designs, while at the same time being quite straightforward to use., – The analysis is based on a single microchannel, while in a practical microchannel heat sink, multiple channels are employed in parallel. Therefore, the optimization should take into account the impact of inlet/outlet headers. Also, a prescribed pumping power may be used as the design constraint, instead of pressure head., – Very useful design methodologies for practical design of microchannel heat sinks., – Closed‐form solutions from five analytical models are derived in a format that can be easily implemented in optimization procedures for minimizing the thermal resistance of microchannel heat sinks.