Complete heat transfer solutions of an insulated regular polyhedron by using an RPSWT model

The heat transfer characteristics for an insulated regular polyhedron (including sphere) are analyzed by using the same RPSWT model in the present study as that used by Wong and Chou previously [Energy Convers. Manage. 44 (2003) 3015]. The thermal resistance of the inner convection term and the wall conduction term in the heat transfer rate are not neglected in the present study. Thus, the complete heat transfer solution will be obtained. The present results can be applied more extensively to practical situations, such as an insulated gas tank. The results of the critical thickness tcr and the neutral thickness te are independent of the values of J (generated by the effect of the inner convection term and the wall conduction term). However, the heat transfer rates are dependent on the values of J. The present study shows that the thermal resistance of the inner convection term and the body conduction term cannot be neglected in the heat transfer equation in situations of low to medium inner convection coefficients hi and/or low to medium wall conductivities K and/or great wall thickness t1, especially in situations with small body sizes or/and great outer convection coefficients ho.