An unstructured adaptive mesh refinement approach for computational fluid dynamics of reacting flows

• DOI: 10.1016/j.jcp.2022.111480
• Publication Date: 2022-07-16T22:25:08Z
• Authors: R.S. Cant; U. Ahmed; J. Fang; N. Chakarborty; G. Nivarti; C. Moulinec; D.R. Emerson
• Keywords: Adaptive Mesh Refinement; Octree

A new Direct Numerical Simulation (DNS) code HAMISH with Adaptive Mesh Refinement (AMR) has been developed to simulate compressible reacting flow in a computationally economical manner. The focus is on problems where high gradients of temperature, density and species mass fraction remain localised, for example within the interior structure flames. resolution requirements such local high-gradient regions often determine global mesh spacing when uniform meshes are used. numerical framework based an unstructured finite-volume approach together Runge-Kutta algorithm time-stepping. Cartesian used allows adaptive refinement de-refinement depending demands physics accuracy. utilises octree data Morton space-filling curve, allowing efficient cell division as well straightforward parallel domain decomposition. spatial discretisation scheme uses fourth-order polynomial reconstruction evaluate inter-cell fluxes. third-order three-step explicit time-marching time-stepping proportional-integral-type error control using embedded scheme. fully parallelised through decomposition over arbitrary number processors exhibits level efficiency. In this paper key capabilities demonstrated test cases. These cases include (a) simulation 1-D planar laminar premixed flames demonstrate capability AMR capturing sharp flame; (b) channel flow, which shows that capable refining boundary layer next wall; (c) 2-D expanding flame under quiescent condition, demonstrates dynamic position front; (d) 3-D non-reacting Taylor-Green vortex can deal vortical motion typical turbulent flows; (e) propagation isotropic homogeneous decaying turbulence be employed production DNS flows.