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Researchers propose mechanism for heat-transfer enhancement in convective turbulence

Researchers propose mechanism for heat-transfer enhancement in convective turbulence

Posted Date: 2023-07-25
Researchers propose mechanism for heat-transfer enhancement in convective turbulence
(a) The Nusselt quantity ratio Nu/NuRB and (b) the Reynolds quantity ratio Re/ReRB versus the wave quantity kH, respectively. In (a) and (b), totally different symbols characterize totally different combos of (Ra, A/H) as indicated within the legend of (a). (c) The viscous and thermal boundary-layer thicknesses versus the Rayleigh quantity for the RB move. Credit score: Bodily Assessment Letters (2023). DOI: 10.1103/PhysRevLett.130.204001

Researchers from the Division of Mechanics and Engineering Science at Peking College (PKU), led by Prof. Chen Shiyi and Prof. Yang Yantao, have just lately proposed a mechanism to boost the effectivity of warmth switch in convective turbulence. The paper has been printed in Bodily Assessment Letters, entitled “Boundary-Layer Disruption and Warmth-Switch Enhancement in Convection Turbulence by Oscillating Deformations of Boundary.”

Convective turbulence, pushed by gravity-induced instabilities ensuing from temperature gradients, is a prevalent incidence in varied pure flows, together with the environment, ocean, and mantle. It's known as an indispensable course of for each warmth and mass transport and finds sensible functions in warmth dissipation in units and indoor temperature management.

Nevertheless, the prevailing strategies for regulating convective turbulence endure from a number of drawbacks. They solely perform in a restricted vary of parameters, demand an especially excessive frequency, and consequently, the general warmth switch enhancement is restricted.

The PKU analysis staff’s novel strategy focuses on introducing oscillating deformations within the type of standing waves in a move system the place the highest is at a excessive temperature and the underside at a low temperature, thus successfully modulating transport effectivity.

The analysis outcomes show that vital will increase in warmth flux may be achieved solely when the amplitude of boundary oscillation approaches the thickness of the boundary layers. Notably, the dimensionless warmth flux greater than doubles when the dimensionless frequency exactly reaches 8. In essence, oscillating deformations of boundary can break the bottleneck of traditional thermal convection within the boundary layer and open a brand new venue for modulating the convection turbulence.

Supplied by Peking College