Improving the k-Compressibility of Hyper Reduced Order Models with Moving Sources: Applications to Welding and Phase Change Problems

ALEJANDRO COSIMO; ALBERTO CARDONA; SERGIO IDELSOHN

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2014 vol. 274 p. 237 - 263

0045-7825

The simulation of engineering problems is quite often a complex task that can be time consuming. In this context, the use of Hyper Reduced Order Models (HROMs) is a promising alternative for real-time simulations. In this work, we study the design of HROMs for non-linear problems with a moving source. Applications to nonlinear phase change problems with temperature dependent thermophysical properties are particularly considered; however, the techniques developed can be applied in other fields as well.A basic assumption in the design of HROMs is that the quantities that will be hyper-reduced are kcompressible in a certain basis in the sense that these quantities have at most k non-zero significant entries when expressed in terms of that basis. To reach the computational speed required for a real-time application, k must be small. This work examines different strategies for addressing hyper-reduction of the nonlinear terms with the objective of obtaining k-compressible signals with a notably small k. To improve performance and robustness, it is proposed that the different contributing terms to the residual are separately hyperreduced. Additionally, the use of moving reference frames is proposed to simulate and hyper-reduce cases that contain moving heat sources. Two application examples are presented: the solidification of a cube in which no heat source is present and the welding of a tube in which the problem posed by a moving heat source is analysed.