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Michael Stiassnie - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear dispersion for ocean surface waves
    Journal of Fluid Mechanics, 2018
    Co-Authors: Raphael Stuhlmeier, Michael Stiassnie
    Abstract:

    Two expressions for the nonlinear dispersion relation for gravity waves on water of constant depth are derived, one for wave fields with discrete amplitude spectra, the other for wave fields with continuous wavenumber energy spectra. Numerical examples for wave quartets and for two-dimensional Pierson–Moskowitz spectra are given, and an important possible application is discussed.

Anna Desilles - One of the best experts on this subject based on the ideXlab platform.

  • Viability approach to Hamilton-Jacobi-Moskowitz problem involving variable regulation parameters
    Networks & Heterogeneous Media, 2013
    Co-Authors: Anna Desilles
    Abstract:

    A few applications of the viability theory to the solution to the Hamilton-Jacobi-Moskowitz problems are presented. In the considered problem the Hamiltonian (fundamental diagram) depends on time, position and/or some regulation parameters. We study such a problem in its equivalent variational formulation. In this case, the corresponding lagrangian depends on the state of the characteristic dynamical system. As the Lax-Hopf formulae that give the solution in a semi-explicit form for an homogeneous lagrangian do not hold, a capture basin algorithm is proposed to compute the Moskowitz function as a viability solution of the Hamilton-Jacobi-Moskowitz problem with general conditions (including initial, boundary and internal conditions). We present two examples of applications to traffic regulation problems.

  • Viability approach to Hamilton-Jacobi-Moskowitz problem involving variable regulation parameters
    2011
    Co-Authors: Anna Desilles
    Abstract:

    We present a few applications of the viability theory to the solution to the Hamilton-Jacobi-Moskowitz problems when the Hamiltonian (fundamental diagram) depends on time, position and/or some regulation parameters. We study such a problem in its equivalent variational formulation. In this case, the corresponding lagrangian depends on the state of the characteristic dynamical system. As the Lax-Hopf formulae that give the solution in a semi-explicit form for an homogeneous lagrangian do not hold, we use a capture basin algorithm to compute the Moskowitz function as a viability solution of the Hamilton-Jacobi-Moskowitz problem with general conditions (including initial, boundary and internal conditions). We present two examples of applications. In the first one we introduce the variable speed limit as a regulation parameter. Our approach allows to compute the Moscowitz function for all values of the variable speed limit in a selected range and then to analyze its influence on the traffic flow. In particular, we study the case when the variation of the speed limit is applied locally, in space and time. Our second example deals with the local load capacity variations on the road. Such a variation can be a permanent property of the road (road narrowing) or it can be due to a temporary change of number of lanes (an accident or roadworks, for example). One can also use it as a regulation parameter by variable assignment of a supplementary lane.

Munehiko Minoura - One of the best experts on this subject based on the ideXlab platform.

  • REPRESENTATION OF PIERSON-Moskowitz TYPE SPECTRUM IN TIME DOMAIN
    1995
    Co-Authors: Shigeru Naito, Munehiko Minoura
    Abstract:

    There are two methods to generate an irregular wave numerically, one is the summation method by summing up regular waves, the other is the convolution integral method by the linear system theory. In the later method, the kernal function and a white noise are usually used. The authors have succeeded in obtaining the kernel function analytically, namely impulse response function, in the time domain of Pierson-Moskowitz type spectrum. They have confirmed this function is corrects as follows: that the spectrum of irregular waves generated numerically with this function and white noise agree well with the given P-M type wave spectrum.

  • EXPRESSION OF PIERSON-Moskowitz TYPE SPECTRUM IN TIME DOMAIN
    1993
    Co-Authors: Shigeru Naito, Munehiko Minoura
    Abstract:

    There are two methods of generating an irregular wave numerically, one is summation methods by summing up irregular waves and the other is the convolution integral method using linear system theory. In the later method, the kernal function and a white noise are usually used. The author's obtained the kernal function analytically, namely the impulse response function, in the time domain of the Pierson-Moskowitz (P-M) type spectrum. This function is important to generate an irregular wave with the convolution integral method. The spectrum of irregular waves generated numerically with this function and white noise agreed with the given P-M type wave spectrum.

Lucy Johnstone - One of the best experts on this subject based on the ideXlab platform.

Raphael Stuhlmeier - One of the best experts on this subject based on the ideXlab platform.

  • Nonlinear dispersion for ocean surface waves
    Journal of Fluid Mechanics, 2018
    Co-Authors: Raphael Stuhlmeier, Michael Stiassnie
    Abstract:

    Two expressions for the nonlinear dispersion relation for gravity waves on water of constant depth are derived, one for wave fields with discrete amplitude spectra, the other for wave fields with continuous wavenumber energy spectra. Numerical examples for wave quartets and for two-dimensional Pierson–Moskowitz spectra are given, and an important possible application is discussed.