scholarly journals Flow of a thin liquid-metal film in a toroidal magnetic field

2019 ◽  
Vol 867 ◽  
pp. 835-876 ◽  
Author(s):  
D. Lunz ◽  
P. D. Howell
Keyword(s):  
Magnetic Field ◽  
Free Surface ◽  
Liquid Metal ◽  
Surface Profile ◽  
Toroidal Magnetic Field ◽  
Leading Order ◽  
Governing Equations ◽  
Free Surface Profile ◽  
Gravity Driven ◽  
Gravity Driven Flow

We investigate the gravity-driven flow of a thin film of liquid metal on a conducting conical substrate in the presence of a strong toroidal magnetic field (transverse to the flow and parallel to the substrate). We solve the leading-order governing equations in a physically relevant asymptotic limit to find the free-surface profile. We find that the leading-order fluid flow rate is a non-monotonic bounded function of the film height, and this can lead to singularities in the free-surface profile. We perform a detailed stability analysis and identify values of the relevant geometric, hydrodynamic and magnetic parameters such that the flow is stable.

Two-dimensional natural element analysis of double-free surface flow under a radial gate

2012 ◽  
Vol 39 (6) ◽  
pp. 643-653 ◽  
Author(s):  
Farhang Daneshmand ◽  
S.A. Samad Javanmard ◽  
Jan F. Adamowski ◽  
Tahereh Liaghat ◽  
Mohammad Mohsen Moshksar
Keyword(s):  
Free Surface ◽  
Surface Profile ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Free Surface Profile ◽  
Natural Element ◽  
Gravity Driven ◽  
Radial Gate

The gravity-driven free surface flow problems for which both the solid and free surface boundaries are highly curved are very difficult to solve. A computational scheme using a variable domain and a fixed domain natural element method (NEM) is developed in the present study for the computation of the free surface profile, velocity and pressure distributions, and the flow rate of a 2D gravity fluid flow through a conduit and under a radial gate. The problem involves two highly curved unknown free surfaces and arbitrary curved-shaped boundaries. These features make the problem more complicated than flow under a sluice gate or over a weir. The fluid is assumed to be inviscid and incompressible and the results obtained are confirmed by conducting a hydraulic model test. The results are in agreement with other flow solutions for free surface profiles and pressure distributions.

scholarly journals Dam-Break Flows: Comparison between Flow-3D, MIKE 3 FM, and Analytical Solutions with Experimental Data

2018 ◽  
Vol 8 (12) ◽  
pp. 2456 ◽  
Author(s):  
Hui Hu ◽  
Jianfeng Zhang ◽  
Tao Li
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Analytical Solution ◽  
Water Depth ◽  
3D Model ◽  
Real Life ◽  
Surface Profile ◽  
Dam Break ◽  
Computational Time ◽  
Free Surface Profile

The objective of this study was to evaluate the applicability of a flow model with different numbers of spatial dimensions in a hydraulic features solution, with parameters such a free surface profile, water depth variations, and averaged velocity evolution in a dam-break under dry and wet bed conditions with different tailwater depths. Two similar three-dimensional (3D) hydrodynamic models (Flow-3D and MIKE 3 FM) were studied in a dam-break simulation by performing a comparison with published experimental data and the one-dimensional (1D) analytical solution. The results indicate that the Flow-3D model better captures the free surface profile of wavefronts for dry and wet beds than other methods. The MIKE 3 FM model also replicated the free surface profiles well, but it underestimated them during the initial stage under wet-bed conditions. However, it provided a better approach to the measurements over time. Measured and simulated water depth variations and velocity variations demonstrate that both of the 3D models predict the dam-break flow with a reasonable estimation and a root mean square error (RMSE) lower than 0.04, while the MIKE 3 FM had a small memory footprint and the computational time of this model was 24 times faster than that of the Flow-3D. Therefore, the MIKE 3 FM model is recommended for computations involving real-life dam-break problems in large domains, leaving the Flow-3D model for fine calculations in which knowledge of the 3D flow structure is required. The 1D analytical solution was only effective for the dam-break wave propagations along the initially dry bed, and its applicability was fairly limited.

scholarly journals Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1758
Author(s):  
Juan Macián-Pérez ◽  
Francisco Vallés-Morán ◽  
Santiago Sánchez-Gómez ◽  
Marco De-Rossi-Estrada ◽  
Rafael García-Bartual
Keyword(s):  
Free Surface ◽  
Energy Dissipation ◽  
Velocity Distribution ◽  
Physical Model ◽  
Hydraulic Jump ◽  
Surface Profile ◽  
Air Entrainment ◽  
Stilling Basin ◽  
Free Surface Profile ◽  
Stilling Basins

The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy dissipation purposes, which brings the importance of physical modeling into the spotlight. However, despite the importance of stilling basins in engineering, bibliographic studies have traditionally focused on the classical hydraulic jump. Therefore, the objective of this research was to study the characteristics of the hydraulic jump in a typified USBR II stilling basin, through a physical model. The free surface profile and the velocity distribution of the hydraulic jump developed within this structure were analyzed in the model. To this end, an experimental campaign was carried out, assessing the performance of both, innovative techniques such as the time-of-flight camera and traditional instrumentation like the Pitot tube. The results showed a satisfactory representation of the free surface profile and the velocity distribution, despite some discussed limitations. Furthermore, the instrumentation employed revealed the important influence of the energy dissipation devices on the flow properties. In particular, relevant differences were found for the hydraulic jump shape and the maximum velocity positions within the measured vertical profiles, when compared to classical hydraulic jumps.

Measurements of the time-varying free-surface profile across the swash zone obtained using an industrial LIDAR

2010 ◽  
Vol 57 (11-12) ◽  
pp. 1059-1065 ◽  
Author(s):  
C.E. Blenkinsopp ◽  
M.A. Mole ◽  
I.L. Turner ◽  
W.L. Peirson
Keyword(s):  
Free Surface ◽  
Surface Profile ◽  
Time Varying ◽  
Swash Zone ◽  
Free Surface Profile
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