Critical Coating Radius of Spherical Particle in Thermal Radiation Environment

摘要

Because of the nonlinear nature of the problem, the solution for the critical radius has been obtained by numerical means, however, an explicit analytical solution has been obtained for three special cases.rnThe critical radius of the coating is found for a spherical particle which is subjected to a radiative and convective heat transfer environment. It is found that the critical radius of the coating increases when either convection or radiation decreases. Therefore, the existence of the critical radius depends on both the convection and radiation parameters. The critical coating radius increases for decreasing convection and radiation heat transfer. Thus, it becomes feasible to use a critical coating radius for heat transfer enhancement only for high convection or radiation heat transfer environments.