189 citations · 267 across the 14 of their papers we have counts for
16 papers
Log-law recovery through reinforcement-learning wall model for large-eddy simulation
Aurélien Vadrot, Xiang I. A. Yang, H. Jane Bae +1
This paper focuses on the use of reinforcement learning (RL) as a machine-learning (ML) modeling tool for near-wall turbulence. RL has demonstrated its effectiveness in solving hig…
POD-mode-augmented wall model and its applications to flows at non-equilibrium conditions
Christoffer Hansen, Xiang IA Yang, Mahdi Abkar
Insights gained from modal analysis are invoked for predictive large-eddy simulation (LES) wall modeling. Specifically, we augment the law of the wall (LoW) by an additional mode b…
Survey of machine learning wall models for large eddy simulation
Aurélien Vadrot, Xiang I. A. Yang, Mahdi Abkar
This survey investigates wall modeling in large eddy simulations (LES) using data-driven machine learning (ML) techniques. To this end, we implement three ML wall models in an open…
Data-driven quantification of model-form uncertainty in Reynolds-averaged simulations of wind farms
Ali Eidi, Navid Zehtabiyan-Rezaie, Reza Ghiassi +2
Computational fluid dynamics using the Reynolds-averaged Navier-Stokes (RANS) remains the most cost-effective approach to study wake flows and power losses in wind farms. The under…
Second Moment Closure Modeling and DNS of Stratified Shear Layers
Naman Jain, Hieu T. Pham, Xinyi Huang +3
Buoyant shear layers are encountered in many engineering and environmental applications and have been studied by researchers in the context of experiments and modeling for decades.…
LES wall modeling for heat transfer at high speeds
Peng E. S. Chen, Yu Lv, Haosen H. A. Xu +2
A practical application of universal wall scalings is near-wall turbulence modeling. In this paper, we exploit temperature's semi-local scaling [Patel, Boersma, and Pecnik, {Scalar…
The diverse nature of small-scale turbulence
Ke-Qi Ding, Kun Yang, Xiang Yang +2
The self-similar Richardson cascade admits two logically possible scenarios of small-scale turbulence at high Reynolds numbers. In the first scenario, eddies' population densities…
Model-form uncertainty quantification in RANS simulations of wakes and power losses in wind farms
Ali Eidi, Reza Ghiassi, Xiang Yang +1
Reynolds-averaged Navier-Stokes (RANS) is one of the most cost-efficient approaches to simulate wind-farm-atmosphere interactions. However, the applicability of RANS-based methods…
Determining a priori a RANS model's applicable range via global epistemic uncertainty quantification
Xinyi Huang, Naman Jain, Mahdi Abkar +2
Calibrating a Reynolds-averaged Navier-Stokes (RANS) model against data leads to an improvement. Determining {\it a priori} if such an improvement generalizes to flows outside the…
Grid-point and time-step requirements for direct numerical simulation and large-eddy simulation
Xiang I. A. Yang, Kevin Patrick Griffin
We revisit the grid-point requirement estimates in Choi and Moin [Phys. Fluid, 24, 011702 (2012)] and establish more general grid-point requirements for direct numerical simulation…
3D flow motions in the viscous sublayer
Santosh Kumar Sankar, Xinyi Huang, Xiang Yang +1
We employ novel digital Fresnel reflection holography to capture the 3D flows within the viscous sublayer of a smooth-wall turbulent channel flow at Reτ=400. The measurements revea…
On skin friction in wall-bounded turbulence
Zhenhua Xia, Peng Zhang, Xiang I. A. Yang
In this paper, we derive mathematical formulas for the skin friction coefficient in wall-bounded turbulence based on the Reynolds averaged streamwise momentum equation and the tota…
Bifurcation and multiple states in plane Couette flow with spanwise rotation
Xiang Yang, Zhenhua Xia
We present a derivation that begins with the Navier--Stokes equation and ends with a prediction of multiple statistically stable states identical to those observed in a spanwise ro…
Direct numerical simulations of turbulent channel flow under transcritical conditions
Peter C. Ma, Xiang I. A. Yang, Matthias Ihme
Turbulent flows under transcritical conditions are present in regenerative cooling systems of rocker engines and extraction processes in chemical engineering. The turbulent flows a…
Statistics of turbulence in the energy-containing range of Taylor-Couette compared to canonical wall-bounded flows
Dominik Krug, Xiang I. A. Yang, Charitha M. de Silva +4
Considering structure functions of the streamwise velocity component in a framework akin to the extended self-similarity hypothesis (ESS), de Silva \textit{et al.} (\textit{J. Flui…
Extended self-similarity in moment-generating-functions in wall-bounded turbulence at high Reynolds number
Xiang I. A. Yang, Charles Meneveau, Ivan Marusic +1
In wall-bounded turbulence, the moment generating functions (MGFs) of the streamwise velocity fluctuations develop power-law scaling as a function of th…