Nonlinear Hyperbolic Differential Equations Research Articles

Weakly nonlinear hyperbolic differential equation of the second order in Hilbert space

We consider nonlinear perturbations of the hyperbolic equation in the Hilbert space. Necessary and sufficient conditions for the existence of solutions of boundary-value problem for the corresponding equation and iterative procedures for their finding are obtained in the case when the operator in linear part of the problem hasn't inverse and can have nonclosed set of values. As an application we consider boundary-value problem for van der Pol equation in a separable Hilbert space.

A New Class of Coupled Systems of Nonlinear Hyperbolic Partial Fractional Differential Equations in Generalized Banach Spaces Involving the ψ–Caputo Fractional Derivative

The current study is devoted to investigating the existence and uniqueness of solutions for a new class of symmetrically coupled system of nonlinear hyperbolic partial-fractional differential equations in generalized Banach spaces in the sense of ψ–Caputo partial fractional derivative. Our approach is based on the Krasnoselskii-type fixed point theorem in generalized Banach spaces and Perov’s fixed point theorem together with the Bielecki norm, while Urs’s approach was used to prove the Ulam–Hyers stability of solutions of our system. Finally, some examples are provided in order to illustrate our theoretical results.

On an iterative method for solution of direct problem for nonlinear hyperbolic differential equations

An iterative method for solution of Cauchy problem for one-dimensional nonlinear hyperbolic differential equation is proposed in this paper. The method is based on continuous method for solution of nonlinear operator equations. The keystone idea of the method consists in transition from the original problem to a nonlinear integral equation and its successive solution via construction of an auxiliary system of nonlinear differential equations that can be solved with the help of different numerical methods. The result is presented as a mesh function that consists of approximate values of the solution of stated problem and is constructed on a uniform mesh in a bounded domain of two-dimensional space. The advantages of the method are its simplicity and also its universality in the sense that the method can be applied for solving problems with a wide range of nonlinearities. Finally it should be mentioned that one of the important advantages of the proposed method is its stability to perturbations of initial data that is substantiated by methods for analysis of stability of solutions of systems of ordinary differential equations. Solving several model problems shows effectiveness of the proposed method.

On Global Dynamics in Duffing Equation with Quasiperiodic Perturbation

An iterative method for solution of Cauchy problem for one-dimensional nonlinear hyperbolic differential equation is proposed in this paper. The method is based on continuous method for solution of nonlinear operator equations. The keystone idea of the method consists in transition from the original problem to a nonlinear integral equation and its successive solution via construction of an auxiliary system of nonlinear differential equations that can be solved with the help of different numerical methods. The result is presented as a mesh function that consists of approximate values of the solution of stated problem and is constructed on a uniform mesh in a bounded domain of two-dimensional space. The advantages of the method are its simplicity and also its universality in the sense that the method can be applied for solving problems with a wide range of nonlinearities. Finally it should be mentioned that one of the important advantages of the proposed method is its stability to perturbations of initial data that is substantiated by methods for analysis of stability of solutions of systems of ordinary differential equations. Solving several model problems shows effectiveness of the proposed method.

Existence and uniqueness of solutions for nonlinear hyperbolic fractional differential equation with integral boundary conditions

<p>In this paper, we investigate the existence and uniqueness of solutions for second order nonlinear fractional differential equation with integral boundary conditions. Our result is an application of the Banach contraction principle and the Krasnoselskii fixed point theorem.</p>

Sharp convolution and multiplication estimates in weighted spaces

We establish sharp convolution and multiplication estimates in weighted Lebesgue, Fourier Lebesgue and modulation spaces. We cover, especially some results in [L. Hörmander, Lectures on Nonlinear Hyperbolic Differential Equations (Springer, Berlin, 1997); S. Pilipović, N. Teofanov and J. Toft, Micro-local analysis in Fourier Lebesgue and modulation spaces, II, J. Pseudo-Differ. Oper. Appl.1 (2010) 341–376]. The results are also related to some results by Iwabuchi in [T. Iwabuchi, Navier–Stokes equations and nonlinear heat equations in modulation spaces with negative derivative indices, J. Differential Equations248 (2010) 1972–2002].

On a Nonlinear Nonlocal Hyperbolic System Modeling Suspension Bridges

We suggest a new model for the dynamics of a suspension bridge through a system of nonlinear nonlocal hyperbolic differential equations. The equations are of second and fourth order in space and describe the behavior of the main components of the bridge: the deck, the sustaining cables and the connecting hangers. We compute all the energies involved and we derive the equations from variational principles. We then prove existence and uniqueness of a weak solution for the resulting problem.

Approximate Solution of an Optimal Control Dot Mobile Problem for a Nonlinear Hyperbolic Equation

In this article, we consider the approximate solution of an optimal control dot mobile problem for a system of nonlinear partial hyperbolic and ordinary differential equations with initial and boundary value conditions and a nonlinear optimality criterion. The use of the Fourier method of variables separation reduces the generalized solution of the initial-boundary value problem to the countable system of nonlinear integral equations (CSNIE). To ease the computational procedures, it is considered the corresponding shorter (truncated) system of nonlinear integral equations (SSNIE) instead of CSNIE. By the methods of successive approximations and integral inequalities, it is studied the one-value solvability of SSNIE for the fixed values of the control. It is estimated a permissible error with respect to the shorter generalized solution of the initial-boundary value problem. It is approximately calculated the nonlinear functional of quality under the known optimal operating influences.

Compact alternating direction implicit method to solve two-dimensional nonlinear delay hyperbolic differential equations

In this article, a high-order compact alternating direction implicit method combined with a Richardson extrapolation technique is developed to solve a class of two-dimensional nonlinear delay hyperbolic differential equations. The solvability, stability and convergence of the method are analysed simultaneously in L2- and H1-norms by the discrete energy method. Numerical experiments are provided to demonstrate the accuracy and efficiency of the schemes.

High Accuracy of Finite Element Method for a Class of Nonlinear Hyperbolic Integral Differential Equation

The hyperbolic integral differential equations are widely used in practical problems of heat conduction,nuclear reactions dynamics, viscous elastic mechanics, biomechanics, the pressure in loose medium with memory materials. We shall study a class of nonlinear hyperbolic integral differential equation in this paper. Using finite element method, we obtain some superconvergence results.

On the Goursat classification problem

In the paper, the Goursat problem--classification of nonlinear hyperbolic differential equations possessing two characteristic invariants--is considered. An algorithm for finding the characteristic invariants is described. On the basis of the algorithm implemented in REDUCE, the characteristic invariants of two Laine's equations are verified. One of them is shown to have invariants of the second and third orders. This equation shows that the Goursat problem, apparently, is still open. Computer calculations show that the characteristic invariants of the second Laine's equation given in his paper are incorrect.

Coupled longitudinal and transverse vibration of automotive belts under longitudinal excitations using analog equation method

There are many studies on vibrations of moving belts originated from automotive belt drives. These studies, however, mainly consider the nonlinear effect of the transversal vibration of the belt under transversal excitation without considering the coupling effect between the transversal and longitudinal vibrations under longitudinal excitation. In this paper, a nonlinear model is built for a standing tensioned belt periodically excited longitudinally at one end with a known amplitude and frequency and with the other end clamped, which allows for coupling between the periodic longitudinal excitation and transversal vibration. The nonlinear system is solved using the Analog Equation Method. The two coupled nonlinear hyperbolic differential equations of the system are reduced to two uncoupled linear equations pertaining to the longitudinal and transverse deformation of a substitute beam with unit longitudinal and bending stiffness, respectively. The reduced equations are under a fictitious time-dependent load distribution with the same boundary and initial conditions. The fictitious forces are established numerically from the integral expression of the oscillation solution with the requirement that the equations of motion be satisfied at discreet time intervals. It is found that the transversal vibration appears as a stable and predictable beating phenomenon due to an internal resonance from the periodic energy transfer between the longitudinal excitation and the transversal vibration, which manifests itself as a standing wave.

A sonic fix for ideal magnetogasdynamics equations using the Harten–Yee TVD scheme

Computational magnetogasdynamics (MGD) represents one of the most promising interdisciplinary computational technologies for aerospace design. However, the numerical techniques developed for the MGD equations must be able to solve correctly nonlinear hyperbolic differential equation system. In this work we present a modification of the original Harten–Yee scheme by incorporating a new sonic fix for the acoustic causality points using the finite volume technique. The proposed technique is used to simulate the coplanar MGD Riemann problem where results using the new sonic fix are compared with those given by the traditional Harten–Yee scheme. The obtained 2-D numerical results correctly satisfy the 1-D numerical solutions, and the oscillations present using the Harten–Yee traditional scheme, are reduced.

Generalized implicit Euler method for hyperbolic functional differential equations

Nonlinear hyperbolic functional differential equations with initial boundary conditions are considered. Theorems on the convergence of difference schemes and error estimates of approximate solutions are presented. The proof of the stability of the difference functional problem is based on a comparison technique. Nonlinear estimates of the Perron type with respect to the functional variable for given functions are used. Numerical examples are given (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A numerical algorithm for avascular tumor growth model

Avascular tumor growth model for multicellular spheroids is considered. The model is a moving boundary problem and consists of three types of cells. The governing equations are nonlinear hyperbolic and/or parabolic differential equations. Comparisons of the numerical solutions with the solution of the recent studies are done. The effect of the necrotic region on the tumor growth is discussed.

Wave-breaking and generic singularities of nonlinear hyperbolic equations

Wave-breaking is studied analytically first and the results are compared with accurate numerical simulations of 3D wave-breaking. We focus on the time dependence of various quantities becoming singular at the onset of breaking. The power laws derived from general arguments and the singular behaviour of solutions of nonlinear hyperbolic differential equations are in excellent agreement with the numerical results. This shows the power of the analysis by methods using generic concepts of nonlinear science.

Least-squares spectral element method for non-linear hyperbolic differential equations

The least-squares spectral element method has been applied to the one-dimensional inviscid Burgers equation which allows for discontinuous solutions. In order to achieve high order accuracy both in space and in time a space–time formulation has been applied. The Burgers equation has been discretized in three different ways: a non-conservative formulation, a conservative system with two variables and two equations: one first order linear PDE and one linearized algebraic equation, and finally a variant on this conservative formulation applied to a direct minimization with a QR-decomposition at elemental level. For all three formulations an h/p-convergence study has been performed and the results are discussed in this paper.

Oscillation of Nonlinear Hyperbolic Differential Equations with Impulses

We study oscillatory properties of solutions of nonlinear impulsive hyperbolic differential equations and find new necessary and sufficient conditions for the existence of oscillations.

Mixed problems for hyperbolic functional differential equations with unbounded delay

The phase space for nonlinear hyperbolic functional differential equations with unbounded delay is constructed. The set of axioms for generalized solutions of initial boundary value problems is presented. A theorem on the existence and continuous dependence upon initial boundary data is given. The mixed problem is transformed into a system of integral functional equations. The existence of solutions of this system is proved by the method of successive approximations and by using theorems on integral inequalities. Examples of phase spaces are given.

On the oscillatory solutions of nonlinear hyperbolic differential equations by the decomposition method

In this study, the decomposition method for the approximate solutions of the linear and nonlinear deterministic or stochastic differential equations, is given by the decomposition (Adomian) and has been investigated in general. In applying the method to the nonlinear deterministic hyperbolic equations, the concept of the Adomian polynomials has been explained and one application of the method given for the general state is obtained.