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1.
Form invariance and approximate conserved quantity of Appell equations for a weakly nonholonomic system 下载免费PDF全文
A weakly nonholonomic system is a nonholonomic system whose constraint equations contain a small parameter. The form invariance and the approximate conserved quantity of the Appell equations for a weakly nonholonomic system are studied. The Appell equations for the weakly nonholonomic system are established, and the definition and the criterion of form invariance of the system are given. The structural equation of form invariance for the weakly nonholonomic system and the approximate conserved quantity deduced from the form invariance of the system are obtained. Finally, an example is given to illustrate the application of the results. 相似文献
2.
The approximate conserved quantity of the weakly nonholonomic mechanical-electrical system 下载免费PDF全文
We study the approximate conserved quantity of the weakly nonholonomic mechanical-electrical system.By means of the Lagrange-Maxwell equation,the Noether equality of the weakly nonholonomic mechanical-electrical system is obtained.The multiple powers-series expansion of the parameter of the generators of infinitesimal transformations and the gauge function is put into a generalized Noether identity.Using the Noether theorem,we obtain an approximate conserved quantity.An example is provided to prove the existence of the approximate conserved quantity. 相似文献
3.
An extended Boussinesq equation that models weakly nonlinear and
weakly dispersive waves on a uniform layer of water is studied in
this paper. The results show that the equation is not
Painlev\'e-integrable in general. Some particular exact travelling
wave solutions are obtained by using a function expansion method. An
approximate solitary wave solution with physical significance is
obtained by using a perturbation method. We find that the extended
Boussinesq equation with a depth parameter of $1/\sqrt 2$ is able to
match the Laitone's (1960) second order solitary wave solution of
the Euler equations. 相似文献
4.
Approximate Solution of Homotopic Mapping to Solitary Wave for Generalized Nonlinear KdV System 下载免费PDF全文
We study a generalized nonlinear KdV system is studied by using the homotopic mapping method. Firstly, a homotopic mapping transform is constructed; secondly, the suitable initial approximation is selected; then the homotopic mapping is used. The accuracy of the approximate solution for the solitary wave is obtained. From the obtained approximate solution, the homotopic mapping method exhibits a good accuracy. 相似文献
5.
Analysis of the equal width wave equation with the mesh-free reproducing kernel particle Ritz method 下载免费PDF全文
In this paper,we analyse the equal width(EW) wave equation by using the mesh-free reproducing kernel particle Ritz(kp-Ritz) method.The mesh-free kernel particle estimate is employed to approximate the displacement field.A system of discrete equations is obtained through the application of the Ritz minimization procedure to the energy expressions.The effectiveness of the kp-Ritz method for the EW wave equation is investigated by numerical examples in this paper. 相似文献
6.
ELECTROSTATIC POTENTIAL OF STRONGLY NONLINEAR COMPOSITES: HOMOTOPY CONTINUATION APPROACH 总被引:3,自引:0,他引:3 下载免费PDF全文
The homotopy continuation method is used to solve the electrostatic boundary-value problems of strongly nonlinear composite media, which obey a current-field relation of J=σ E+χ|E|2E. With the mode expansion, the approximate analytical solutions of electric potential in host and inclusion regions are obtained by solving a set of nonlinear ordinary different equations, which are derived from the original equations with homotopy method. As an example in dimension two, we apply the method to deal with a nonlinear cylindrical inclusion embedded in a host. Comparing the approximate analytical solution of the potential obtained by homotopy method with that of numerical method, we can obverse that the homotopy method is valid for solving boundary-value problems of weakly and strongly nonlinear media. 相似文献
7.
Dynamic characteristics of resonant gyroscopes study based on the Mathieu equation approximate solution 下载免费PDF全文
Dynamic characteristics of the resonant gyroscope are studied based on the Mathieu equation approximate solution in this paper.The Mathieu equation is used to analyze the parametric resonant characteristics and the approximate output of the resonant gyroscope.The method of small parameter perturbation is used to analyze the approximate solution of the Mathieu equation.The theoretical analysis and the numerical simulations show that the approximate solution of the Mathieu equation is close to the dynamic output characteristics of the resonant gyroscope.The experimental analysis shows that the theoretical curve and the experimental data processing results coincide perfectly,which means that the approximate solution of the Mathieu equation can present the dynamic output characteristic of the resonant gyroscope.The theoretical approach and the experimental results of the Mathieu equation approximate solution are obtained,which provides a reference for the robust design of the resonant gyroscope. 相似文献
8.
From the point of view of approximate symmetry, the modified
Korteweg--de Vries--Burgers (mKdV--Burgers) equation with weak
dissipation is investigated. The symmetry of a system of the
corresponding partial differential equations which approximate the
perturbed mKdV--Burgers equation is constructed and the
corresponding general approximate symmetry reduction is derived;
thereby infinite series solutions and general formulae can be
obtained. The obtained result shows that the zero-order similarity
solution to the mKdV--Burgers equation satisfies the Painlevé II
equation. Also, at the level of travelling wave reduction, the
general solution formulae are given for any travelling wave solution
of an unperturbed mKdV equation. As an illustrative example, when
the zero-order tanh profile solution is chosen as an initial
approximate solution, physically approximate similarity solutions
are obtained recursively under the appropriate choice of parameters
occurring during computation. 相似文献
9.
A reduces equation of the Kelvin wave is considered. By
using the homotopic mapping solving method, the approximate solution
is obtained. The homptopic mapping method is an analytic method,
the obtained solution can analyse operations sequentially. 相似文献
10.
The approximate solution of the magneto-hydrodynamic(MHD) boundary layer flow over a nonlinear stretching sheet is obtained by combining the Lie symmetry method with the homotopy perturbation method.The approximate solution is tabulated,plotted for the values of various parameters and compared with the known solutions.It is found that the approximate solution agrees very well with the known numerical solutions,showing the reliability and validity of the present work. 相似文献