The Experts below are selected from a list of 9309 Experts worldwide ranked by ideXlab platform

Hong Yuan - One of the best experts on this subject based on the ideXlab platform.

  • R-function Theory for Bending Problem of Shallow Spherical Shells with Polygonal Boundary
    Civil Engineering Journal, 2020
    Co-Authors: Hong Yuan, Xiongfei Yang, Huanliang Zhang, Qifeng Peng
    Abstract:

    The governing differential equations of the bending problem of simply supported shallow spherical shells on Winkler foundation are simplified to an independent equation of radial deflection. The independent equation of radial deflection is decomposed to two Laplace operators by intermediate variable. The R-function theory is applied to describe a shallow spherical shell on Winkler foundation with concave Boundary, and then a quasi-Green’s function is established by using the fundamental solution and the normalized Boundary equation. The quasi-Green’s function satisfies the Homogeneous Boundary Condition of the problem. The Laplace operators of the problem are reduced to two simultaneous Fredholm integral equations of the second kind by the Green’s formula. The singularity of the kernel of the integral equation is eliminated by choosing a suitable form of the normalized Boundary equation. The integral equations are discretized into the Homogeneous linear algebraic equations to proceed numerical computing. The singular term in the discrete equation is eliminated by the integral method. Some numerical examples are given to verify the validity of the proposed method in calculating simple Boundary Conditions and polygonal Boundary Conditions. A comparison with the ANSYS finite element (FEM) solution shows a good agreement, and it demonstrates the feasibility and efficiency of the present method.

  • application of the r function theory for the bending problem of shallow spherical shells with a dodecagon domain
    Advanced Materials Research, 2012
    Co-Authors: Hong Yuan
    Abstract:

    The R-function theory is applied to describe the dodecagon domain of shallow spherical shells on Winkler foundation, and it is also used to construct a quasi-Green’s function. The quasi-Green’s function satisfies the Homogeneous Boundary Condition of the problem. Then the differential equation of the problem is reduced to two simultaneous Fredholm integral equations of the second kind by the Green’s formula. The singularity of the kernel of the integral equation is overcome by choosing a suitable form of the normalized Boundary equation. A comparison with the ANSYS finite element solution shows a good agreement, and it demonstrates the feasibility and efficiency of the present method.

  • a quasi green s function method for the bending problem of simply supported trapezoidal shallow spherical shells on winkler foundation
    Advanced Materials Research, 2012
    Co-Authors: Hong Yuan
    Abstract:

    The quasi-Green’s function method (QGFM) is applied to solve the bending problem of simply supported trapezoidal shallow spherical shells on Winkler foundation. A quasi-Green’s function is established by using the fundamental solution and the Boundary equation of the problem. And the function satisfies the Homogeneous Boundary Condition of the problem. Then the differential equation of the problem is reduced to two simultaneous Fredholm integral equations of the second kind by the Green’s formula. The singularity of the kernel of the integral equation is overcome by choosing a suitable form of the normalized Boundary equation. The comparison with the ANSYS finite element solution shows a good agreement, and it demonstrates the feasibility and efficiency of the proposed method.

  • green quasifunction method for bending problem of clamped orthotropic trapezoidal thin plates on winkler foundation
    Applied Mechanics and Materials, 2011
    Co-Authors: Hong Yuan
    Abstract:

    The Green quasifunction method (GQM) is applied to solve the bending problem of clamped orthotropic thin plates with trapezoidal Boundary shape on Winkler foundation. Firstly the governing differential equation of the problem is reduced to the Boundary value problem of the biharmonic operator, and then it is reduced to the Fredholm integral equation of the second kind by Green’s formula. A Green quasifunction is established by using the fundamental solution and the Boundary equation of the problem. This function satisfies the Homogeneous Boundary Condition of the problem. The singularity of the kernel of the integral equation is overcome by choosing a suitable form of the normalized Boundary equation. The comparison with ANSYS finite element solution shows good agreement. The proposed method is a novel and effective mathematical one.

  • green quasifunction method for bending problem of clamped orthotropic thin plates with trapezoidal Boundary shape
    Applied Mechanics and Materials, 2011
    Co-Authors: Hong Yuan
    Abstract:

    The Green quasifunction method(GQM) is employed to solve the bending problem of clamped orthotropic thin plates with trapezoidal Boundary shape. Firstly the governing differential equation of the problem is reduced to the Boundary value problem of the biharmonic operator, and then it is reduced to the Fredholm integral equation of the second kind by Green’s formula. A Green quasifunction is established by using the fundamental solution and the Boundary equation of the problem. This function satisfies the Homogeneous Boundary Condition of the problem. The irregularity of the kernel of the integral equation is overcome by choosing a suitable form of the normalized Boundary equation. A numerical example demonstrates the feasibility and efficiency of the proposed method, and it is a novel mathematical method.

Kal Renganathan Sharma - One of the best experts on this subject based on the ideXlab platform.

  • finite speed heat conduction xv convective Homogeneous Boundary Condition in a finite slab
    Social Science Research Network, 2003
    Co-Authors: Kal Renganathan Sharma
    Abstract:

    When a finite slab at a initial temperature is suddenlv brought in contact with a fluid at a higher temperature at either of its ends, the transient temperature profile using the modified Fourier expression for heat conduction is obtained . The method of separation of variables was used. For values of small a, a < h/S where h is the heat transfer coefficient of the heating fluid and S the storage coefficient of the conduction medium (S = ρC/τ ) pulsations in temperature in time domain will occur. Then the transient temperature profile will be given by;where λ = sqrt(h ατ /ak) + nπ = sqrt(h/S/a) + nπc can be obtained from the initial Condition and the orthogonal property and is found to be 4(-1)/(2n-1) π.For large a, λ needs to be solved from equation (24). The transient solution is bifurcated.

Hiroko Morimoto - One of the best experts on this subject based on the ideXlab platform.

  • heat convection equation with nonHomogeneous Boundary Condition
    Funkcialaj Ekvacioj, 2010
    Co-Authors: Hiroko Morimoto
    Abstract:

    We consider the stationary heat convection equations and the time periodic heat convection equations (Boussinesq approximation) with non-Homogeneous Boundary Condition, and obtain the existence result similar to the Navier-Stokes equations' case.The Boundary value for the fluid velocity should satisfy so-called general outflow Condition (GOC). For the 2 or 3 dimensional bounded domain, the existence of the solution can be shown if the Boundary Condition satisfies the stringent outflow Condition (SOC). Similarly to the Navier-Stokes equations, we obtain the existence result for the 2 dimensional symmetric domain and symmetric data with the Boundary value satisfying only (GOC).

  • time periodic navier stokes flow with nonHomogeneous Boundary Condition
    Journal of Mathematical Sciences-the University of Tokyo, 2009
    Co-Authors: Hiroko Morimoto
    Abstract:

    It is known that the Navier-Stokes initial Boundary value problem for non-Homogeneous Boundary Condition has a unique local solution (e.g., O. A. Ladyzhenskaya(5)). Nevertheless, it seems to the author that there is no results for the periodic problem with non-Homogeneous Boundary Condition satisfying the general outflow Condition. We consider the periodic problem for the Navier-Stokes equations in a two dimensional bounded domain. In case of a symmet- ric domain, we obtain a periodic weak solution for symmetric Boundary values satisfying only the general outflow Condition.

Jonathan D Eldredge - One of the best experts on this subject based on the ideXlab platform.

  • acoustic modeling of perforated plates with bias flow for large eddy simulations
    Journal of Computational Physics, 2009
    Co-Authors: Simon Mendez, Jonathan D Eldredge
    Abstract:

    The study of the acoustic effect of perforated plates by Large-Eddy Simulations is reported. The ability of compressible Large-Eddy Simulations to provide data on the flow around a perforated plate and the associated acoustic damping is demonstrated. In particular, assumptions of existing models of the acoustic effect of perforated plate are assessed thanks to the Large-Eddy Simulations results. The question of modeling the effect of perforated plates is then addressed in the context of thermo-acoustic instabilities of gas turbine combustion chambers. Details are provided about the implementation, validation and application of a Homogeneous Boundary Condition modeling the acoustic effect of perforated plates for compressible Large-Eddy Simulations of the flow in combustions chambers cooled by full-coverage film cooling.

Andrey Smyshlyaev - One of the best experts on this subject based on the ideXlab platform.

  • output feedback stabilization of an unstable wave equation
    Automatica, 2008
    Co-Authors: Miroslav Krstic, Baozhu Guo, Andras Balogh, Andrey Smyshlyaev
    Abstract:

    We consider the problem of stabilization of a one-dimensional wave equation that contains instability at its free end and control on the opposite end. In contrast to classical collocated ''Boundary damper'' feedbacks for the neutrally stable wave equations with one end satisfying a Homogeneous Boundary Condition, the controllers and the associated observers designed in the paper are more complex due to the open-loop instability of the plant. The controller and observer gains are designed using the method of ''backstepping,'' which results in explicit formulae for the gain functions. We prove exponential stability and the existence and uniqueness of classical solutions for the closed-loop system. We also derive the explicit compensators in frequency domain. The results are illustrated with simulations.

  • observer based Boundary control of an unstable wave equation
    American Control Conference, 2007
    Co-Authors: Miroslav Krstic, Baozhu Guo, Andras Balogh, Andrey Smyshlyaev
    Abstract:

    We consider the problem of stabilization of a one- dimensional wave equation that contains instability at its free end and control on the opposite end. In contrast to classical collocated "Boundary damper" feedbacks for the neutrally stable wave equations with one end satisfying a Homogeneous Boundary Condition, the controllers and the associated observers designed in the paper are more complex due to the open- loop instability of the plant. The controller and observer gains are designed using the method of "backstepping," which results in explicit formulae for the gain functions. We prove exponential stability and the existence and uniqueness of classical solutions for the closed-loop system. We illustrate the applicability of our designs using simulation results.