VARIABLE-COEFFICIENT FORCED BURGERS SYSTEM IN NONLINEAR FLUID MECHANICS AND ITS POSSIBLY OBSERVABLE EFFECTS

2003 ◽  
Vol 14 (09) ◽  
pp. 1207-1222 ◽  
Author(s):  
YI-TIAN GAO ◽  
XIAO-GE XU ◽  
BO TIAN

The forced Burgers equation works as a testing ground for a real turbulence, and as the qualitative model for a wide variety of problems including charge density waves, vortex lines in superconductors, disordered solids and epitaxial growth, etc. Its variable-coefficient generalizations call for better modeling of the physical situations. In this paper, we investigate a variable-coefficient generalization of the forced Burgers equation, and obtain several sets of exact soliton-like and other exact analytic solutions, via the extension of a generalized hyperbolic-function method with computerized symbolic computation. We also discuss the Wu method. We find some possibly observable effects, which might be discovered with the relevant experiments.

2001 ◽  
Vol 12 (06) ◽  
pp. 819-833 ◽  
Author(s):  
YI-TIAN GAO ◽  
BO TIAN

The variable-coefficient nonlinear evolution equations, although realistically modeling various mechanical and physical situations, often cause some well-known powerful methods not to work efficiently. In this paper, we extend the power of the generalized hyperbolic-function method, which is based on the computerized symbolic computation, to a variable-coefficient modified Kadomtsev–Petviashvili (KP) equation and a generalized variable-coefficient KP equation. New exact analytic solutions thus come out.


2004 ◽  
Vol 15 (04) ◽  
pp. 545-551 ◽  
Author(s):  
BO TIAN ◽  
YI-TIAN GAO

Phenomena on the liquid surfaces are of current importance, such as those for rivers, oceans, liquid propellant for rockets and aviation kerosene. Wave propagation on a liquid surface in the presence of surface tension is hereby investigated. Computerized symbolic computation, generalized hyperbolic-function method and Wu method are combined. Some soliton-like, exact analytic solutions are obtained for a recently-proposed (2+1)-dimensional 6th-order model. Possibly observable effects are also proposed, which certain future experiments may hopefully discover.


2015 ◽  
Vol 19 (4) ◽  
pp. 1183-1187
Author(s):  
Hong-Cai Ma ◽  
Xiao-Fang Peng ◽  
Dan-Dan Yao

By using the improved hyperbolic function method, we investigate the variable coefficient Benjamin-Bona-Mahony-Burgers equation which is very important in fluid mechanics. Some exact solutions are obtained. Under some conditions, the periodic wave leads to the kink-like wave.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Dianchen Lu ◽  
Jie Liu

The homotopy analysis method is applied to solve the variable coefficient KdV-Burgers equation. With the aid of generalized elliptic method and Fourier’s transform method, the approximate solutions of double periodic form are obtained. These solutions may be degenerated into the approximate solutions of hyperbolic function form and the approximate solutions of trigonometric function form in the limit cases. The results indicate that this method is efficient for the nonlinear models with the dissipative terms and variable coefficients.


2001 ◽  
Vol 12 (09) ◽  
pp. 1383-1389 ◽  
Author(s):  
YI-TIAN GAO ◽  
BO TIAN

The modified Kadomtsev–Petviashvili (MKP) models describe the large-scale motion of such rotating fluids as the atmosphere and oceans. Based on the computerized symbolic computation, we in this paper extend the power of the variable-coefficient balancing-act method, which is recently proposed, to a variable-coefficient MKP model. The model is re-written as a coupled set of partial differential equations, and the algorithm is re-written correspondingly. We obtain a new family of the soliton-like, exact analytic solutions, beyond the traveling waves.


2001 ◽  
Vol 12 (10) ◽  
pp. 1425-1430 ◽  
Author(s):  
YI-TIAN GAO ◽  
BO TIAN ◽  
GUANG-MEI WEI

The coupled Korteweg-de Vries (KdV) equations are important in many fields, such as nonlinear optics, fluid dynamics, supersymmetry and so on. In this paper, we modify the recently proposed variable-coefficient balancing-act algorithm, and thus obtain some exact analytic solutions for the nonintegrable Hirota–Satsuma system of coupled KdV equations, which in fluid dynamics describe interactions of two long waves with different dispersion relations.


2001 ◽  
Vol 12 (10) ◽  
pp. 1431-1437 ◽  
Author(s):  
YI-TIAN GAO ◽  
BO TIAN

Positons are a new concept in nonlinear sciences. In this paper, we report some positonic, exact analytic solutions for a variable-coefficient Korteweg-de Vries (KdV) equation arising from fluid dynamics and plasma physics.


2009 ◽  
Vol 24 (18n19) ◽  
pp. 3243-3255 ◽  
Author(s):  
GERARD 't HOOFT

Matter interacting classically with gravity in 3+1 dimensions usually gives rise to a continuum of degrees of freedom, so that, in any attempt to quantize the theory, ultraviolet divergences are nearly inevitable. Here, we investigate a theory that only displays a finite number of degrees of freedom in compact sections of space-time. In finite domains, one has only exact, analytic solutions. This is achieved by limiting ourselves to straight pieces of string, surrounded by locally flat sections of space-time. Next, we suggest replacing in the string holonomy group, the Lorentz group by a discrete subgroup, which turns space-time into a 4-dimensional crystal with defects.


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