Preparing TELEMAC-2D for extremely large simulations
Yoann Adouin, Charles Moulinec, Robert W. Barber, Andrew G. Sunderland · Hydraulic Engineering Repository (HENRY) (Bundesanstalt für Wasserbau) · 2011
This paper describes the latest developments that have been carried out to prepare TELEMAC-2D for simulations using grids composed of hundreds of millions of elements.Even running modest-sized simulations involving around 2 to 10 million grid elements highlights some critical issues concerning both the grid generation and the subsequent grid pre-processing which is currently handled by the PARTEL TELEMAC system tool.A serial accelerated global mesh refinement technique is presented which allows the generation of a 425-million element grid from an existing 106million element grid in less than an hour on a fat node of an IBM POWER7 cluster.The current version of PARTEL (version 6.0) relies on METIS 4.0 as the partitioner and has two main drawbacks for extremely large simulations; namely, METIS 4.0 is highly memory consuming, and secondly, PARTEL is extremely time-consuming when performing the rest of the pre-processing stage.Four alternative partitioners are tested on large grids, and a new parallel pre-processing tool, PARTEL_P, has been designed with the aim of optimising memory consumption.This new tool allows the pre-processing of a 200-million element grid on up to 32,768 sub-domains and its output has successfully been used to evaluate the scaling performance of TELEMAC-2D on an IBM Blue Gene/P.