Inertia-driven and elastoinertial viscoelastic turbulent channel flow simulated with a hybrid pseudo-spectral/finite-difference numerical scheme

Zhu, Lu; Li, Xi

doi:10.1016/j.jnnfm.2020.104410

Cited by 13 publications

(15 citation statements)

References 73 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To this end, addition of AD mainly affects/dissipates small-scale elastic flow structures (see figure 4). This is consistent with the previous findings regarding the influence of AD on simulations of inertia-driven and elasto-inertial viscoelastic turbulence (Sid et al 2018;Gupta & Vincenzi 2019;Zhu & Xi 2020). Based on our earlier studies of the curvature dependence of viscoelastic TC turbulence (Song et al 2019), decreasing the gap (larger η) is expected to lead to weakening and elimination of the small-scale elastic GV, due to the fact that elastic effects are more significant at smaller η.…”

Section: Code Assessmentsupporting

confidence: 93%

“…This is consistent with the previous findings regarding the influence of AD on simulations of inertia-driven and elasto-inertial viscoelastic turbulence (Sid et al. 2018; Gupta & Vincenzi 2019; Zhu & Xi 2020). Based on our earlier studies of the curvature dependence of viscoelastic TC turbulence (Song et al.…”

Section: Problem Formulation and Computational Detailssupporting

confidence: 93%

“…Adding a global AD term κ∇ 2 C to this equation is a common and successful practice for attaining numerical stability in inertially dominated turbulent flows (Sureshkumar, Beris & Avgousti 1995;Sureshkumar et al 1997;Li et al 2006). To ensure accuracy of the solution in the presence of AD, extensive studies have been performed where the influence of Schmidt number Sc[= (Reκ) −1 ] on the overall flow dynamics has been studied (Gupta & Vincenzi 2019;Zhu & Xi 2020). Specifically, it has been shown that a small diffusivity [Sc ∼ O(10 −1 )] will not modify the essential features of the velocity and polymer conformation tensor fields in inertially dominated turbulent flows.…”

Section: Methodsmentioning

confidence: 99%

“…Specifically, it has been shown that convergent and accurate solutions can be obtained when the convective term in the conformation tensor evolution equation is discretized using techniques appropriate for hyperbolic equations (Vaithianathan et al 2006). To this end, in this study we have used a proven technique (Zhu & Xi 2020), namely, a pseudo-spectral/finite-difference hybrid method (HM) to simulate the viscoelastic TC flow. Specifically, the convective term in the conformation tensor evolution equation (2.3) is discretized with a second-order conservative total variation diminishing finite-difference scheme with the MINMOD limiter (Yu & Kawaguchi 2004); a pseudo-spectral method (SM) discretization is used for all other terms, which maximally preserves accuracy and efficiency.…”

Section: Methodsmentioning

confidence: 99%

“…2006). To ensure accuracy of the solution in the presence of AD, extensive studies have been performed where the influence of Schmidt number on the overall flow dynamics has been studied (Gupta & Vincenzi 2019; Zhu & Xi 2020). Specifically, it has been shown that a small diffusivity [] will not modify the essential features of the velocity and polymer conformation tensor fields in inertially dominated turbulent flows.…”

Section: Problem Formulation and Computational Detailsmentioning

confidence: 99%

See 4 more Smart Citations

Direct numerical simulation of inertio-elastic turbulent Taylor–Couette flow

et al. 2021

View full text Add to dashboard Cite

The flow physics of inertio-elastic turbulent Taylor–Couette flow for a radius ratio of $0.5$ in the Reynolds number ( $Re$ ) range of $500$ to $8000$ is investigated via direct numerical simulation. It is shown that as $Re$ is increased the turbulence dynamics can be subdivided into two distinct regimes: (i) a low $Re \leqslant 1000$ regime where the flow physics is essentially dominated by nonlinear elastic forces and the main contribution to transport and mixing of momentum, stress and energy comes from large-scale flow structures in the bulk region and (ii) a high $Re \geqslant 5000$ regime where inertial forces govern the flow physics and the flow dynamics is mainly governed by small-scale flow structures in the near-wall region. Flow–microstructure coupling analysis reveals that the elastic Görtler instability in the near-wall region is triggered via significant polymer extension and commensurately high hoop stresses. This instability gives rise to small-scale elastic vortical structures identified as elastic Görtler vortices which are present at all $Re$ considered. In fact, these vortices develop herringbone streaks near the inner wall that have a longer average life span than their Newtonian counterparts due to their elastic origin. Examination of the budgets of mean streamwise enstrophy, mean kinetic energy, turbulent kinetic energy and Reynolds shear stress demonstrates that increasing fluid inertia hinders the generation of elastic stresses, leading to a monotonic reduction of the elastic-related effects on the flow physics.

show abstract