Predictions of Reynolds and Nusselt numbers in turbulent convection using machine-learning models

S Bhattacharya, MK Verma, A Bhattacharya - Physics of Fluids, 2022 - pubs.aip.org
In this paper, we develop a multivariate regression model and a neural network model to
predict the Reynolds number (Re) and Nusselt number in turbulent thermal convection. We …

Critical Prandtl number for heat transfer enhancement in rotating convection

M Anas, P Joshi - Physical Review Letters, 2024 - APS
Rotation, which stabilizes flow, can enhance the heat transfer in Rayleigh-Bénard
convection (RBC) through Ekman pumping. In this Letter, we present the results of our direct …

Revisiting Reynolds and Nusselt numbers in turbulent thermal convection

S Bhattacharya, MK Verma, R Samtaney - Physics of Fluids, 2021 - pubs.aip.org
In this paper, we extend Grossmann and Lohse's (GL) model [S. Grossmann and D.
Lohse,“Thermal convection for large Prandtl numbers,” Phys. Rev. Lett. 86, 3316 (2001)] for …

Prandtl number dependence of the small-scale properties in turbulent Rayleigh-Bénard convection

S Bhattacharya, MK Verma, R Samtaney - Physical Review Fluids, 2021 - APS
We analyze the Prandtl number (Pr) dependence of spectra and fluxes of kinetic energy, as
well as the energy injection rates and dissipation rates, of turbulent thermal convection using …

Large-eddy simulation of Rayleigh–Bénard convection at extreme Rayleigh numbers

R Samuel, R Samtaney, MK Verma - Physics of Fluids, 2022 - pubs.aip.org
We adopt the stretched spiral vortex sub-grid model for large-eddy simulation (LES) of
turbulent convection at extreme Rayleigh numbers. We simulate Rayleigh–Bénard …

Bolgiano-Obukhov scaling in two-dimensional Rayleigh-Bénard convection at extreme Rayleigh numbers

R Samuel, MK Verma - Physical Review Fluids, 2024 - APS
Understanding the behavior of the kinetic energy spectrum and flux in two-dimensional (2D)
turbulent thermal convection remains a challenge. In this paper, using high-resolution direct …

Regimes in rotating Rayleigh–Bénard convection over rough boundaries

VK Tripathi, P Joshi - Journal of Fluid Mechanics, 2024 - cambridge.org
The present work focuses on the effect of rough horizontal boundaries on the heat transfer in
rotating Rayleigh–Bénard convection. We measure the non-dimensional heat transfer, the …

On soliton solutions of Fokas dynamical model via analytical approaches

F Badshah, KU Tariq, M Inc, R Javed - Optical and Quantum Electronics, 2024 - Springer
Abstract The nonlinear (4+ 1)-dimensional Fokas equation (FE) has been demonstrated to
be the integrable extension of the Kadomtsev–Petviashvili (KP) and Davey–Stewartson (DS) …

Helicity segregation by Ekman pumping in laminar rotating flows with gravity orthogonal to rotation

A Ojha, M Anas, A Ranjan, P Joshi, MK Verma - Physical Review Fluids, 2022 - APS
Kinetic helicity in most geodynamo simulations has a distinct distribution above and below
the equator—it is negative in the north and positive in the south. Using direct numerical …

Deep-ultraviolet optoelectronic devices enabled by the hybrid integration of next-generation semiconductors and emerging device platforms

N Alfaraj - 2019 - repository.kaust.edu.sa
In this dissertation, the design and fabrication of deep-ultraviolet photodetectors were
investigated based on gallium oxide and its alloys, through the heterogeneous integration …