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Related papers: Transition to branching flows in optimal planar co…

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We compute steady planar incompressible flows and wall shapes that maximize the rate of heat transfer (Nu) between and hot and cold walls, for a given rate of viscous dissipation by the flow (Pe$^2$). In the case of no flow, we show…

Fluid Dynamics · Physics 2023-09-29 Silas Alben

We find steady channel flows that are locally optimal for transferring heat from fixed-temperature walls, under the constraint of a fixed rate of viscous dissipation (enstrophy = $Pe^2$), also the power needed to pump the fluid through the…

Fluid Dynamics · Physics 2017-05-12 Silas Alben

We compute incompressible two-dimensional fluid flows that maximize the rate of heat transfer from the walls of a straight channel given a specified flow input power $Pe^{2}$, where $Pe$ is the P\'{e}clet number. We use the…

Fluid Dynamics · Physics 2025-07-15 Shivani Prabala , Silas Alben

Gradient ascent methods are developed to compute incompressible flows that maximize heat transport between two isothermal no-slip parallel walls. Parameterizing the magnitude of velocity fields by a P\'eclet number $\text{Pe}$ proportional…

Fluid Dynamics · Physics 2020-04-13 Andre N. Souza , Ian Tobasco , Charles R. Doering

We consider the problem of optimizing heat transport through an incompressible fluid layer. Modeling passive scalar transport by advection-diffusion, we maximize the mean rate of total transport by a divergence-free velocity field. Subject…

Analysis of PDEs · Mathematics 2019-09-18 Charles R. Doering , Ian Tobasco

Motivated by the search for sharp bounds on turbulent heat transfer as well as the design of optimal heat exchangers, we consider incompressible flows that most efficiently cool an internally heated disc. Heat enters via a distributed…

Analysis of PDEs · Mathematics 2022-05-26 Ian Tobasco

The vertical heated-pipe is widely used in thermal engineering applications, as buoyancy can help drive a flow, but several flow regimes are possible: shear-driven turbulence, laminarised flow, and convective turbulence. Steady velocity…

Fluid Dynamics · Physics 2025-09-24 Shijun Chu , Elena Marensi , Ashley P. Willis

Steady flows that optimize heat transport are obtained for two-dimensional Rayleigh-B\'enard convection with no-slip horizontal walls for a variety of Prandtl numbers $Pr$ and Rayleigh number up to $Ra\sim 10^9$. Power law scalings of…

Fluid Dynamics · Physics 2023-07-19 David Sondak , Leslie M. Smith , Fabian Waleffe

The divergence-free time-independent velocity vector field has been determined so as to maximise heat transfer between two parallel plates of a constant temperature difference under the constraint of fixed total enstrophy. The present…

Fluid Dynamics · Physics 2018-08-03 Shingo Motoki , Genta Kawahara , Masaki Shimizu

We consider stability of steady convective flows in a horizontal layer with stress-free boundaries, heated below and rotating about the vertical axis, in the Boussinesq approximation (the Rayleigh-Benard convection). The flows under…

Fluid Dynamics · Physics 2015-06-26 O. M. Podvigina

We determine unsteady flow perturbations that are optimal for enhancing the rate of heat transfer between hot and cold walls (i.e. the Nusselt number Nu), under the constraint of fixed flow power (Pe$^2$, where Pe is the P\'{e}clet number).…

Fluid Dynamics · Physics 2026-01-14 Silas Alben , Xiaojia Wang , Nicole Vuong

Internally heated convection involves the transfer of heat by fluid motion between a distribution of sources and sinks. Focusing on the balanced case where the total heat added by the sources matches the heat taken away by the sinks, we…

Analysis of PDEs · Mathematics 2022-12-13 Binglin Song , Giovanni Fantuzzi , Ian Tobasco

A heat exchanger can be modeled as a closed domain containing an incompressible fluid. The moving fluid has a temperature distribution obeying the advection-diffusion equation, with zero temperature boundary conditions at the walls.…

Fluid Dynamics · Physics 2018-02-23 Florence Marcotte , Charles R. Doering , Jean-Luc Thiffeault , William R. Young

We perform direct numerical simulations of wall sheared Rayleigh-B\'enard (RB) convection for Rayleigh numbers up to $Ra=10^8$, Prandtl number unity, and wall shear Reynolds numbers up to $Re_w=10000$. Using the Monin-Obukhov length…

We generalize a recent method for computing optimal 2D convection cooling flows in a horizontal layer to a wide range of geometries, including those relevant for technological applications. We write the problem in a conformal pair of…

Fluid Dynamics · Physics 2017-04-05 Silas Alben

We compute unsteady perturbations that optimally increase the heat transfer (Nu) of optimal steady unidirectional channel flows, for a given average rate of power consumption Pe$^2$. The perturbations are expanded in a basis of modes, and…

Fluid Dynamics · Physics 2024-09-24 Silas Alben , Shivani Prabala , Mitchell Godek

In this paper, we have used the QUICK scheme of the finite volume method to investigate the problem of steady 2-D free convective incompressible flow with heat and mass transfer in an inclined rectangular domain at different Rayleigh…

Fluid Dynamics · Physics 2017-08-28 V. Ambethkar , D. Kushawaha

Direct numerical simulations have been performed for heat and momentum transfer in internally heated turbulent shear flow with constant bulk mean velocity and temperature, $u_{b}$ and $\theta_{b}$, between parallel, isothermal, no-slip and…

Fluid Dynamics · Physics 2023-06-22 Shingo Motoki , Kentaro Tsugawa , Masaki Shimizu , Genta Kawahara

We discuss what is an optimal velocity field for more heat transfer and less energy dissipation under the constraints of the continuity equation for the velocity and the advection-diffusion equation for temperature in plane Couette flow.…

Fluid Dynamics · Physics 2018-02-14 Shingo Motoki , Genta Kawahara , Masaki Shimizu

In stars and planets natural processes heat convective flows in the bulk of a convective region rather than at hard boundaries. By characterizing how convective dynamics are determined by the strength of an internal heating source we can…

Fluid Dynamics · Physics 2024-04-16 Whitney T. Powers , Evan H. Anders , Benjamin P. Brown
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