Zhijie Huang^1,2,3, Zuyu Chen^1,2,3, Xiaodan Ren^4,*, Jing Hu³, Xuedong Zhang³, Lu Hai⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 139-155, 2019, DOI:10.31614/cmes.2019.04596

Abstract Damage and threats to hydraulic and submarine structures by underwater explosions (UNDEXs) have raised much attention. The centrifuge model test, compared to prototype test, is a more promising way to examine the problem while reducing cost and satisfying the similitude requirements of both Mach and Froude numbers simultaneously. This study used a systematic approach employing centrifuge model tests and numerical simulations to investigate the effects of UNDEXs on an air-backed steel plate. Nineteen methodical centrifuge tests of UNDEXs were conducted. The shock wave pressure, bubble oscillation pressure, acceleration and the strain of the air-backed steel More >

Cherfi Ryad^1,*, Sadaoui Djamel¹, Sahi Adel¹, Mouloud Smail¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.2, pp. 153-169, 2019, DOI:10.32604/fdmp.2019.04294

Abstract The present work relates to a numerical investigation of double diffusive mixed convection around a horizontal annulus with a finned inner cylinder. The solutal and thermal buoyancy forces are sustained by maintaining the inner and outer cylinders at uniform temperatures and concentrations. Buoyancy effects are also considered, with the Boussinesq approximation. The forced convection effect is induced by the outer cylinder rotating with an angular velocity (ω) in an anti-clockwise direction. The studies are made for various combinations of dimensionless numbers; buoyancy ratio number (N), Lewis number (Le), Richardson number (Ri) and Grashof number (Gr). More >

Jun Du^1,*, Xin Wu¹, Ruonan Li¹, Ranran Cheng¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 77-87, 2019, DOI:10.32604/fdmp.2019.05949

Abstract In this paper, we take the mid-temperature gravity heat pipe exchanger as the research object, simulate the fluid flow field, temperature field and the working state of heat pipe in the heat exchanger by Fluent software. The effects of different operating parameters and fin parameters on the heat transfer performance of heat exchangers are studied. The results show that the heat transfer performance of the mid-temperature gravity heat pipe exchanger is the best when the fin spacing is between 5 mm and 6 mm, the height of the heat pipe is between 12 mm and More >

Geniy V. Kuznetsov, Alexander E. Nee^*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-9, 2018, DOI:10.5098/hmt.10.26

Abstract This study deals with the numerical investigation of combined heat transfer via conduction, laminar natural convection, and surface radiation in a closed rectangular cavity with a radiant heating source. Unsteady two-dimensional equations of mass, momentum, and energy conservation for complex heat transfer process under study were formulated in terms of the vorticity – stream function – temperature variables and solved by means of the finite difference method on a uniform grid. Developed numerical code was validated against two benchmark problems of convective and convective-radiative heat transfer. When analyzing complex heat transfer regularities, we varied the… More >

CH. Amanulla^a,b,*, N. Nagendra^b , M. Suryanarayana Reddy^c

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-13, 2018, DOI:10.5098/hmt.10.10

Abstract The present study deals with the computational analysis on an electrically conducting magneto viscoelastic fluid over a circular cylinder. Prescribed partial slip effects are also taken into account. The governing physical problem is tackled numerically by using the highly efficient and reliable Keller box algorithm. Impact of sundry physical parameters on physical quantities of interest are evaluated. The influence of Williamson viscoelastic fluid parameter, magnetic body force parameter, Thermal and velocity (hydrodynamic) slip parameters, stream wise variable and Prandtl number on thermos-fluid characteristics are studied graphically. The model is relevant to the simulation of magnetic More >

Yun Whan Na^* , J. N. Chung^†

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-14, 2018, DOI:10.5098/hmt.11.36

Abstract Flow instabilities of convective two-phase boiling in a trapezoidal microchannel were investigated. using a three-dimensional numerical model. Parameters such as wall temperature and inlet pressure that characterize the instability phenomena of flow boiling with periodic flow patterns were studied at different channel wall heat fluxes and flow mass fluxes. Results were obtained for various wall heat flux levels and mass flow rates. The numerical results showed that large amplitude and short period oscillations for wall temperature and inlet pressure fluctuations are major characteristics of flow instability. The wall temperature fluctuations are mainly initiated by the More >

Mohammed A. Tashkandi^a , Abdelkarim Aydi^b,*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-6, 2018, DOI:10.5098/hmt.11.27

Abstract In this work, a computational study of convective heat transfer in a hybrid CNT-Al2O3/water nanofluid cavity filled. The main considered parameters are the Rayleigh number and nanoparticles volume fraction. Results are presented in terms of flow structure, temperature field, and average Nusselt number. Since CNT and Al₂O₃ have different shapes to models are used to evaluate the effective thermal conductivity. It was found that both increasing Rayleigh number and nanoparticles volume fraction increase the heat transfer intensify the flow and affect the temperature field. Adding nanoparticles enhances the heat transfer due to the enhancement of the More >

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 >

Peixian Li^1,*, Zhixiang Tan², Lili Yan³

CMES-Computer Modeling in Engineering & Sciences, Vol.117, No.2, pp. 231-250, 2018, DOI:10.31614/cmes.2018.02573

Abstract In order to prolong the life cycle of the coal mine, Jinggezhuang (‘JGZ’) coal mine decided to excavate the shaft pillar. The first panel 0091 was designed near the pillar boundary as an experiment in shaft pillar mining. Both probability integral method (PIM) and FLAC^3D were used to evaluate the influence on the shaft safety. PIM parameters were obtained from previous surface subsidence station. The rock property is based on the lab mechanical test. A simulated FLAC^3D model containing shafts and a panel was built based on stratigraphic information. Surface subsidence results of PIM show that… More >

Haojun Peng^1,*, Ping Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.114, No.1, pp. 59-73, 2018, DOI:10.3970/cmes.2018.114.059

Abstract In this paper, a three dimension model is built according to real surface cleaner in airport runway rubber mark cleaning vehicle and numerical simulation of this model is carried out using Ansys Fluent software. After comparison and analysis the flow field between high speed rotating waterjet and static waterjet formerly studied by other researchers, the influences of different standoff distance from nozzle outlet to runway surface and rotation speed on rubber mark cleaning effect is simulated and analyzed. Results show the optimal operation parameters for the simulated model and quantitative advices are given for design, More >