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The effect of Prandtl number on the linear stability of a plane thermal plume is analyzed under quasi-parallel approximation. At large Prandtl numbers ($Pr>100$), we found that there is an additional unstable loop whose size increases with…

Fluid Dynamics · Physics 2008-02-04 R. Lakkaraju , Meheboob Alam

In turbulent wall sheared thermal convection, there are three different flow regimes, depending on the relative relevance of thermal forcing and wall shear. In this paper we report the results of direct numerical simulations of such sheared…

A comprehensive study of the effect of wall heating or cooling on the linear, transient and secondary growth of instability in channel flow is conducted. The effect of viscosity stratification, heat diffusivity and of buoyancy are estimated…

Fluid Dynamics · Physics 2021-01-29 A. Sameen , Rama Govindarajan

Many environmental flows arise due to natural convection at a vertical surface, from flows in buildings to dissolving ice faces at marine-terminating glaciers. We use three-dimensional direct numerical simulations of a vertical channel with…

Fluid Dynamics · Physics 2023-06-22 Christopher J. Howland , Chong Shen Ng , Roberto Verzicco , Detlef Lohse

Turbulent motions enhance the diffusion of large-scale flows and temperature gradients. Such diffusion is often parameterized by coefficients of turbulent viscosity ($\nu_{\rm t}$) and turbulent thermal diffusivity ($\chi_{\rm t}$) that are…

Fluid Dynamics · Physics 2022-12-07 Petri J. Käpylä , Nishant K. Singh

We investigate the effects of thermal boundary conditions and Mach number on turbulence close to walls. In particular, we study the near-wall asymptotic behavior for adiabatic and pseudo-adiabatic walls, and compare to the asymptotic…

Fluid Dynamics · Physics 2025-04-09 Akanksha Baranwal , Diego A. Donzis , Rodney D. W. Bowersox

We investigate the influence of the Prandtl number ($Pr$) on penetrative internally heated convection (IHC) in both non-rotating and rotating regimes using three-dimensional direct numerical simulations. By varying $Pr$ between 0.1 and 100,…

Fluid Dynamics · Physics 2026-05-14 Rodolfo Ostilla-Mónico , Ali Arslan

The impact of variable material properties, such as temperature-dependent thermal conductivity and dynamical viscosity, on the dynamics of a fully compressible turbulent convection flow beyond the anelastic limit are studied in the present…

Fluid Dynamics · Physics 2024-07-30 John Panickacheril John , Jörg Schumacher

This article shows the importance of flow compressibility on the heat transfer in confined impinging jets, and how it is driven by both the Mach number and the wall heat-flux. Hence, we present a collection of cases at several Mach numbers…

Fluid Dynamics · Physics 2019-11-28 Jose Javier Otero Perez , Richard Sandberg

Despite its importance, there have been few PDE results to investigate Prandtl layers for compressible fluids, in which the thermal boundary layer for the temperature field interacts with the classical velocity Prandtl boundary layer in a…

Analysis of PDEs · Mathematics 2025-09-18 Yan Guo , Yong Wang

Results on the Prandtl-Blasius type kinetic and thermal boundary layer thicknesses in turbulent Rayleigh-B\'enard convection in a broad range of Prandtl numbers are presented. By solving the laminar Prandtl-Blasius boundary layer equations,…

Fluid Dynamics · Physics 2015-03-19 Olga Shishkina , Richard J. A. M. Stevens , Siegfried Grossmann , Detlef Lohse

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 numerical data. As expected, for a flow with $…

Fluid Dynamics · Physics 2021-06-03 Shashwat Bhattacharya , Mahendra K. Verma , Ravi Samtaney

Here, we investigate the linear spatial stability of a parallel two-dimensional compressible boundary layer on an adiabatic plate by considering 2D and 3D disturbances. We employ the Compound Matrix Method for the first time for…

Fluid Dynamics · Physics 2024-01-31 Neha Chaturvedi , Swagata Bhaumik , Rituparn Somvanshi

We investigate the fluctuations of thermodynamic state-variables in compressible aerodynamic wall-turbulence, using results of direct numerical simulation (DNS) of compressible turbulent plane channel flow. The basic transport equations…

Fluid Dynamics · Physics 2016-07-01 G. A. Gerolymos , I. Vallet

We investigate the convective stability of a thin, infinite fluid layer with a rectangular cross-section, subject to imposed heat fluxes at the top and bottom and fixed temperature along the vertical sides. The instability threshold depends…

Statistical properties of turbulent Rayleigh-Benard convection at low Prandtl numbers (Pr), which are typical for liquid metals such as mercury, gallium or liquid sodium, are investigated in high-resolution three-dimensional spectral…

Fluid Dynamics · Physics 2016-09-13 Janet D. Scheel , Joerg Schumacher

Understanding what determines the strength of MHD turbulence in accretion discs is a question of fundamental theoretical and observational importance. In this work we investigate whether the dependence of the turbulent accretion disc stress…

High Energy Astrophysical Phenomena · Physics 2017-10-11 William J. Potter , Steven A. Balbus

Direct numerical simulations of compressible turbulent channel flow at supersonic and hypersonic Mach numbers are performed using a thermally perfect gas model for CO$_2$. The objective is to assess the role of structure-preserving…

Fluid Dynamics · Physics 2026-02-23 Alessandro Aiello , Andrea Palumbo , Carlo De Michele , Gennaro Coppola

The work considers a fully turbulent flow with heat transfer in a channel half-filled with an array of cubes based on the work of Breugem and Boersma (2005) and Chandesris et al. (2013), at $\mathrm{Re}_\mathrm{bulk} = 5485$ and three…

Fluid Dynamics · Physics 2026-05-14 Wojciech Sadowski , Hakan Demir , Francesca di Mare

We perform direct numerical simulations of rotating Rayleigh--B\'enard convection of fluids with low ($Pr=0.1$) and high ($Pr=5$) Prandtl numbers in a horizontally periodic layer with no-slip top and bottom boundaries. At both Prandtl…

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