The Experts below are selected from a list of 167163 Experts worldwide ranked by ideXlab platform
T Sahoo - One of the best experts on this subject based on the ideXlab platform.
-
surface gravity Wave Interaction with a submerged horizontal flexible porous plate
Applied Ocean Research, 2018Co-Authors: S C Mohapatra, T Sahoo, Guedes C SoaresAbstract:Abstract An analytical study for surface gravity Wave Interaction with submerged flexible porous plate based on small amplitude water Wave theory and structural response is presented. The flexible porous plate is modeled based on the thin elastic plate theory and Wave past porous plate is using generalized Darcy's law to incorporate both frictional force and inertia force. The dispersion relation is analyzed to determine the Wave motion characteristics of two propagating Wave modes in the presence of free surface and flexural Waves at the submerged horizontal porous plate in specific cases. Further, the linearized long Wave equation under shallow water approximation is derived in a direct manner and the limiting cases are compared. The integral forms of Green’s functions are derived using the fundamental solution associated with the two-dimensional Laplace equation. Using Green’s identity, the generalized expansion formulae for the Wave-maker problem associated with the surface Wave Interaction with the submerged flexible porous plate are obtained in both the cases of finite and infinite water depths. The usefulness of the expansion formula is demonstrated by analyzing a physical problem associated with the surface gravity Wave Interaction with a moored finite submerged horizontal elastic porous plate in finite water depth. In the numerical results, the accuracy of the numerical computations are checked and the combined effect of mooring stiffness and porous-effect parameter are analyzed on the reflection coefficients, Wave energy dissipation coefficients, and vertical forces. It is observed that the Wave energy dissipation/absorption depends significantly on the mooring stiffness, porous-effect parameter, and suitable positing of the submerged plate.
-
hydroelastic analysis of gravity Wave Interaction with submerged horizontal flexible porous plate
Journal of Fluids and Structures, 2015Co-Authors: H Behera, T SahooAbstract:The present study deals with the surface gravity Wave Interaction with submerged horizontal flexible porous plate under the assumption of small amplitude water Wave theory and structural response. The flexible porous plate is modeled using the thin plate theory and Wave past porous structure is based on the generalized porous Wavemaker theory. The Wave characteristics due to the Interaction of gravity Waves with submerged flexible porous structure are studied by analyzing the complex dispersion relation using contour plots. Three different problems such as (i) Wave scattering by a submerged flexible porous plate, (ii) Wave trapping by submerged flexible porous plate placed at a finite distance from a rigid wall and (iii) Wave reflection by a rigid wall in the presence of a submerged flexible porous plate are analyzed. The role of flexible porous plate in attenuating Wave height and creating a tranquility zone is studied by analyzing the reflection, transmission and dissipation coefficients for various Wave and structural parameters such as angle of incidence, depth of submergence, plate length, compression force and structural flexibility. In the case of Wave trapping, the optimum distance between the porous plate and rigid wall for Wave reflection is analyzed in different cases. In addition, effects of various physical parameters on free surface elevation, plate deflection, Wave load on the plate and rigid wall are studied. The present approach can be extended to deal with acoustic Wave Interaction with flexible porous plates.
-
gravity Wave Interaction with porous structures in two layer fluid
Journal of Engineering Mathematics, 2014Co-Authors: H Behera, T SahooAbstract:Oblique Wave Interaction with rectangular porous structures of various configurations in two-layer fluid are analyzed in finite water depth. Wave characteristics within the porous structure are analyzed based on plane Wave approximation. Oblique Wave scattering by a porous structure of finite width and Wave trapping by a porous structure near a wall are studied under small amplitude Wave theory. The effectiveness of three types of porous structures—a semi-infinite porous structure, a finite porous structure backed by a rigid wall, and a porous structure with perforated front and rigid back walls—in reflecting and dissipating Wave energy are analyzed. The reflection and transmission coefficients for Waves in surface and internal modes and the hydrodynamic forces on porous structures of the aforementioned configurations are computed for various physical parameters in two-layer fluid. The eigenfunction expansion method is used to deal with Waves past the porous structure in two-layer fluid assuming the associated eigenvalues are distinct. An alternate procedure based on the Green’s function technique is highlighted to deal with cases where the roots of the dispersion relation in the porous medium coalesce. Long Wave equations are derived and the dispersion relation is compared with that derived based on small amplitude Wave theory. The present study will be of significant importance in the design of various types of coastal structures used in the marine environment for the reflection and dissipation of Wave energy.
-
hydroelastic analysis of surface Wave Interaction with concentric porous and flexible cylinder systems
Journal of Fluids and Structures, 2013Co-Authors: S Mandal, Nabanita S Datta, T SahooAbstract:Abstract The present study deals with the hydroelastic analysis of gravity Wave Interaction with concentric porous and flexible cylinder systems, in which the inner cylinder is rigid and the outer cylinder is porous and flexible. The problems are analyzed in finite water depth under the assumption of small amplitude water Wave theory and structural response. The cylinder configurations in the present study are namely (a) surface-piercing truncated cylinders, (b) bottom-touching truncated cylinders and (c) complete submerged cylinders extended from free surface to bottom. As special cases of the concentric cylinder system, Wave diffraction by (i) porous flexible cylinder and (ii) flexible floating cage with rigid bottom are analyzed. The scattering potentials are evaluated using Fourier–Bessel series expansion method and the least square approximation method. The convergence of the double series is tested numerically to determine the number of terms in the Fourier–Bessel series expansion. The effects of porosity and flexibility of the outer cylinder, in attenuating the hydrodynamic forces and dynamic overturning moments, are analyzed for various cylinder configurations and Wave characteristics. A parametric study with respect to Wave frequency, ratios of inner-to-outer cylinder radii, annular spacing between the two cylinders and porosities is done. In order to understand the flow distribution around the cylinders, contour plots are provided. The findings of the present study are likely to be of immense help in the design of various types of marine structures which can withstand the Wave loads of varied nature in the marine environment. The theory can be easily extended to deal with a large class of problems associated with acoustic Wave Interaction with flexible porous structures.
S Gunter - One of the best experts on this subject based on the ideXlab platform.
-
double resonant fast particle Wave Interaction
Nuclear Fusion, 2012Co-Authors: M Schneller, Ph Lauber, M Brudgam, S D Pinches, S GunterAbstract:In future fusion devices fast particles must be well confined in order to transfer their energy to the background plasma. Magnetohydrodynamic instabilities like toroidal Alfv?n eigenmodes or core-localized modes such as beta-induced Alfv?n eigenmodes and reversed shear Alfv?n eigenmodes, both driven by fast particles, can lead to significant losses. This is observed in many ASDEX Upgrade discharges. This study applies the drift-kinetic HAGIS code with the aim of understanding the underlying resonance mechanisms, especially in the presence of multiple modes with different frequencies. Of particular interest is the resonant Interaction of particles simultaneously with two different modes, referred to as ?double-resonance?. Various mode overlapping scenarios with different q profiles are considered. It is found that, depending on the radial mode distance, double-resonance is able to enhance growth rates as well as mode amplitudes significantly. Surprisingly, no radial mode overlap is necessary for this effect. Quite the contrary is found: small radial mode distances can lead to strong nonlinear mode stabilization of a linearly dominant mode.
-
double resonant fast particle Wave Interaction
arXiv: Plasma Physics, 2012Co-Authors: M Schneller, Ph Lauber, M Brudgam, S D Pinches, S GunterAbstract:In future fusion devices fast particles must be well confined in order to transfer their energy to the background plasma. Magnetohydrodynamic instabilities like Toroidal Alfv\'en Eigenmodes or core-localized modes such as Beta Induced Alfv\'en Eigenmodes and Reversed Shear Alfv\'en Eigenmodes, both driven by fast particles, can lead to significant losses. This is observed in many ASDEX Upgrade discharges. The present study applies the drift-kinetic HAGIS code with the aim of understanding the underlying resonance mechanisms, especially in the presence of multiple modes with different frequencies. Of particular interest is the resonant Interaction of particles simultaneously with two different modes, referred to as 'double-resonance'. Various mode overlapping scenarios with different q profiles are considered. It is found that, depending on the radial mode distance, double-resonance is able to enhance growth rates as well as mode amplitudes significantly. Surprisingly, no radial mode overlap is necessary for this effect. Quite the contrary is found: small radial mode distances can lead to strong nonlinear mode stabilization of a linearly dominant mode.
Junchao Chen - One of the best experts on this subject based on the ideXlab platform.
-
residual symmetries and soliton cnoidal Wave Interaction solutions for the negative order korteweg de vries equation
Applied Mathematics Letters, 2017Co-Authors: Junchao Chen, Shundong ZhuAbstract:Abstract The residual symmetry is derived for the negative-order Korteweg–de Vries equation from the truncated Painleve expansion. This nonlocal symmetry is transformed into the Lie point symmetry and the finite symmetry transformation is presented. The multiple residual symmetries are constructed and localized by introducing new auxiliary variables, and then n th Backlund transformation in terms of determinant is provided. With the help of the consistent tanh expansion (CTE) method, the explicit soliton-cnoidal Wave Interaction solutions are obtained from the last consistent differential equation.
-
nonlocal symmetry darboux transformation and soliton cnoidal Wave Interaction solution for the shallow water Wave equation
arXiv: Exactly Solvable and Integrable Systems, 2017Co-Authors: Junchao ChenAbstract:In classical shallow water Wave (SWW) theory, there exist two integrable one-dimensional SWW equation [Hirota-Satsuma (HS) type and Ablowitz-Kaup-Newell-Segur (AKNS) type] in the Boussinesq approximation. In this paper, we mainly focus on the integrable SWW equation of AKNS type. The nonlocal symmetry in form of square spectral function is derived starting from its Lax pair. Infinitely many nonlocal symmetries are presented by introducing the arbitrary spectrum parameter. These nonlocal symmetries can be localized and the SWW equation is extended to enlarged system with auxiliary dependent variables. Then Darboux transformation for the prolonged system is found by solving the initial value problem. Similarity reductions related to the nonlocal symmetry and explicit group invariant solutions are obtained. It is shown that the soliton-cnoidal Wave Interaction solution, which represents soliton lying on a cnoidal periodic Wave background, can be obtained analytically. Interesting characteristics of the Interaction solution between soliton and cnoidal periodic Wave are displayed graphically.
-
consistent riccati expansion solvability and soliton cnoidal Wave Interaction solution of a 2 1 dimensional korteweg de vries equation
Applied Mathematics Letters, 2017Co-Authors: Junchao ChenAbstract:Abstract In this paper, a ( 2 + 1 ) -dimensional KdV equation is investigated by using the consistent Riccati expansion (CRE) method proposed by Lou (2015). It is proved that the ( 2 + 1 ) -dimensional KdV equation is CRE solvable. Furthermore, soliton, cnoidal Wave and soliton–cnoidal Wave Interaction solutions are obtained explicitly from different special solutions of the modified Schwarzian equation.
H Behera - One of the best experts on this subject based on the ideXlab platform.
-
hydroelastic analysis of gravity Wave Interaction with submerged horizontal flexible porous plate
Journal of Fluids and Structures, 2015Co-Authors: H Behera, T SahooAbstract:The present study deals with the surface gravity Wave Interaction with submerged horizontal flexible porous plate under the assumption of small amplitude water Wave theory and structural response. The flexible porous plate is modeled using the thin plate theory and Wave past porous structure is based on the generalized porous Wavemaker theory. The Wave characteristics due to the Interaction of gravity Waves with submerged flexible porous structure are studied by analyzing the complex dispersion relation using contour plots. Three different problems such as (i) Wave scattering by a submerged flexible porous plate, (ii) Wave trapping by submerged flexible porous plate placed at a finite distance from a rigid wall and (iii) Wave reflection by a rigid wall in the presence of a submerged flexible porous plate are analyzed. The role of flexible porous plate in attenuating Wave height and creating a tranquility zone is studied by analyzing the reflection, transmission and dissipation coefficients for various Wave and structural parameters such as angle of incidence, depth of submergence, plate length, compression force and structural flexibility. In the case of Wave trapping, the optimum distance between the porous plate and rigid wall for Wave reflection is analyzed in different cases. In addition, effects of various physical parameters on free surface elevation, plate deflection, Wave load on the plate and rigid wall are studied. The present approach can be extended to deal with acoustic Wave Interaction with flexible porous plates.
-
gravity Wave Interaction with porous structures in two layer fluid
Journal of Engineering Mathematics, 2014Co-Authors: H Behera, T SahooAbstract:Oblique Wave Interaction with rectangular porous structures of various configurations in two-layer fluid are analyzed in finite water depth. Wave characteristics within the porous structure are analyzed based on plane Wave approximation. Oblique Wave scattering by a porous structure of finite width and Wave trapping by a porous structure near a wall are studied under small amplitude Wave theory. The effectiveness of three types of porous structures—a semi-infinite porous structure, a finite porous structure backed by a rigid wall, and a porous structure with perforated front and rigid back walls—in reflecting and dissipating Wave energy are analyzed. The reflection and transmission coefficients for Waves in surface and internal modes and the hydrodynamic forces on porous structures of the aforementioned configurations are computed for various physical parameters in two-layer fluid. The eigenfunction expansion method is used to deal with Waves past the porous structure in two-layer fluid assuming the associated eigenvalues are distinct. An alternate procedure based on the Green’s function technique is highlighted to deal with cases where the roots of the dispersion relation in the porous medium coalesce. Long Wave equations are derived and the dispersion relation is compared with that derived based on small amplitude Wave theory. The present study will be of significant importance in the design of various types of coastal structures used in the marine environment for the reflection and dissipation of Wave energy.
M Schneller - One of the best experts on this subject based on the ideXlab platform.
-
double resonant fast particle Wave Interaction
Nuclear Fusion, 2012Co-Authors: M Schneller, Ph Lauber, M Brudgam, S D Pinches, S GunterAbstract:In future fusion devices fast particles must be well confined in order to transfer their energy to the background plasma. Magnetohydrodynamic instabilities like toroidal Alfv?n eigenmodes or core-localized modes such as beta-induced Alfv?n eigenmodes and reversed shear Alfv?n eigenmodes, both driven by fast particles, can lead to significant losses. This is observed in many ASDEX Upgrade discharges. This study applies the drift-kinetic HAGIS code with the aim of understanding the underlying resonance mechanisms, especially in the presence of multiple modes with different frequencies. Of particular interest is the resonant Interaction of particles simultaneously with two different modes, referred to as ?double-resonance?. Various mode overlapping scenarios with different q profiles are considered. It is found that, depending on the radial mode distance, double-resonance is able to enhance growth rates as well as mode amplitudes significantly. Surprisingly, no radial mode overlap is necessary for this effect. Quite the contrary is found: small radial mode distances can lead to strong nonlinear mode stabilization of a linearly dominant mode.
-
double resonant fast particle Wave Interaction
arXiv: Plasma Physics, 2012Co-Authors: M Schneller, Ph Lauber, M Brudgam, S D Pinches, S GunterAbstract:In future fusion devices fast particles must be well confined in order to transfer their energy to the background plasma. Magnetohydrodynamic instabilities like Toroidal Alfv\'en Eigenmodes or core-localized modes such as Beta Induced Alfv\'en Eigenmodes and Reversed Shear Alfv\'en Eigenmodes, both driven by fast particles, can lead to significant losses. This is observed in many ASDEX Upgrade discharges. The present study applies the drift-kinetic HAGIS code with the aim of understanding the underlying resonance mechanisms, especially in the presence of multiple modes with different frequencies. Of particular interest is the resonant Interaction of particles simultaneously with two different modes, referred to as 'double-resonance'. Various mode overlapping scenarios with different q profiles are considered. It is found that, depending on the radial mode distance, double-resonance is able to enhance growth rates as well as mode amplitudes significantly. Surprisingly, no radial mode overlap is necessary for this effect. Quite the contrary is found: small radial mode distances can lead to strong nonlinear mode stabilization of a linearly dominant mode.
