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CivilComp Proceedings
ISSN 17593433 CCP: 94
PROCEEDINGS OF THE SEVENTH INTERNATIONAL CONFERENCE ON ENGINEERING COMPUTATIONAL TECHNOLOGY Edited by:
Paper 43
Proper Generalized Decomposition  Boundary Element Method applied to the Heat Equation G. Bonithon^{1,4}, P. Joyot^{1}, F. Chinesta^{2} and P. Villon^{3}
^{1}ESTIARecherche, Bidart, France
G. Bonithon, P. Joyot, F. Chinesta, P. Villon, "Proper Generalized Decomposition  Boundary Element Method applied to the Heat Equation", in , (Editors), "Proceedings of the Seventh International Conference on Engineering Computational Technology", CivilComp Press, Stirlingshire, UK, Paper 43, 2010. doi:10.4203/ccp.94.43
Keywords: proper generalized decomposition, boundary element method, heat equation.
Summary
The boundary element method (BEM) allows efficient solution of partial
differential equations whose kernel functions are known. The heat
equation is one of these candidates when the thermal parameters are
assumed constant (linear model). When the model involves large physical
domains and time simulation intervals the amount of information that
must be stored increases significantly.
This drawback can be circumvented by using advanced strategies, as for example
the multipole technique.
We propose in this paper an alternative radically different approach that leads to a separated solution of the space and time problems within a nonincremental integration strategy. The technique is based on the use of a spacetime separated representation of the unknown field that, introduced in the residual weighting formulation, allows the definition of a separated solution of the resulting weak form. The spatial step can be then treated by invoking the standard BEM for solving the resulting steady state problem defined in the physical space. Then, the time problem that results in an ordinary first order differential equation is solved using any standard appropriate integration technique (e.g. backward finite differences). In the case of the linear and transient heat equation here considered for the sake of simplicity, the proper generalized decomposition (PGD) leads to the solution of a series of steady state diffusionreaction problems (accurately solved by using the BEM method) and a series of problems that consist of a simple time dependent ODE. Separated representations were already applied for solving transient models in the context of finite element discretizations [1,2,3,4], but they never have been used in the BEM framework, and certainly in this context the main advantage is the possibility of defining nonincremental strategies as well as the possibility of avoiding the use of spacetime kernels. In principle, this technique seems specially adapted for solving transient problems involving extremely small time steps. References
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