Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • finite element method  (6)
  • Numerical Methods and Modeling  (5)
  • Free surface  (2)
  • Mild-slope equation  (2)
  • 1
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 14 (1998), S. 9-22 
    ISSN: 1069-8299
    Schlagwort(e): finite element method ; optimal control theory ; Navier-Stokes equations ; Lagrange multipliers ; adjacent equations ; Sakawa-Shindo method ; Engineering ; Numerical Methods and Modeling
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: This work presents control of vorticity for buoyancy-driven flows. The governing set of equations includes Navier-Stokes and heat transfer equations. The basic formulation for the control problem is derived using Lagrange multipliers and the Pontryagin minimum principle. Control values are found using the Sakawa-Shindo method. Control was accomplished using velocity components. Numerical examples present control of vorticity for Rayleigh-Bernard convection in an enclosed cavity for a wide range of Ra numbers. The current formulation proved reliable and fast. Optimal control was obtained and turned out to be adequate. © 1998 John Wiley & Sons, Ltd.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 22 (1996), S. 43-66 
    ISSN: 0271-2091
    Schlagwort(e): multiple-level model ; finite element method ; open boundary condition ; tidal current analysis ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: The results of a research project to verify the newly improved multiple- level model for 3D tidal current analysis in Tokyo Bay are presented. The improved multiple-level model includes additional effects due to Coriolis force, river inflows and wind shear stresses. Furthermore, a new numerical treatment of the open boundary condition was applied which effectively eliminated the spurious reflective waves often generated by various numerical methods simulating free surface flows. The mean (time-averaged or residual) and tidal currents in Tokyo Bay were simulated as examples to demonstrate the validity and capability of the newly improved multiple-level model. A series of numerical experiments was conducted to carefully examine the tidal circulations affected by the forcing factors of Coriolis force, river inflows and wind shears, both individually and combined. The numerical results demonstrated that the effects of each forcing term are physically reasonable, with the wind shear effect being the most significant and the case including all forcing terms being in best overall agreement with the field data collected in Tokyo Bay by the Ministry of Transportation. This study has contributed not only to the verification of the newly improved multiple-level model but also to the enhancement of the accuracy of numerical simulations of three-dimensional flow in coastal waters by this model.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 40 (1997), S. 1015-1024 
    ISSN: 0029-5981
    Schlagwort(e): parameter identification ; thermal conduction ; sensitivity equation ; adjoint equation ; finite element method ; Engineering ; Numerical Methods and Modeling
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: This paper deals with the inverse analysis of a thermal conduction problem, in which the thermal conductivity is identified as an unknown parameter, which is determined so as to minimize the cost function represented by the square of the difference between the computed and observed temperatures at pre-assigned observation points. To minimize the cost function, both sensitivity equation and adjoint equation methods can be adopted. The sensitivity equation can be introduced by differentiating the governing equation directly. The sensitivity coefficient is obtained by the sensitivity equation. The adjoint equation is introduced via a variational approach using a Lagrange multiplier. The Lagrange multiplier is solution to an adjoint equation. Both sensitivity coefficient and Lagrange multiplier are used to calculate the gradient of the cost function. The purpose of this paper is to compare the sensitivity equation and adjoint equation methods from the convergence and computational efficiency points of view. © 1997 by John Wiley & Sons, Ltd.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 7 (1987), S. 953-984 
    ISSN: 0271-2091
    Schlagwort(e): Navier - Stokes equations ; Lagrangian method ; Finite element method ; Galerkin formulatiion ; Linear interpolation ; Free surface ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: A new Lagrangian finite element formulation is presented for time-dependent incompressible free surface fluid flow problems described by the Navier-Stokes equations. The partial differential equations describing the continuum motion of the fluid are discretized using a Galerkin procedure in conjunction with the finite element approximation. Triangular finite elements are used to represent the dependent variables of the problem. An effective time integration procedure is introduced and provides a viable computational method for solving problems with equality of representation of the pressure and velocity fields. Its success has been attributed to the strict enforcement of the continuity constraint at every stage of the iterative process. The capabilities of the analysis procedure and the computer programs are demonstrated through the solution of several problems in viscous free surface fluid flow. Comparisons of results are presented with previous theoretical, numerical and experimental results.
    Zusätzliches Material: 24 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 8 (1988), S. 559-578 
    ISSN: 0271-2091
    Schlagwort(e): Boundary-type finite element method ; Helmholz equation ; Mild-slope equation ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: The boundary-type finite element method has been investigated and applied to the Helmholz and mild-slope equations. Four types of interpolation function are examined based on trigonometric function series. Three-node triangular, four-node quadrilateral, six-node triangular and eight-node quadrilateral elements are tested; these are all non-conforming elements. Three types of numerical example show that the three-node triangular and four-node quadrilateral elements are useful for practical analysis.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 20 (1995), S. 789-801 
    ISSN: 0271-2091
    Schlagwort(e): identification ; optimal control ; finite element method ; temperature control system ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: To avoid the use of pesticides on putting greens of golf courses, a temperature regulator system is strongly recommended nowadays in Japan. To maintain grass on the putting green without pesticide, the temperature of the ground should be controlled. This system consists of a cooling machine and buried pipes in the ground. The temperature of the water in the pipes cannot be regulated. In this paper, both identification and control problems are presented by the minimization technique and applied to a practical problem. To establish the system, it is important to obtain accurate parameters which are included in the governing equation. These parameters can be determined by parameter identification. The conjugate gradient method is used for the parameter identification procedure. The control problem aims to make the temperature at arbitrary points close to the objective temperature. The discrete-time dynamic programming is used for the control procedure.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 13 (1991), S. 805-840 
    ISSN: 0271-2091
    Schlagwort(e): Finite element method ; Lagrangian description ; Fractional step method ; Navier-Stokes equation ; Linear interpolation ; Free surface ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: This paper presents a finite element analysis based on the Lagrangian description for unsteady incompressible viscous fluid flow with a free surface. The behaviour of the fluid is expressed by the unsteady Navier-Stokes equation. For numerical integration in time the fractional step method is used. This method is useful because one can use the same linear interpolation functions for both velocity and pressure. In this paper, four variations of the fractional step method are presented and the numerical results are compared. To confirm the effectiveness of these methods, solitary wave propagation is analysed.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 27 (1998), S. 139-157 
    ISSN: 0271-2091
    Schlagwort(e): hydrodynamic stability ; finite element method ; incompressible cavity flow ; Arnold's method ; Engineering ; Numerical Methods and Modeling
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: Numerical methods have been applied to theoretical studies of instability and transition to turbulence. In this study an analysis of the linear stability of incompressible flow is undertaken. By means of the finite element method the two-dimensional base flow is computed numerically over a range of Reynolds numbers and is perturbed with three-dimensional disturbances. The partial differential equations governing the evolution of perturbation are obtained from the non-linear Navier-Stokes equations with a slight compressibility by using linear stability and normal mode analysis. In terms of the finite element discretization a non-singular generalized eigenproblem is formulated from these equations whose solution gives the dispersion relation between complex growth rate and wave number. This study presents stability curves to identify the critical Reynolds number and critical wavelength of the neutral mode and discusses the mechanism of instability. The stability of lid-driven cavity flow is examined. Taylor-Göertler-like vortices in the cavity are obtained by means of reconstruction of three-dimensional flows. © 1998 John Wiley & Sons, Ltd.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 28 (1998), S. 95-112 
    ISSN: 0271-2091
    Schlagwort(e): square columns in tandem ; finite element method ; improved BTD ; 3D computation ; aerodynamic characteristics ; Engineering ; Numerical Methods and Modeling
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: Two- (2D) and three-dimensional (3D) finite element analyses for flow around two square columns in tandem arrangement were performed with various column spacings and Reynolds numbers. The computed values were compared with the wind-tunnel results in terms of the aerodynamic characteristics of the leeward column. In most 2D computations, strong vortices were formed behind the windward column, irrespective of widely changed Reynolds numbers. This was different from the experimental phenomena of equivalent spacing, so that the computed time-averaged pressure coefficients were not identical to the experimental values except when the distance between the two columns was adequately wide or narrow. On the other hand, in 3D computation, distinct differences in flow structures behind the column were observed between Reynolds numbers of 103 and 104 and the pressure coefficient in the 3D analysis with Re=104 agreed well with the experimental value. Thus, the effectiveness of 3D computations and Reynolds number effects on the flow around two square columns have been confirmed. © 1998 John Wiley & Sons, Ltd.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 8 (1988), S. 65-79 
    ISSN: 0271-2091
    Schlagwort(e): Boundary-type finite element method ; Mild-slope equation ; Wave diffraction-refraction ; Harbour oscillation ; Co non-conforming element ; Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: A new combinative method of boundary-type finite elements and boundary solutions is presented to study wave diffraction-refraction and harbour oscillation problems. The numerical model is based on the mild-slope equation. The key feature of this method is that the discretized matrix equation can be formulated only by the calculation of a line integral, since the interpolation equation which satisfies the governing equation in each element is used. The numerical solutions are compared with existing analytical, experimental, observed and other numerical results. The present method is shown to be an effective and accurate method for water surface wave problems.
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...