This work presents a new analytical method to transform exact solutions of linear diffusion equations into exact ones for nonlinear advection-diffusion models. The proposed formulation, based on Bäcklund transformations, is employed to obtain velocity fields for the unsteady two-dimensional Helmholtz equation, starting from analytical solutions of a heat conduction type model.

We quantify the effects of electron thermal conduction on the properties of hot accretion flows, under the assumption of spherical symmetry. Electron heat conduction is important for low accretion rate systems where the electron cooling time is longer than the conduction time of the plasma, such as Sgr A* in the Galactic Center. For accretion flows with density profiles similar to the Bondi sol...

A nonlinear heat conduction equation is studied, and the maximal thermo-geometric parameter in the equation is analytically determined, above which thermal instability occurs. The first-order result yields an acceptable error, and the variational iteration method is recommended for a higher accurate prediction. 2010 Mathematics Subject Classification: 35K05, 35Q79, 80A20, 34B15

Topics Direct Approach for Discrete Systems Strong and Weak Forms for One-Dimensional Problems Second order boundary value problems (1D) Scalar field problems: heat conduction, advection-diffusion Triangular elements Computer implementation Isoparametric elements Numerical integration Vector field problems: elasticity equations Beam elements Eigenvalue problems Time dependent problems Special t...

In this paper the optimal control of boundary heat flux in a 2-D solid body with an arbitrary shape is performed in order to achieve the desired temperature distribution at a given time interval. The boundary of the body is subdivided into a number of components. On each component a time-dependent heat flux is applied which is independent of the others. Since the thermophysical properties are t...

Small scale thermal devices, such as micro heater, have led researchers to consider more accurate models of heat in thermal systems. Moreover, biological applications of heat transfer such as simulation of temperature field in laser surgery is another pathway which urges us to re-examine thermal systems with modern ones. Non-Fourier heat transfer overcomes some shortcomings of Fourier heat tran...