Modeling of the free convection heat transfer from an isothermal horizontal cylinder in a vertical channel via the fuzzy logic

Abstract

In this paper fuzzy logic has been used to model and predict the experimental results of free convection heat transfer from an isothermal horizontal cylinder confined between two adiabatic walls. Experiments included vertical position of the cylinder ranging from 0 to 5 cylinder diameter. Also, Rayleigh number based on the cylinder diameter varied from 3.5 × 103 to 1.4 × 104. Experimental results showed that, at each Rayleigh number there exists an optimum vertical position for the cylinder which maximizes the Nusselt number. The value of the optimum vertical position increases as the Rayleigh number increases. A fuzzy inference system named Mamdani was used to expect the output membership functions to be fuzzy sets. It has been shown that fuzzy logic is a powerful instrument for predicting the experiments due to its low error. The average error of fuzzy prediction with respect to experimental data was found to be 0.1% for this study.