Development of Mathematical Models for Thermal Conductivities of Some Engineering Materials

Abstract

Thermal conductivity equipment was developed using locally available materials. The equipment consists of the sample holder, the thermometer probe cavity, the heating cavity and the structural wooden frame, performance evaluation was carried out using four different materials (iron, brass, mild steel and aluminum). The experimental studies were carried out at different time; 300 seconds interval (from 300 through 1500seconds) on the four materials and temperatures reading were recorded. The results of experimental studies were modeled to develop regression equations for predicting thermal conductivities of the materials. Analysis of Variance (ANOVA) and statistical t-test were carried out to validate the models at 5% level of significance. The experimental results show that Aluminum has highest thermal conductivity with respect to temperature while a linear model with coefficient of determination, R² (0.9097) was obtained. Statistical tests for each of models developed and the experimental results show that there is no significant difference at 5% level of significance. It is concluded that the models developed could be used to predict thermal conductivity for the four materials with good accuracy with respect to time.

Keywords: Performance evaluation, thermal conductivity, ANOVA