Application of optimization to the inverse problem of finding the worst-case heating configuration in a fire

Conference · Sat Jul 01 00:00:00 EDT 1995

OSTI ID:86298

Romero, V J; Eldred, M S; Bohnhoff, W J; Outka, D E

Thermal optimization procedures have been applied to determine the worst-case heating boundary conditions that a safety device can be credibly subjected to. There are many interesting aspects of this work in the areas of thermal transport, optimization, discrete modeling, and computing. The forward problem involves transient simulations with a nonlinear 3-D finite element model solving a coupled conduction/radiation problem. Coupling to the optimizer requires that boundary conditions in the thermal model be parameterized in terms of the optimization variables. The optimization is carried out over a diverse multi-dimensional parameter space where the forward evaluations are computationally expensive and of unknown duration a priori. The optimization problem is complicated by numerical artifacts resulting from discrete approximation and finite computer precision, as well as theoretical difficulties associated with navigating to a global minimum on a nonconvex objective function having a fold and several local minima. In this paper we report on the solution of the optimization problem, discuss implications of some of the features of this problem on selection of a suitable and efficient optimization algorithm, and share lessons learned, fixes implemented, and research issues identified along the way.

• Research Organization: Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 86298
• Report Number(s): SAND-95-1364C; CONF-950715-1; ON: DE95014861
• Resource Relation: Conference: 9. international conference on numerical methods in laminar and turbulent flow, Atlanta, GA (United States), 10-14 Jul 1995; Other Information: PBD: [1995]
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
99 MATHEMATICS
COMPUTERS
INFORMATION SCIENCE
MANAGEMENT
LAW
MISCELLANEOUS
ENGINEERED SAFETY SYSTEMS
HEAT TRANSFER
DETONATORS
FIRES
FINITE ELEMENT METHOD
THREE-DIMENSIONAL CALCULATIONS
ALGORITHMS
OPTIMIZATION
RADIANT HEAT TRANSFER
BOUNDARY CONDITIONS