variavel0=RUBEM MÁRIO FIGUEIRÓ VARGAS - rvargas@eq.pucrs.br PUC-RS Abstract. By means of the fractional calculus theory and the Laplace transform, a general analytical solution is obtained for the inner wall reservoir temperature, for the case of a fluid within a reservoir submitted to a sudden change in the outside temperature. Keywords. Fractional Calculus, Transient Inner Wall Temperature, Laplace Transform.