7 papers
Assimilation of wall-pressure measurements in direct numerical simulations of high-speed flow over a cone-flare geometry
Pierluigi Morra, Brett Tillman, Stuart Laurence +1
Ensemble-variational (EnVar) assimilation of wall-pressure measurements in direct numerical simulations of Mach 6 flow over a cone-flare is performed. The experimental data include…
Latent-space variational data assimilation in two-dimensional turbulence
Andrew Cleary, Qi Wang, Tamer A. Zaki
Starting from limited measurements of a turbulent flow, data assimilation (DA) attempts to estimate all the spatio-temporal scales of motion. Success is dependent on whether the sy…
Lighthill's mechanism and vorticity cascade in the logarithmic layer of wall turbulence
Samvit Kumar, Simon Toedtli, Tamer A. Zaki +1
We investigate Lighthill's proposed turbulent mechanism for near-wall concentration of spanwise vorticity by calculating mean flows conditioned on motion away from or toward the wa…
Accelerating Hamiltonian Monte Carlo for Bayesian Inference in Neural Networks and Neural Operators
Ponkrshnan Thiagarajan, Tamer A. Zaki, Michael D. Shields
Hamiltonian Monte Carlo (HMC) is a powerful and accurate method to sample from the posterior distribution in Bayesian inference. However, HMC techniques are computationally demandi…
Vorticity dynamics and drag for flows over a sphere and a prolate spheroid
Yifan Du, Tamer A. Zaki
The connection between the drag and vorticity dynamics for viscous flow over a bluff body is explored using the Josephson-Anderson (J-A) relation for classical fluids. The instanta…
The origin of vorticity in viscous incompressible flows
Tianrui Xiang, Gregory L. Eyink, Tamer A. Zaki
In inviscid, incompressible flows, the evolution of vorticity is exactly equivalent to that of an infinitesimal material line-element, and hence vorticity can be traced forward or…