P. R. Sharma^a , Sushila Choudhary^a,* , O. D. Makinde^b

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-7, 2017, DOI:10.5098/hmt.9.18

Abstract Steady two dimensional laminar magnetohydrodynamic (MHD) slip flow and heat transfer of a viscous incompressible and electrically conducting fluid past over a flat exponentially non-conducting stretching porous sheet embedded in a porous medium with non uniform permeability in the presence of non uniform heat source is investigated. The governing equations of velocity and temperature distributions are solved numerically and the effects of different physical parameters are shown through graphs. The rate of shear stress and the rate of heat transfer at the sheet are derived, discussed numerically and their numerical values for various values of physical parameters are presented through… More >

A. Subba Rao^a,* , V. Ramachandra Prasad^a , P. Rajendra^a , M. Sasikala^a , O. Anwar Beg^b

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-9, 2017, DOI:10.5098/hmt.9.2

Abstract In this article, we investigate the nonlinear steady state boundary layer flow and heat transfer of an incompressible Jeffery non-Newtonian fluid from a permeable horizontal isothermal cylinder. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a versatile, implicit, finite-difference technique. The numerical code is validated with previous studies. The influence of a number of emerging non-dimensional parameters, namely with Deborah number (De), surface suction parameter (S), Prandtl number (Pr), ratio of relaxation to retardation times (λ) and dimensionless tangential coordinate (ξ) on velocity and temperature evolution in the boundary layer regime are examined in… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-19, 2018, DOI:10.5098/hmt.10.6

Abstract Convective heat transfer, pressure loss and thermal performance in a heat exchanger tube inserted with the modified V-shaped baffle are investigated numerically. The influences of the flow attack angle (α = 20o , 30o and 45o ), baffle height in term of blockage ratio (b/D = BR = 0.05, 0.10, 0.15, 0.20 and 0.25) and arrangement (The V-tip pointing downstream is called “V-Downstream”, while the V-tip pointing upstream is named “V-Upstream”.) on heat transfer and friction loss are presented for the Reynolds number in range 100 – 1200 (laminar region). The numerical study (finite volume method) is selected to solve… More >

Yashwant Singh^a , Rajesh Maithani^b , Sunil Kumar^a , Ehsan Gholamalizadeh^c , Anil Kumar^a,d,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-16, 2018, DOI:10.5098/hmt.11.33

Abstract Nanofluids play important roles in the heat transfer and flow characteristics in ribbed square channels. Systematic experiments are conducted to measure heat transfer enhancement and TiO₂-H₂O based nanofluid flow characteristics on a protruded with combined V-type ribbed square channel. Reynolds number studied in the channel range from 4000-18000. Investigational parameters of square channel contain, volume fraction range of 1.0- 4.0%, particle diameter range of 30nm-45nm, relative protruded rib height range of 0.10-0.25, ratio of protruded height to print diameter range of 0.8- 2.0, relative protruded rib pitch ratio range of 2.0-3.5 and angle of attack of 300 -750 respectively. Results… More >

Ralph Eismann^a,† , Robert Adams^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-7, 2018, DOI:10.5098/hmt.11.4

Abstract Convergence of numerical schemes for pipe network analysis requires continuous modelling of pressure losses in the transition region between laminar and turbulent regions. Several existing correlations for the friction factor of straight pipes and helical tubes are presented. Based on these correlations a new explicit correlation for helical tubes with arbitrary surface roughness is derived. The friction factor is expressed as a continuous function of the Reynolds number covering laminar, transitional, and turbulent flow regions. Potential sources of error are also discussed, including the effects of tube deformation caused by the bending process. More >

Xin Wang^1,3, Ying Yan^1,3, Hongmei Ji^1,3,*, Xiaowu Li^1,2,*

Journal of Renewable Materials, Vol.11, No.8, pp. 3297-3308, 2023, DOI:10.32604/jrm.2023.027066

Abstract As an essential renewable mineral resource, mollusk shells can be used as handicrafts, building materials, adsorbents, etc. However, there are few reports on the wear resistance of their structures. The Vicker’s hardness and friction, and wear resistance of different microstructures in mollusk shells were comparatively studied in the present work. The hardness of prismatic structures is lower than that of cross-lamellar and nacreous structures. However, the experimental results of sliding tests indicate that the prismatic structure exhibits the best anti-wear ability compared with foliated, crossed-lamellar, and nacreous structures. The anti-wear and hardness do not present a positive correlation, as the… More > Graphic Abstract

Firas Aziz Ali^a,*, Adnan M. Alsaffawi^b , Karam Hashim Mohammed^a

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-7, 2020, DOI:10.5098/hmt.15.21

Abstract The augmentation of the heat transfer in heat exchangers is one of the methods to increase efficiency of the system. The double tube heat exchanger is selected to many suitable techniques of heat transfer enhancement. In this study; the friction factor and heat transfer coefficient of double tube is evaluated experimentally. The Al₂O₃ nanoparticles dispersed in ethylene glycol (EG) with a diameter 50 nm and the weight concentration (0.1%, 0.3%, 0.5%, 0.7%, 1%) has been utilized. Then the effect of parallel current and counter current with different ranges of Reynolds number (10,000 to 30,000) on the friction factor and heat… More >

O. M. Oyewola^a,b,* , M. O. Petinrin^a , and H. O. Sanusi^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.16

Abstract The flow and heat transfer behaviour of channels with dimples and protrusions of spherical and piriform shapes was numerically explored by solving the Navier-Stokes and energy equations with a CFD software, the ANSYS Fluent 19.3, in the range of Reynolds numbers from 8,500 to 59,000. The values of the Nusselt number and friction factors were estimated and the non-dimensional Performance Evaluation Criterion (PEC) was determined to measure the thermal-hydraulic performance. The results reveal that the piriform protruded channel demonstrated a higher thermal performance with Nusselt number values of 36%, 15%, 23%, and 9% than the smooth, spherical dimpled, piriform dimpled,… More >

R. Selvam^1,*, L. Ganesh Babu², Joji Thomas³, R. Prakash¹, T. Karthikeyan¹, T. Maridurai⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 569-577, 2023, DOI:10.32604/fdmp.2022.022187

Abstract Hybrid materials collected from organic and inorganic sources, which are traditionally used as brake lining materials, generally include fly ash, cashew shell powder, phenolic resins, aluminium wool, barites, lime powder, carbon powder and copper powder. The present research focuses on the specific effects produced by fly ash and aims to provide useful indications for the replacement of asbestos due to the health hazards caused by the related fibers. Furthermore, the financial implications related to the use of large-volume use of fly ash, lime stone and cashew shell powder, readily available in most countries in the world, are also discussed. It… More > Graphic Abstract

Shrikant Arunrao Thote^*, Netra Pal Singh

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 711-722, 2023, DOI:10.32604/fdmp.2022.021651

Abstract The thermo-hydraulic properties of circular tubes with a twisted tape inside (used accordingly to induce turbulence and enhance heat transfer through the tube wall) are described for Reynolds Numbers ranging from 830 to 1990. Tapes twisted with the three distinct twist ratios are considered, namely, 6, 4.4 and 3. Air is used as the working fluid in several tests. For the sake of comparison, the standard tube with no insert is also examined. It is shown that in the presence of the twisted tape, the ‘frictional factor’, ‘Nusselt Number’ and the ‘thermal performance factor’ are much higher than those obtained… More >