Lagrange-s Inversion Theorem and Infiltration

Implicit equations play a crucial role in Engineering. Based on this importance, several techniques have been applied to solve this particular class of equations. When it comes to practical applications, in general, iterative procedures are taken into account. On the other hand, with the improvement of computers, other numerical methods have been developed to provide a more straightforward methodology of solution. Analytical exact approaches seem to have been continuously neglected due to the difficulty inherent in their application; notwithstanding, they are indispensable to validate numerical routines. Lagrange-s Inversion Theorem is a simple mathematical tool which has proved to be widely applicable to engineering problems. In short, it provides the solution to implicit equations by means of an infinite series. To show the validity of this method, the tree-parameter infiltration equation is, for the first time, analytically and exactly solved. After manipulating these series, closed-form solutions are presented as H-functions.

Authors:

• Pushpa N. Rathie
• Prabhata K. Swamee
• André L. B. Cavalcante
• Luan Carlos de S. M. Ozelim

Keywords:

• Green-Ampt Equation
• Lagrange's Inversion Theorem
• Talsma-Parlange Equation
• Three-Parameter Infiltration Equation

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