Mo Yang^a,*, Xiaoming Wang^a, Zhiyun Wang^a, Zheng Li^b , Yuwen Zhang^b

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-6, 2018, DOI:10.5098/hmt.11.7

Abstract Turbulent convective heat transfer in an elliptical pipe are investigated numerically in this paper. The RSM model is employed in the simulations of elliptical tubes with different aspect ratio a/b and Reynolds numbers within the range of 10,000~120,000. It is found that the maximum deviation between the numerical result and the one from Dittus-Boelter equation contained a hydraulic diameter is 28.4%. Based on simulation results, the correlation between the Nusselt number and Reynolds number in the fully developed fluid section of the elliptical tube is obtained. More >

Dongxiao Zhang¹, Lin Lu^1,*, Xiaobin Qi^2,3, Xuepu Yan¹, Cisong Gao¹, Yanxiao Hu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2707-2728, 2023, DOI:10.32604/fdmp.2023.028641

Abstract A two-dimensional model, employing a dynamic mesh technology, is used to simulate numerically the transient multiphase flow field produced by two submerged parallel guns. After a grid refinement study ensuring grid independence, five different conditions are considered to assess the evolution of cavitation occurring in proximity to the gun muzzle. The simulation results show that flow interference is enabled when the distance between the parallel barrels is relatively small; accordingly, the generation and evolution of the vapor cavity becomes more complex. By means of the Q criterion for vorticity detection, it is shown that cavitation causes the generation of vorticity… More >

Jiuxuan Liu, Yong Zeng^*, Xueya Zhao, Hongbo Chen, Bin Yan, Qian Lu

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2499-2518, 2023, DOI:10.32604/fdmp.2023.028413

Abstract

A method combining computational fluid dynamics (CFD) and an analytical approach is proposed to develop a prediction model for the variable thickness of the spray-induced liquid film along the surface of a cylindrical workpiece. The numerical method relies on an Eulerian-Eulerian technique. Different cylinder diameters and positions and inclinations of the spray gun are considered and useful correlations for the thickness of the liquid film and its distribution are determined using various data fitting algorithms. Finally, the reliability of the proposed method is verified by means of experimental tests where the robot posture is changed. The provided correlation are intended… More > Graphic Abstract

Weiting Jiang^1,*, Lei Zhao^1,*, Chongyang Wang², Tingni He¹, Weiguo Pan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2597-2611, 2023, DOI:10.32604/fdmp.2023.027504

Abstract When a brazed plate heat exchanger is used as an evaporator, the working mass in the channel may undergo solidification, thereby hindering the refrigeration cycle. In this study the liquid solidification process and its optimization in a brazed plate heat exchanger are investigated numerically for different inlet velocities; moreover, different levels of corrugation are considered. The results indicate that solidification first occurs around the contacts, followed by the area behind the contacts. It is also shown that dead flow zones exist in the sharp areas and such areas are prone to liquid solidification. After optimization, the solidification area attains its… More >

Fuyong Su^a,*, Rui Song^a , Peiwei Ni^a , Zhi Wen^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-5, 2019, DOI:10.5098/hmt.12.25

Abstract A mathematical model of the inverse heat transfer problem of blast furnace lining is established in this study. Following the identification of the boundary conditions of the model, the inverse problem via the conjugate gradient method was decomposed into three issues: the direct problem, the sensitivity problem, and the adjoint problem. The feasibility of the model was verified through two types of real inner wall boundary shape functions. The effects of the initial inner wall boundary shape function and the number of measuring points are also investigated. Results showed that the accuracy of the inverse solution is independent of the… More >

Qingxin Ba^a , Scott Egbert^b, Xuefang Li^a,* , Lin Cheng^a,**

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.20

Abstract Precalciner performance is crucial to the production rate and lifespan of cement kiln systems. The gas-solid flow and pulverized coal combustion processes in an industrial precalciner were numerically modeled to understand the flow patterns and thermal processes in the system. The gas and meal flow rates and properties were measured on-site to determine the boundary conditions for the simulations and to validate the models. The upward swirl of the gas flow in the furnace helped disperse the particles and extend their duration in the precalciner. The O₂ and CO₂ concentration distributions indicated that the coal particles were well dispersed and… More >

Weiyu Zhang^a , Mo Yang^a,*, Yuwen Zhang^b

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-8, 2019, DOI:10.5098/hmt.12.18

Abstract The periodically fully-developed flow and heat transfer in channels with periodic semi-circular tube is studied numerically by the direct numerical simulation (DNS), the large eddy simulation (LES), and the Reynolds stress model (RSM). When the Reynolds number is between 3000 and 25000, the Nusselt number obtained by the RSM is closer to the experimental results than the results obtained from other turbulence models. The nonlinear characteristics of flow and heat transfer is revealed based on the results of numerical simulation. When Reynolds number is high, the geometric structure and boundary conditions of the channel are symmetric, but the flow field… More >

Yubing Li^a , Mo Yang^a,*, Jian Li^b , Zhiyun Wang^a

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-8, 2019, DOI:10.5098/hmt.13.11

Abstract Thermalsolutal convection induced by mass and heat source in horizontal cavity is investigated numerically based on SIMPLE algorithm with QUICK scheme. The high-concentration heat source is placed in the square cavity, and the cavity wall is low temperature and low concentration. The smoke is used as the diffusion medium, and the flow field, temperature and concentration of the fluid under different Rayleigh number, buoyancy ratio Nc, Soret numbers and Dufour numbers are analyzed systematically. Parameter study demonstrates that heat and mass transfer of thermosolutal convection are enhanced with increasing Rayleigh number or buoyancy ratio, and the couple-diffusive interaction has a… More >

Ming Zhao^* , Yang Tian

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-10, 2019, DOI:10.5098/hmt.13.4

Abstract The field synergy principle and thermal resistance analysis were carried out for the heat transfer enhancement of a chip heat sink. Thermal analysis of the heat dissipation capacity is applied for setting up the gallery on the rib, changing the fan ventilation diameter, and changing the rib height. The results show that the analysis of field synergy principle agrees well with that of the thermal analysis, and setting up a gallery on the rib can improve the heat capacity of the heat sink. Meanwhile, the results also show that decreasing diameter of the ventilation causes heat capacity dropping because the… More >

Xuewen Cao^a,b,*, Qi Chu^a,b, Xiaodan Song^a,b, Yuxuan Li^a,b, Jiang Bian^a,b

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-9, 2019, DOI:10.5098/hmt.13.2

Abstract Wet natural gas widely exists in the natural gas industry, and the selection of throttling devices plays an important role in wet natural gas transportation. In order to study the flow field characteristics of different throttling devices in wet natural gas pipelines, a set of Laval nozzles, orifice plates, and plate valves have been designed. The standard k-ε model was selected for numerical simulation. By changing inlet pressure, inlet temperature or volume fraction of water-liquid, the pressure field and temperature fields of different throttling devices were obtained, and the influence of the presence of a shockwave on the flow fields… More >