The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Mary F. Wheeler - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of Hydraulic Jump
International Journal for Numerical Methods in Engineering, 1994Co-Authors: S. Chippada, B. Ramaswamy, Mary F. WheelerAbstract:Hydraulic Jump on a straight horizontal channel with supercritical Froude numbers 2·0 and 4·0 is numerically simulated by solving the Reynolds averaged Navier–Stokes equations. Turbulence is modelled through the k–ϵ closure equations and the mixed Eulerian–Lagrangian description of flow is utilized to overcome the problem posed by moving free boundary. Time stepping is done via fractional step method and pressure is determined from Poisson's equation. Galerkin finite element method with three-noded triangular elements is used for spatial discretization. A detailed study of the internal and external characteristics of Hydraulic Jump is done and compared with experimental values where possible. Surface roller and recirculation zone are found to play a dominant role in turbulence generation and dissipation.
S. Chippada - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of Hydraulic Jump
International Journal for Numerical Methods in Engineering, 1994Co-Authors: S. Chippada, B. Ramaswamy, Mary F. WheelerAbstract:Hydraulic Jump on a straight horizontal channel with supercritical Froude numbers 2·0 and 4·0 is numerically simulated by solving the Reynolds averaged Navier–Stokes equations. Turbulence is modelled through the k–ϵ closure equations and the mixed Eulerian–Lagrangian description of flow is utilized to overcome the problem posed by moving free boundary. Time stepping is done via fractional step method and pressure is determined from Poisson's equation. Galerkin finite element method with three-noded triangular elements is used for spatial discretization. A detailed study of the internal and external characteristics of Hydraulic Jump is done and compared with experimental values where possible. Surface roller and recirculation zone are found to play a dominant role in turbulence generation and dissipation.
Javad Farhoudi - One of the best experts on this subject based on the ideXlab platform.
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theoretical criterion for stability of free Hydraulic Jump on adverse stilling basins
Journal of Hydraulic Structures, 2014Co-Authors: Javad Farhoudi, Hossein Khalili ShayanAbstract:Hydraulic Jump on adverse stilling basin is an unstable phenomenon which causes some complexities in controlling of the Jump. This paper considers the stability of free Hydraulic Jump on adverse stilling basins from a theoretical point of view. A minimum value of upstream Froude number is needed to produce the free Hydraulic Jump on adverse stilling basins which was presented by a theoretical equation. Also, the effects of an end sill and divergence in section on the minimum Froude number were investigated. Moreover, it is required that the bed has a minimum friction for making the Jump stable which is obtained as a function of upstream Froude number and bed slope. This condition was compared with the criterion proposed by previous researchers and showed the considerable deviations at larger bed slopes. The result showed that it is impossible to establish the Hydraulic Jump on concrete adverse stilling basins without any appurtenances. However, diverging in section can improve the stability of Hydraulic Jump on adverse stilling basins.
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Submerged Hydraulic Jump with sediment-laden flow
International Journal of Sediment Research, 2012Co-Authors: Mohsen Nasrabadi, M H Omid, Javad FarhoudiAbstract:Abstract In this experimental study, the effect of suspended sediment concentration on the characteristics of a submerged Hydraulic Jump in a rectangular channel has been investigated, based on the sediment concentrations of 0.43%-16.15% and jet Froude numbers were in the range of 1.9-5. Two grain sizes, 0.15 and 0.03 mm ( ρ s =2.65 g/cm 3 ) have been used in the experiments. Characteristics of the submerged Hydraulic Jump including the submergence depth at the gate, length of submerged Hydraulic Jump, energy dissipation, velocity, and concentration distribution have been studied in both smooth and rough beds. Results showed that the submergence depth at the gate and the energy dissipation were constant regardless of sediment concentration. However, in the presence of suspended sediment, the length of the submerged Hydraulic Jump is smaller than that of clear water flow. It was also found that suspended sediment increase flow resistance, as a result of decreased in the maximum flow velocity.
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Force on Slab beneath Hydraulic Jump
Journal of Hydraulic Engineering, 1991Co-Authors: Javad Farhoudi, Rangaswami NarayananAbstract:Experiments have been carried out to measure the mean and fluctuating forces exerted on the slab beneath the free Hydraulic Jump. Slabs of various lengths and widths have been used at Froude numbers of the upstream flow varying from 4.0 to 10.0. The intensity of force fluctuations on an area of slab beneath a Hydraulic Jump depends on its length and width, and on its position from the toe of the Jump. Experimental results show that the transverse scale of pressure producing patterns of the turbulent Hydraulic Jump is longer than the streamwise scale. The scales of these patterns vary with the Froude number of the flow and the position within the Jump. The probability of the force fluctuations has been measured. The results with respect to large slabs are presented in a form that would help in estimating the intensity of force fluctuations. It is hoped that the results are useful to the designers of the stilling basin.
Sergey Gavrilyuk - One of the best experts on this subject based on the ideXlab platform.
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Structure of the Hydraulic Jump in convergent radial flows
Journal of Fluid Mechanics, 2019Co-Authors: Kseniya Ivanova, Sergey GavrilyukAbstract:We are interested in modelling of multidimensional turbulent Hydraulic Jumps in convergent radial flow. To describe the formation of intensive eddies near the free surface (rollers) at the front of the Hydraulic Jump, a new model of shear shallow water flows is used. The governing equations form a non–conservative hyperbolic system with dissipation source terms. The structure of equations is reminiscent of generic Reynolds-averaged Euler equations for barotropic compressible turbulent flows. Two types of dissipative terms are studied. The first one corresponds to Chézy-like dissipation rate, and the second one to a standard energy dissipation rate commonly used in compressible turbulence. Both of them guarantee the positive definiteness of the Reynolds stress tensor. The equations are rewritten in polar coordinates and numerically solved by using an original splitting procedure. Numerical results for both types of dissipation are presented and qualitatively compared with the experimental works. The results show both experimentally observed phenomena (cusp formation at the front of the Hydraulic Jump) as well as new flow patterns (the shape of the Hydraulic Jump becomes a rotating square).
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Structure of the Hydraulic Jump in convergent radial flows
Journal of Fluid Mechanics, 2019Co-Authors: Kseniya Ivanova, Sergey GavrilyukAbstract:We are interested in the modelling of multi-dimensional turbulent Hydraulic Jumps in convergent radial flow. To describe the formation of intensive eddies (rollers) at the front of the Hydraulic Jump, a new model of shear shallow water flows is used. The governing equations form a non-conservative hyperbolic system with dissipative source terms. The structure of equations is reminiscent of generic Reynolds-averaged Euler equations for barotropic compressible turbulent flows. Two types of dissipative term are studied. The first one corresponds to a Chézy-like dissipation rate, and the second one to a standard energy dissipation rate commonly used in compressible turbulence. Both of them guarantee the positive definiteness of the Reynolds stress tensor. The equations are rewritten in polar coordinates and numerically solved by using an original splitting procedure. Numerical results for both types of dissipation are presented and qualitatively compared with the experimental works. The results show both experimentally observed phenomena (cusp formation at the front of the Hydraulic Jump) as well as new flow patterns (the shape of the Hydraulic Jump becomes a rotating square).
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Structure of the Hydraulic Jump in convergent radial flows
Journal of Fluid Mechanics, 2018Co-Authors: Kseniya Ivanova, Sergey GavrilyukAbstract:We are interested in modelling of multidimensional turbulent Hydraulic Jumps in convergent radial flow. To describe the formation of intensive eddies near the free surface (rollers) at the front of the Hydraulic Jump, a new model of shear shallow water flows is used. The governing equations form a non–conservative hyperbolic system with dissipation source terms. The structure of equations is reminiscent of generic Reynolds-averaged Euler equations for barotropic compressible turbulent flows. Two types of dissipative terms are studied. The first one corresponds to Chezy-like dissipation rate, and the second one to a standard energy dissipation rate commonly used in compressible turbulence. Both of them guarantee the positive definiteness of the Reynolds stress tensor. The equations are rewritten in polar coordinates and numerically solved by using an original splitting procedure. Numerical results for both types of dissipation are presented and qualitatively compared with the experimental works. The results show both experimentally observed phenomena (cusp formation at the front of the Hydraulic Jump) as well as new flow patterns (the shape of the Hydraulic Jump becomes a rotating square).
B. Ramaswamy - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of Hydraulic Jump
International Journal for Numerical Methods in Engineering, 1994Co-Authors: S. Chippada, B. Ramaswamy, Mary F. WheelerAbstract:Hydraulic Jump on a straight horizontal channel with supercritical Froude numbers 2·0 and 4·0 is numerically simulated by solving the Reynolds averaged Navier–Stokes equations. Turbulence is modelled through the k–ϵ closure equations and the mixed Eulerian–Lagrangian description of flow is utilized to overcome the problem posed by moving free boundary. Time stepping is done via fractional step method and pressure is determined from Poisson's equation. Galerkin finite element method with three-noded triangular elements is used for spatial discretization. A detailed study of the internal and external characteristics of Hydraulic Jump is done and compared with experimental values where possible. Surface roller and recirculation zone are found to play a dominant role in turbulence generation and dissipation.
