Tin-Kan Hung^1,*, Ruei-Hung Kuo², Cheng-Hsien Chiang³

Molecular & Cellular Biomechanics, Vol.17, No.1, pp. 19-24, 2020, DOI:10.32604/mcb.2019.07817

Abstract Kinematic and dynamic characteristics of pulsating flow in a model of human aortic arch are obtained by a computational analysis. Three-dimensional flow processes are summarized by pressure distributions on the symmetric plane together with velocity and pressure contours on a few cross sections for systolic acceleration and deceleration. Without considering the effects of aortic tapering and the carotid arteries, the development of tubular boundary layer with centrifugal forces and pulsation are also analyzed for flow separation and backflow during systolic deceleration. More >

D. O. Redchyts¹, E. A. Shkvar^2,*, S. V. Moiseienko³

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.5, pp. 509-525, 2019, DOI:10.32604/fdmp.2019.08266

Abstract A mathematical model for unsteady electro- and aerodynamic processes in the presence of a plasma actuator has been elaborated through physical modeling of the dielectric barrier discharge. A specialized computational fluid dynamics package has been developed accordingly in order to calculate steady and unsteady laminar and turbulent flows. For the numerical simulation of the dielectric barrier discharge, in particular, two equations have been added to the Navier-Stokes equations and solved. They describe the distribution of the applied voltage and the charged particles density. The impact of the plasma actuator on air has been accounted for… More >

Zhaoli Tian^1,2, Yunlong Liu^1,2,*, Shiping Wang¹, A Man Zhang¹, Youwei Kang³

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.2, pp. 397-423, 2019, DOI:10.31614/cmes.2019.04419

Abstract The low frequency load of an underwater explosion bubble and the generated waves can cause significant rigid motion of a ship that threaten its stability. In order to study the fluid-structure interaction qualitatively, a two-dimensional underwater explosion bubble dynamics model, based on the potential flow theory, is established with a double-vortex model for the doubly connected bubble dynamics simulation, and the bubble shows similar dynamics to that in 3-dimensional domain. A fully nonlinear fluid-structure interaction model is established considering the rigid motion of the floating body using the mode-decomposition method. Convergence test of the model… More >

T. Chekifi^1,2,*, B. Dennai², R. Khelfaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.14, No.3, pp. 201-212, 2018, DOI:10.3970/fdmp.2018.00322

Abstract The fluidic oscillator is an interesting device developed for passive flow measurement. These microsystems can produce a high oscillating jet frequency with high flow velocity. The main advantages of fluidic oscillators are that no moving parts is included in the device. Commercial CFD code FLUENT was used to perform analysis of flows in fluidic oscillator. Numerical simulations were carried out for different flow conditions, where water and air were used as working fluids. The oscillation frequencies were identified by the discrete fast Fourier transform method (FFT). Furthermore a low-pressure vortex of fluid flow in the More >

O. K. Koriko, I. L. Animasaun^*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-13, 2017, DOI:10.5098/hmt.8.26

Abstract The motion of air (i.e fluid) in which tiny particle rotates past a pointed surface of a rocket (as in space science), over a bonnet of a car and past a pointed surface of an aircraft is of important to experts in all these fields. Geometrically, all the domains of fluid flow in all these cases can be referred to as the upper horizontal surface of a paraboloid of revolution (uhspr). Meanwhile, the solution of the corresponding partial differential equation is an open question due to unavailability of suitable similarity variable to non-dimensionalize the angular momentum… More >

Seyed Ehsan Rafiee^*, M. M. Sadeghiazad

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-15, 2016, DOI:10.5098/hmt.7.13

Abstract The aim of this investigation is study on separation phenomenon inside a special vortex tube affected by structural and physical factors including; throttle diameter, nozzle number and injection pressure as well as the parametric optimization based on separation efficiency using experimental and 3D-CFD methods. The results show that convergent VT with Dth=5.5mm provides 30.01% and 20.04% higher cooling and heating effectiveness compared to basic model. As another result, the higher injection pressure, the higher cooling effectiveness. The cooling effectiveness improves (16.86%) with increase in slot number up to N=4, then decreases. The maximum disagreement between More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-16, 2016, DOI:10.5098/hmt.7.22

Abstract The numerical investigations on flow structure, heat transfer characteristic and thermal performance in a circular tube heat exchanger with various shapes of winglet vortex generators are reported. The rectangular winglet vortex generators (RWVG), delta winglet vortex generators (DWVG) and curve winglet vortex generators (CWVG) are inserted in the middle of the test tube on both downstream and upstream arrangements. The effects of blockage ratios; BR = 0.1 – 0.3, with single pitch ratio (PR = 1) and flow attack angle (α = 30o) on thermal performance are studied for the Reynolds numbers; Re = 100 – 2000. The… More >

Divyprakash C. Pal, Abhik Majumder^*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-9, 2016, DOI:10.5098/hmt.7.1

Abstract In this present work heat transfer characteristics, thermal performance and pressure drop are studied numerically for a finned-tube bank heat exchanger with Delta Winglet Vortex Generator (DWVG) on the fin at different angle of attack (α). The thermo-fluid is studied by varying α at 15o , 25o , 30o and 35o . The base length (lDW) of the winglet also varied from 20mm to 35mm. The heat transfer coefficient and pressure drop increased in all the cases with increase in Reynolds number. However, significant increase in heat transfer of about 23.92% was observed for α More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-19, 2015, DOI:10.5098/hmt.6.13

Abstract Numerical investigations on flow topology, heat transfer behavior and thermal performance evaluation in a circular tube heat exchanger with the punched delta winglet vortex generators (PDWVG) inserted in the middle of the test section are presented. The effects of the flow attack angles that converging to the center of the tube; α = 0°, 5°, 10°, 15°, 20°, 25°, and flow directions; winglet tips pointing downstream and upstream, are investigated for the Reynolds numbers; Re = 100 – 2000. The finite volume method and SIMPLE algorithm are used for the current study. The results are presented… More >

S. Aggoune¹, C. Abid², E.H. Amara^1,3

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.2, pp. 115-125, 2015, DOI:10.3970/fdmp.2015.011.115

Abstract This paper focuses on the vortex formation effect during the application of a laser-fusion cutting technique. This industrial technique is typically associated with the ejection of a film of molten stainless steel blown off by a subsonic laminar jet of nitrogen gas used to assist the process. Without taking into account the transverse movement of the workpiece, we consider a 4 mm thick stainless steel plate. The resulting molten metal flow is assumed to be laminar, steady, viscous and incompressible. The numerical results reveal vortex structures adjacent to the walls at the entrance of the More >