Andrei Vasiliev, Andrei Sukhanovskii^*, Elena Popova

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 739-748, 2024, DOI:10.32604/fdmp.2024.048092

Abstract The formation of convective flows in a rotating cylindrical layer with an inclined bottom and free surface is studied. Convection is driven by localized cooling at the center of the upper free surface and by rim heating at the bottom near the sidewall. The horizontal temperature difference in a rotating layer leads to the formation of a convective flow with a complex structure. The mean meridional circulation, consisting of three cells, provides a strongly non-uniform differential rotation. As a result of the instability of the main cyclonic zonal flow, the train of baroclinic waves appears in the upper layer. The… More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.8, pp. 1-8, 2017, DOI:10.5098/hmt.8.35

Abstract Numerical investigations on flow and heat transfer characteristics in a circular tube heat exchanger inserted with right triangular wavy surfaces are reported. The configurations of the wavy surfaces; incline and V-shape, are studied with flow attack angles of 30o, 45o and 60o for the Reynolds numbers, Re = 100 – 2000. The numerical results are compared with the smooth circular tube. The mechanisms on flow and heat transfer in the tube heat exchanger with the wavy surface are presented. As the results, the wavy surface can generate the vortex flow and impinging flow through the test section that helps to… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-13, 2019, DOI:10.5098/hmt.12.19

Abstract The variations of flow and heat transfer in the square channel heat exchanger inserted with various parameters of V-orifice are investigated numerically. The influences of flow directions (V-Downstream and V-Upstream), gap spacing ratios (g/H or GR = 0, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) and blockage ratios (b/H or BR = 0.05, 0.10, 0.15, 0.25 and 0.30) on flow topology and heat transfer behavior are reported. The laminar flow regime with the Reynolds number in the range 100 – 2000 is considered. The numerical results are presented in terms of flow and heat transfer structure in the heat exchanger… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.14, 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 >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-13, 2022, DOI:10.5098/hmt.19.26

Abstract CFD analyses of flow characteristics and heat transfer topology in a heat exchanger duct (HXD) placed with three various configurations of the double V-baffles (DVB) are reported. Parameters of interest are DVB height ratios (b/H = 0.05 – 0.25), gap spacing ratios (g = 0.05 – 0.40), flow directions (+x, -x), and DVB configurations (Type I, II and III). Laminar flow with Reynolds numbers (based on the inlet conditions) between 100 – 2000 is measured. The present problem is solved with the finite volume method (a commercial program). Fluid flow and heat transfer characteristics in the tested duct are described.… More >

Aliasghar Azma¹, Ramin Kiyanfar², Yakun Liu^1,*, Masoumeh Azma^3,*, Di Zhang¹, Ze Cao¹, Zhuoyue Li¹

CMC-Computers, Materials & Continua, Vol.75, No.1, pp. 1711-1733, 2023, DOI:10.32604/cmc.2023.036680

Abstract Various regions are becoming increasingly vulnerable to the increased frequency of floods due to the recent changes in climate and precipitation patterns throughout the world. As a result, specific infrastructures, notably bridges, would experience significant flooding for which they were not intended and would be submerged. The flow field and shear stress distribution around tandem bridge piers under pressurized flow conditions for various bridge deck widths are examined using a series of three-dimensional (3D) simulations. It is indicated that scenarios with a deck width to pier diameter (Ld/p) ratio of 3 experience the highest levels of turbulent disturbance. In addition,… More >

Shuxian Gao¹, Yonggang Cao^2,*, Yuchuan Bai³, Yanhua Yang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 487-500, 2023, DOI:10.32604/fdmp.2022.021149

Abstract River bending is the major effect responsible for bed topography and bank changes. In this study, fluid velocity (measured by a three-dimensional Doppler advanced point current meter) and bed topographical data have been collected in 40 sections of an experimental model. The whole flume was composed of an organic glass bend, upstream and downstream water tanks, two transition straight sections, a circulation pump, and a connection pipeline. Each section has been found to be characterized by a primary circulation and a small reverse circulation, with some sections even presenting three more or more circulation structures. The minimum circulation intensity has… More >

Mohamed Omri^1,*, Yusuf Al-Turki², Ahmed A. Alghamdi¹, Amrid Amnache³, Luc G. Fréchette³

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 961-977, 2022, DOI:10.32604/cmc.2022.021406

Abstract In this paper, three-dimensional flows in laminar subsonic cascades at relatively low Reynolds numbers (Re < 2500) are presented, based on numerical calculations. The stator and rotor blade designs are those for a MEMS-based Rankine microturbine power-plant-on-a-chip with 109-micron chord blades. Blade passage calculations in 3D were done for different Reynolds numbers, tip clearances (from 0 to 20%) and incidences (0° to 15°) to determine the impact of aerodynamic conditions on the flow patterns. These conditions are applied to a blade passage for a stationary outer casing. The 3D blade passage without tip clearance indicates the presence of two large… More >

A.A. Ivanova¹, V.G. Kozlov^1,2,3, D.A. Polezhaev¹, D. Pareau³, M. Stambouli³

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.3, pp. 211-220, 2008, DOI:10.3970/fdmp.2008.004.211

Abstract The problem for the optimization of mass-transfer on the interface of two immiscible liquids by means of vibrational hydromechanics is studied experimentally. A new vibrational cell of Lewis's type expressly conceived for such purposes is described. Flow is generated by activators in the form of disks inducing translational axial oscillations near the opposite end faces of the cavity. It is shown that such vibrating disks can lead to the onset of a large-scale toroidal whirlwind effectively mixing the liquid throughout the volume. According to the experiments, in particular, axisymmetrical radial flows are generated on both sides of the horizontal liquid… More >

S. Hamimid¹, M. Guellal¹, A. Amroune¹, N. Zeraibi²

FDMP-Fluid Dynamics & Materials Processing, Vol.8, No.1, pp. 69-90, 2012, DOI:10.3970/fdmp.2011.008.069

Abstract A two-dimensional rectangular enclosure containing a binary-fluid saturated porous layer of finite thickness placed in the centre of the cavity is considered. Phase change is neglected. Vertical and horizontal solid boundaries are assumed to be isothermal and adiabatic, respectively. A horizontal temperature gradient is imposed, driving convection of buoyancy nature. The Darcy equation, including Brinkman and Forchheimer terms is used to account for viscous and inertia effects in the momentum equation, respectively. The problem is then solved numerically in the framework of a Velocity-Pressure formulation resorting to a finite volume method based on the standard SIMPLER algorithm. The effects of… More >