TRANSIENT THERMAL STRESSES IN A LAMINATED SPHERICAL SHELL OF THERMOELECTRIC MATERIALS

摘要

Thermoelectric materials have many potential applications in engineering such as in thermoelectric generators, waste heat recovery industry, thermoelectric cooling devices. They can also be used in thermal protection system of supersonic space shuttles to reduce their surface temperatures. On the other hand, multilayered spherical shell structures are important structure type for thermoelectric material applications. This paper presents a transient analysis model to predict the temperature field and the associate thermal stresses in a laminated thermoelectric spherical shell subjected to a sudden temperature increase on its outer surface. The effects of applied electric current density, thermal conductivity and thickness of laminated shells on the temperature and thermal stress distributions have been obtained and shown graphically. Numerical results show that the maximum tensile hoop stress in the laminated shells can be reduced significantly at a specific applied electric current density. The thermal conductivity ratio of laminated shells has significant impact on the maximum stress level in the shells. When the thermal conductivity ratio of the inner layer to the outer layer increases, the maximum tensile hoop stress increases but the maximum compressive hoop stress decreases.