A SOLUTION-ADAPTIVE MESH PROCEDURE FOR PREDICTING CONFINED EXPLOSIONS

Explosion hazards constitute a significant practical problem for indus try. In response to the need for better-resolved predictions for confi ned explosions, and particularly with a view to advancing safety cases for offshore oil and gas rigs, an existing unstructured, adaptive mes h, finite volume Reynolds-averaged Navier-Stokes computational fluid d ynamics code (originally developed to handle non-combusting turbomachi nery hows) has been modified to include a one-equation, eddy break-up combustion model. Two benefits accrue from the use of unstructured, so lution-adaptive meshes: first, great geometrical flexibility is possib le; second, automatic mesh adaptation allows computational effort to b e focused on important or interesting areas of the flow by enhancing m esh resolution only where it is required. In the work reported here, t he mesh was adaptively refined to achieve flame front capture, and it is shown that this results in a 10%-33% CPU saving for two-dimensional calculations and a saving of between 57% and 70% for three-dimensiona l calculations. The geometry of the three-dimensional calculations was relatively simple, and it may be expected that the use of unstructure d meshes for truly complex geometries will result in CPU savings suffi cient to allow an order-of-magnitude increase in either complexity or resolution. (C) 1998 John Wiley & Sons, Ltd.