AN EXPLICIT UNCONDITIONALLY STABLE ADAPTIVE TIME STEPPING STRATEGY WITH APPLICATIONS TO FINITE VOLUME BASED THERMAL ANALYSIS FORMULATIONS

摘要

For transient analysis of thermal problems employing finite volume based element space discretization, implicit first-order accurate direct time integration techniques have been traditionally used, although second-order accurate trapezoidal methods are also suitable. And, since a single constant time stepping procedure may not be optimal during a given analysis, especially during rapid transients, adaptive automated time stepping strategies have been suggested by the authors in conjunction with trapezoidal family of methods. Unlike past efforts in this area for thermal problems with the finite volume space discretization and trapezoidal family of direct time integration methods, the present paper describes an explicit unconditionally stable second-order accurate time integral approach with improved stability characteristics and computational attributes along with an adaptive automated time stepping strategy tailored for such approaches for applicability to general thermal analysis. Numerical test models are presented which demonstrate the applicability to general linear/nonlinear multi-dimensional thermal analysis problems.