Space–Time method for flow computations with slip interfaces and topology changes (ST-SI-TC)

Abstract

The Space-Time Variational Multiscale (ST-VMS) method was introduced to function as a moving-mesh method. It is the VMS version of the Deforming-Spatial-Domain/Stabilized ST (DSD/SST) method. It has reasonably good turbulence modeling features and serves as a core computational method. The ST Slip Interface (ST-SI) method was introduced to addresses the challenge involved in high-resolution representation of the boundary layers near spinning solid surfaces. The mesh covering a spinning solid surface spins with it and thus maintains the high-resolution representation near it. The ST-TC method was introduced for moving-mesh computation of flow problems with topology changes, such as contact between solid surfaces. It deals with the TC while maintaining high-resolution boundary layer representation near solid surfaces. The "ST-SI-TC" method we introduce here integrates the ST-SI and ST-TC methods in the ST-VMS framework. It enables accurate flow analysis when we have a spinning solid surface that is in contact with a solid surface. We present two test computations with the ST-SI-TC method, and they are both with models of flow around a rotating tire with road contact and prescribed deformation, one with a 2D model, and one with a 3D model.

A node-numbering-invariant directional length scale for simplex elements

“…119 for the coupled incompressible-flow and thermal-transport equations retains the high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces. These ST-SI methods have been applied to aerodynamic analysis of vertical-axis wind turbines, 98,48,49 thermo-fluid analysis of disk brakes, 119 flow-driven string dynamics in turbomachinery, [120][121][122] flow analysis of turbocharger turbines, [123][124][125][126] flow around tires with road contact and deformation, 115,[127][128][129][130] fluid films, 131,130 aerodynamic analysis of ram-air parachutes, 132 and flow analysis of heart valves. 116,117,111,113 In the ST-SI version presented in Ref.…”

Medical-image-based aorta modeling with zero-stress-state estimation

“…In the last 7 years, the ST computations focused on even more challenging aspects of cardiovascular fluid mechanics and FSI, including comparative studies of cerebral aneurysms [38,39], stent treatment of cerebral aneurysms [40][41][42][43][44], heart valve flow computation [45][46][47][48][49][50], aorta flow analysis [50][51][52][53], and coronary arterial dynamics [54]. The computational challenges encountered were addressed by the advances in the core methods for moving boundaries and interfaces (MBI) and FSI (see, for example, [20,21,39,45,46,48,49,[55][56][57][58][59][60][61][62][63] and references therein) and in the special methods targeting cardiovascular MBI and FSI (see, for example, [20, 37, 43, 44, 47-50, 53, 64] and references therein). For an overview of the ST MBI and FSI computations in general, see [65].…”

Compressible flows on moving domains: Stabilized methods, weakly enforced essential boundary conditions, sliding interfaces, and application to gas-turbine modeling

“…The slidinginterface formulation may be interpreted as a Discontinuous Galerkin method [61] , where the basis functions are continuous inside the interior of subdomains but not at the sliding interface. In the incompressible-flow regime, the sliding-interface formulation was recently extended to the space-time (ST) variational multiscale (VMS) method [62][63][64][65][66][67][68][69] , and the extension is called the "ST Slip Interface (ST-SI)" method [70][71][72][73][74][75][76] . In this work, we develop a compressible-flow counterpart of the sliding-interface formulation.…”