## THERMAL SCIENCE

International Scientific Journal

### SYMMETRY REDUCTION A PROMISING METHOD FOR HEAT CONDUCTION EQUATIONS

**ABSTRACT**

Though there are many approximate methods, e. g., the variational iteration method and the homotopy perturbation, for non-linear heat conduction equations, exact solutions are needed in optimizing the heat problems. Here we show that the Lie symmetry and the similarity reduction provide a powerful mathematical tool to searching for the needed exact solutions. Lie algorithm is used to obtain the symmetry of the heat conduction equations and wave equations, then the studied equations are reduced by the similarity reduction method.

**KEYWORDS**

PAPER SUBMITTED: 2018-03-15

PAPER REVISED: 2018-08-08

PAPER ACCEPTED: 1970-01-01

PUBLISHED ONLINE: 2019-09-14

**THERMAL SCIENCE** YEAR

**2019**, VOLUME

**23**, ISSUE

**4**, PAGES [2219 - 2227]

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