Kavli Affiliate: Feng Wang
| First 5 Authors: Feng Wang, Feng Wang, , ,
| Summary:
As one of the major challenges for the conservative smoothed particle
hydrodynamics (SPH) method, the zero-order consistency issue, although thought
to be mitigated by the particle regularization scheme, such as the transport
velocity formulation, significantly damps the flow in a long channel for both
laminar and turbulent simulations. Building on this finding, this paper not
only thoroughly analyzes the damping reason in this pressure-driven channel
flow, but also relates this problem with the excessive numerical dissipation in
the gravity-driven free-surface flow. The common root cause of the non-physical
numerical damping in the two typical flow scenarios, the zero-order gradient
consistency residue, is exposed. The adverse influence of the background
pressure on the residue for the two scenarios is revealed and discussed. To
comprehensively understand the behavior of the residue and mitigate its
potential adverse effects, we conduct both theoretical analysis and numerical
experiments focusing on the key sensitive factors. For studying the
residue-induced non-physical energy dissipation in the gravity-driven
free-surface flow, the water depth and input dynamic pressure in the inviscid
standing wave case are tested. To investigate the velocity loss in the
pressure-driven channel flow, we examine the effects of the channel length,
resolution, and outlet pressure. The state-of-the-art reverse kernel gradient
correction technique is introduced for the two typical flows, and proved to be
effective in reducing the residue effect, but we find its correction capability
is fundamentally limited. Finally, the FDA nozzle, an engineering benchmark, is
tested to demonstrate the residue influence in a complex geometry, highlighting
the necessity of correction schemes in scenarios with unavoidable high
background pressure.
| Search Query: ArXiv Query: search_query=au:”Feng Wang”&id_list=&start=0&max_results=3