203 citations · 1k across the 30 of their papers we have counts for
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Thermal convection in one, two, three and four dimensions
Ambrish Pandey, Harshit Tiwari, Katepalli R. Sreenivasan
We study by means of direct numerical simulations the influence of the dimensionality of convection on flow properties. We call attention to a few general principles from consideri…
Influence of plume activity on thermal convection in a rectangular cell
Ambrish Pandey, Jörg Schumacher, Matteo Parsani +1
We present three-dimensional direct numerical simulations of turbulent Rayleigh-Bénard convection in a closed rectangular box whose width and length are 0.8 and 2.4 tim…
Scale-resolved turbulent Prandtl number for Rayleigh-Bénard convection at
Shashwat Bhattacharya, Dmitry Krasnov, Ambrish Pandey +2
We present a framework to calculate the scale-resolved turbulent Prandtl number for the well-mixed and highly inertial bulk of a turbulent Rayleigh-Bénard mesoscale convecti…
Transient and steady convection in two dimensions
Ambrish Pandey, Katepalli R. Sreenivasan
We simulate thermal convection in a two-dimensional square box using the no-slip condition on all boundaries, and isothermal bottom and top walls and adiabatic sidewalls. We choose…
Turbulent mesoscale convection in the Boussinesq limit and beyond
Shadab Alam, Dmitry Krasnov, Ambrish Pandey +4
Mesoscale convection covers an intermediate scale range between small-scale turbulence and the global organization of the convection flow. It is often characterized by an order of…
Turbulent convection in rotating slender cells
Ambrish Pandey, Katepalli R. Sreenivasan
Turbulent convection in the interiors of the Sun and the Earth occurs at high Rayleigh numbers , low Prandtl numbers , and different levels of rotation rates. To understand…
Similarities between characteristics of convective turbulence in confined and extended domains
Ambrish Pandey, Dmitry Krasnov, Jörg Schumacher +2
To understand turbulent convection at very high Rayleigh numbers typical of natural phenomena, computational studies in slender cells are an option if the needed resources have to…
Combined particle image velocimetry and thermometry of turbulent superstructures in thermal convection
Sebastian Moller, Theo Käufer, Ambrish Pandey +2
Turbulent superstructures in horizontally extended three-dimensional Rayleigh-Bénard convection flows are investigated in controlled laboratory experiments in water at Prandtl numb…
Convective mesoscale turbulence at very low Prandtl numbers
Ambrish Pandey, Dmitry Krasnov, Katepalli R. Sreenivasan +1
Horizontally extended turbulent convection, termed mesoscale convection in natural systems, remains a challenge to investigate in both experiments and simulations. This is particul…
Convective heat transport in slender cells is close to that in wider cells at high Rayleigh and Prandtl numbers
Ambrish Pandey, Katepalli R. Sreenivasan
Direct numerical simulations of turbulent convection at high Rayleigh numbers in large aspect ratio cells are challenging because of the prohibitive computational resources require…
Non-Boussinesq convection at low Prandtl numbers relevant to the Sun
Ambrish Pandey, Jörg Schumacher, Katepalli R. Sreenivasan
Convection in the Sun occurs at Rayleigh numbers, , as high as , molecular Prandtl numbers, , as low as , under conditions that are far from satisfying th…
Thermal boundary layer structure in low-Prandtl-number turbulent convection
Ambrish Pandey
We study the structure of the thermal boundary layer (BL) in Rayleigh-Bénard convection for Prandtl number () 0.021 by conducting direct numerical simulations in a two-dimensio…
Non-Boussinesq low-Prandtl number convection with a temperature-dependent thermal diffusivity
Ambrish Pandey, Jörg Schumacher, Katepalli R. Sreenivasan
In an attempt to understand the role of the strong radial dependence of thermal diffusivity on the properties of convection in sun-like stars, we mimic that effect in non-Oberbeck-…
Lagrangian coherent sets in turbulent Rayleigh-Bénard convection
Christiane Schneide, Martin Stahn, Ambrish Pandey +4
Coherent circulation rolls and their relevance for the turbulent heat transfer in a two-dimensional Rayleigh--Bénard convection model are analyzed. The flow is in a closed cell of…
Probing turbulent superstructures in Rayleigh-Bénard convection by Lagrangian trajectory clusters
Christiane Schneide, Ambrish Pandey, Kathrin Padberg-Gehle +1
We analyze large-scale patterns in three-dimensional turbulent convection in a horizontally extended square convection cell by Lagrangian particle trajectories calculated in direct…
Transition to turbulence scaling in Rayleigh-Bénard convection
Jörg Schumacher, Ambrish Pandey, Victor Yakhot +1
If a fluid flow is driven by a weak Gaussian random force, the nonlinearity in the Navier-Stokes equations is negligibly small and the resulting velocity field obeys Gaussian stati…
Reversals in infinite-Prandtl-number Rayleigh-Bénard convection
Ambrish Pandey, Mahendra K. Verma, Mustansir Barma
Using direct numerical simulations, we study the statistical properties of reversals in two-dimensional Rayleigh-Bénard convection for infinite Prandtl number. We find that the lar…
Turbulent superstructures in Rayleigh-Bénard convection
Ambrish Pandey, Janet D. Scheel, Jörg Schumacher
Turbulent Rayleigh-Bénard convection displays a large-scale order in the form of rolls and cells on lengths larger than the layer height once the fluctuations of temperature and ve…
Complexity of viscous dissipation in turbulent thermal convection
Shashwat Bhattacharya, Ambrish Pandey, Abhishek Kumar +1
Using direct numerical simulations of turbulent thermal convection for Rayleigh number () between and and unit Prandtl number, we derive scaling relation…
On the Applicability of Low-Dimensional Models for Convective Flow Reversals at Extreme Prandtl Numbers
Manu Mannattil, Ambrish Pandey, Mahendra K. Verma +1
Constructing simpler models, either stochastic or deterministic, for exploring the phenomenon of flow reversals in fluid systems is in vogue across disciplines. Using direct numeri…
Transitional boundary layers in low-Prandtl-number convection
Jörg Schumacher, Vinodh Bandaru, Ambrish Pandey +1
The boundary layer structure of the velocity and temperature fields in turbulent Rayleigh-Benard flows in closed cylindrical cells of unit aspect ratio is revisited from a transiti…
Phenomenology of buoyancy-driven turbulence: recent results
Mahendra K. Verma, Abhishek Kumar, Ambrish Pandey
In this paper, we review the recent developments in the field of buoyancy-driven turbulence. Scaling and numerical arguments show that the stably-stratified turbulence with moderat…
Dynamics of large-scale quantities in Rayleigh-Bénard convection
Ambrish Pandey, Abhishek Kumar, Anando G. Chatterjee +1
In this paper we estimate the relative strengths of various terms of the Rayleigh-Bénard equations. Based on these estimates and scaling analysis, we derive a general formula for t…
Scaling of large-scale quantities in Rayleigh-Bénard convection
Ambrish Pandey, Mahendra K. Verma
We derive a formula for the Péclet number () by estimating the relative strengths of various terms of the momentum equation. Using direct numerical simulations in thre…