Xiaojia Wang^1,*, Danyang Shao¹, Delu Chen¹, Yutong Gong¹, Fengxia An^1,2

Journal of Renewable Materials, Vol.11, No.7, pp. 3155-3175, 2023, DOI:10.32604/jrm.2023.027535

Abstract Organic solid waste (OSW) contains many renewable materials. The pyrolysis and gasification of OSW can realize resource utilization, and its products can be used for methanation reaction to produce synthetic natural gas in the specific reactor. In order to understand the dynamic characteristics of the reactor, a three-dimensional numerical model has been established by the method of Computational Fluid Dynamics (CFD). Along the height of the reactor, the particle distribution in the bed becomes thinner and the mean solid volume fraction decreases from 4.18% to 0.37%. Meanwhile, the pressure fluctuation range decreased from 398.76 Pa at the entrance to a… More > Graphic Abstract

Lohit Sharma^a , Sunil Kumar^a , Robin Thakur^a , Bhaskar Goel^a , Amar Raj Singh Suri^a , Sashank Thapa^a , Nitin Kumar^a , Rajesh Maithani^b , Anil Kumar^b

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-15, 2020, DOI:10.5098/hmt.14.30

Abstract This article presents an extensive review on exergy analysis of nanofluid flow through heat exchanger channels. The improvement of exergy efficiency of nanofluid flow through heat exchanger are determined by the net impact of the relative variations in the thermophysical properties of the nanoparticle which are sensitive towards numerous parameters including size and shape, material and concentration as well as base fluid thermal properties. Exergy efficiency of nanofluids flowing through heat exchanger is greater as compare to simple conventional fluids. The augmentation of exergy efficiency in the nanofluid flow through heat exchangers can be achieved by breaking laminar sub layer… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-11, 2020, DOI:10.5098/hmt.14.27

Abstract Numerical predictions on heat transfer characteristic, flow topology and thermal performance assessment in a square duct are presented. The passive technique, insertion of the vortex generator, is opted to develop the heat transfer rate in the square duct heat exchanger. The vortex generator of the present research is Double V-Orifice (DVO). The square duct equipped with DVO is tested with various parameters. The influences of DVO height, b, to the duct height, H, or b/H, gap spacing between the outer edge of the orifice and the duct wall, s, to the duct height or s/H and flow directions (tip-pointing-Downstream and… More >

Zhipeng Tang^a, Yongbin Zhang^b,*

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-5, 2020, DOI:10.5098/hmt.14.26

Abstract The critical flow rate through a micro/nano slit pore for starting the adsorbed layer-fluid or adsorbed layer-wall interfacial slippage is calculated by a multiscale scheme. There are the physical adsorbed layers on the channel walls and the intermediate continuum fluid which are respectively in noncontinuum and continuum flows. The flow factor approach model for nanoscale flow is used to simulate the adsorbed layer flow, and a continuum model describes the continuum fluid flow. The boundary between the adsorbed layer and the continuum fluid or the boundary between the adsorbed layer and the channel wall are treated as the interfacial slippage.… More >

Changming Ling^a,b,*, Yin Zhong^a,b

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-6, 2020, DOI:10.5098/hmt.14.25

Abstract Effects of serrated pulsating airflow on liquid film evaporation in a falling film channel was numerically studied based on a two-dimensional model. The mechanism of pulsating airflow evaporation was studied as the pulsating airflow swept across the vertical liquid film surface at the stagnant temperature. Effects of amplitude, frequency, and velocity of the serrated pulsating airflow at certain evaporation time on evaporation were analyzed. Compared with the uniform airflow, the highest relative evaporation of liquid film on vertical pipe inner surface was increased by about 0.3 %. When the airflow was pulsating, the cycle of vapor mass flow rate was… More >

Obed Y.W. Abotsi, John P. Kizito^*

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-6, 2020, DOI:10.5098/hmt.14.24

Abstract In this paper, turbulent water flow and heat transfer are studied numerically in a pipe which is rotating about its longitudinal axis. Computations were conducted for axial Reynolds numbers ranging from 10000 to 30000 at different rotation rates. Rotation rate (N) is the ratio of the rotational Reynolds number to the axial Reynolds number. Predictions showed that the Nusselt number (Nu) of the stationary pipe (N=0) was augmented by 50-58% at N=5, 105-132% at N=10, 150-201% at N=15, 208-265% at N=20, and 320-373% at N=30. Improvements in the heat transfer rate was linked to the introduction of tangential velocity components… More >

Andriyanto Setyawan^a,*

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-6, 2020, DOI:10.5098/hmt.14.22

Abstract In this paper, the effect of evaporating temperature on the void fraction and flow pattern of R290 in an evaporator of air conditioning unit has been studied. The analysis was carried out for evaporator diameter of 7.9 mm and 6.3 mm and cooling capacity of 2.64 kW and 5.28 kW. The analysis was conducted at evaporating temperature of -20°C to +5°C with an increment of 5°C. At the inlet of evaporator, the void fraction ranges from 0.932 to 0.984, whereas at the outlet the void fraction is 1. Testing the void fraction by using 3 available correlations gives the good… More >

Ali Rehman^a , Zabidin Salleh^a,* , Taza Gul^b

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-7, 2020, DOI:10.5098/hmt.14.20

Abstract This research paper explains the analytical solution unsteady squeezing flow of water based CNTs for both MWCNT and SWCNT in the presence of magnetic field and variable thermal conductivity. The given partial differential equation is converted to nonlinear ordinary differential equation by using the similarity transformation and solve by analytical method namely optimal homotopy asymptotic method (OHAM) to obtain analytical solution of the nonlinear problem which analyze the problem. The result of important parameter for both velocity and temperature profiles are plotted and discussed. The BVPh 2.0 package is used to obtain the convergence of the problem up to 25… More >

Stanford Shateyi^a,∗, Hillary Muzara^b

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-10, 2020, DOI:10.5098/hmt.14.18

Abstract A theoretical analysis has been carried out to investigate the influence of unsteadiness on the laminar two-phase magnetohydrodynamic nanofluid flow filled with porous medium under the combined effects of Brownian motion and thermophoresis. Thermal variable conductivity, thermal radiation and viscous dissipation effects are also considered in this numerical study. The highly nonlinear partial differential equations are transformed into a set of coupled nonlinear ordinary differential equations through suitable similarity transformations. The resultant ordinary differential equations are then numerically solved using the spectral quasilinearization method. The effects of the pertinent physical parameters over the fluid velocity, temperature, concentration, skin friction, Nusselt… More >

Hamzeh T. Alkasasbeh^a,*, Mohammed Z. Swalmeh^b , Hebah G. Bani Saeed^c , Feras M. Al Faqih^c , Adeeb G. Talafha^c

Frontiers in Heat and Mass Transfer, Vol.14, No.1, pp. 1-7, 2020, DOI:10.5098/hmt.14.15

Abstract This study aims at considering the properties of heat transfer and magneto-hydrodynamics (MHD) Casson nanofluid at the existence of free convection boundary layer flow with Carbon Nanotubes (CNTs) suspended in human blood/water as based fluid on a stretching sheet. Two types of CNTs nanoparticles, single walled carbon nanotubes (SWCNTs) and multi walled carbon nanotubes (MWCNTs), are taken into account. The governing partial differential equations are transformed to partial differential equations using similar transformation, then solved numerically by an implicit finite difference scheme known as Keller-box method (KBM). The results for physical quantities, the local skin friction, and local Nusselt number,… More >