Feng-Lin Zhou^a , Kai-Yuan Zhang ^a, Liang Cheng^b,† , Hai-Bing Cai^c, Yu-Liang Zhang^b, Min-Feng Lv^d

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-10, 2023, DOI:10.5098/hmt.20.22

Abstract In order to grasp the reverse startup characteristics of a small radial vane pump in the case of misoperation, a circulation piping system that includes the pump is established. Numerical simulation of the full three-dimensional unsteady incompressible viscous flow is performed based on the slip-grid technique and user-defined functions (UDF). According to the results, the static pressure fluctuation is small at the inlet of the centrifugal pump during the reverse startup, which differs significantly from the forward startup. Compared to the impeller rotational speed, the time required for the shaft power, head and flow curves… More >

Ghaith Yahya Abusaibaa^a , Kamaruzzaman Sopian^a,*, Hasila Jarimi^a , Adnan Ibrahim^a, Saffa Riffat^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-6, 2023, DOI:10.5098/hmt.20.21

Abstract This study will demonstrate the performance of a photovoltaic (PV) powered vapour compression cooling system connected to a Phase Change Material (PCM) storage tank. Three options were studied, namely (a) PV vapour compression with a PCM storage tank and an air-conditioned room with chilled water circulation with transparent membrane/desiccant; (b) PV vapour compression with a PCM storage tank and an air-conditioned room with chilled air dehumidification; and (c) PV vapour compression with a PCM storage tank and an air-conditioned room chilled by combined water circulation, a transparent membrane/desiccant, and air duct dehumidification. Simulation using TRNSYS,… More >

Qais Abid Yousif^a , Omar Rafae Alomar^a,*, Obed M. Ali^b , Omar Mohammed Ali^c

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-14, 2023, DOI:10.5098/hmt.20.20

Abstract This work involves a numerical investigation on free convection heat transfer occurred by a hot cylinder immersed in a square duct cooled from one side under different temperatures. Simulations have been done for a large ranges of Rayleigh number (10³ ≤ Ra ≤10⁷ ) and right wall temperature (0≤T_r ≤0.75). The results displayed that Nu is enhanced with rising in Ra and decreasing in T_r. The value of Nu is decreased with rising in T_r, where the maximum reduction in Nu is about 32% for T_r=0.75 as compared to T_r=0. The maximum enhancement range for Nu is found between 50% and 100% More >

Xuehui Jing^a,* , Wei Li^a, Zhaoyu Li^a , Zhiyun Wang^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-4, 2023, DOI:10.5098/hmt.20.19

Abstract This paper numerically simulates the combustion in a 300MW tangentially fired pulverized high-alkali coal boiler under low-load conditions. The combustion process, temperature distribution and the thermal load in the furnace at different height are analyzed under three different load conditions, which are 30%, 45% and 60% of full load. The temperature distribution and the variation of NO_x concentration under different load conditions are investigated, as well. The results show that the combustion processes of pulverized high-alkali coal in the furnace are similar under different load conditions, but the positions of the fuel’s full combustion are related… More >

Ameer Abed Jaddoa^* , Karema Assi Hamad, Arshad Abdul Jaleil Hameed

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.18

Abstract In the Heat Transfer process, many innovations were introduced aiming to obtain the most optimum behavior of the cooling process using nanofluids as coolant liquids. These nanofluids have gained much attention in cooling systems due to their special rheological and thermal performance. In this work, an experimental evaluation is conducted for nanofluids Al₂O₃, SiO₂, CuO, ZnO, and TiO₂ nanoparticles applied to a mini-channel. The nanofluid particles were entirely spread out in purified water (size of 15 nm) before being passed to the heat sink through a confined inflow channel. The obtained results showed that the achieved improvement… More >

Hussein Al-Gburi^*, Akeel Abbas Mohammed, Audai Hussein Al-Abbas

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.17

Abstract Transferring thermal energy efficiently necessitates utilizing a heat exchanger capable of producing the full thermal power of the energy supply at lowest possible cost and time. Therefore, in the present investigation, the impact of corrugated helical coil concentric tube-in-tube heat exchanger on the thermal performance is investigated experimentally. As a continuous in our issue of heat exchanger, the corrugated helical tube-in-tube is carried out and compared with smooth helical tube-in-tube for free convection heat transfer. The set-up of the experimental apparatus are designed and utilized to be appropriate for the cooling and heating systems of… 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… More >

Wenhua Liu^a,b, Mo Yang^c,a,*, Yuwen Zhang^b , Guiliang Liu^a , Liang Ling^a , Xuchen Ying^a,*

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.15

Abstract In this study, numerical investigations are performed on a partially premixed flame of methane and air in two- and three-dimensional models. Nonlinear method is adopted to illustrate the asymmetric phenomenon that affects the flame stability under various co-flow velocities. According to the results, the mathematical relationship between the flame flickering frequency Stanton number and the dimensionless velocity Froude number has been summarized as St=0.7Fr^-0.46. The bifurcation phenomena under different Reynold numbers are found to have significant influence on the system stability. Two critical bifurcation points, which is when Re=300 and Re=1200, are determined as the onset More >

Linfang Fang, Fuyong Su^* , Zhen Kang, Haojun Zhu

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.14

Abstract Taking the ladle used by a factory as an example, a three-dimensional finite element model of the ladle was established, and the temperature distribution law of the lining during the ladle transportation was studied using the finite element analysis software ANSYS, which verified the good thermal insulation performance of the nano thermal insulation layer, and analyzed and compared the temperature and distribution law of the refractory lining under the two working conditions of the heavy ladle and the empty ladle. The results show that due to the change of the boundary conditions in the empty More >

Qi Zhuang^a,* , Dong Liu^b, Bo Liu^c, Mei Liu^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-6, 2023, DOI:10.5098/hmt.20.13

Abstract In the actual operation of wet gas pipeline, liquid accumulation is easy to form in the low-lying and uphill sections of the pipeline, which leads to a series of problems such as reduced pipeline transportation efficiency, increased pipeline pressure drop, hydrate formation, slug flow and intensified corrosion in the pipeline. Accurate calculation of liquid holdup is of great significance to the research of flow pattern identification, pipeline corrosion evaluation and prediction, and gas pipeline transportation efficiency calculation. Based on the experimental data of liquid holdup in horizontal pipeline, a commonly used BP neural network (BPNN)… More >