{"title":"Onset of convection in internally heated, temperature-dependent, power-law viscosity fluids at large viscosity contrasts","authors":"Chhavi Jain, Viatcheslav S. Solomatov","doi":"10.1016/j.pepi.2023.107074","DOIUrl":null,"url":null,"abstract":"<div><p>We use two-dimensional numerical simulations to investigate the finite-amplitude onset of convection in internally heated, infinite Prandtl number fluids with strongly temperature-dependent, power-law viscosity. We focus on the stagnant-lid regime which is relevant to planetary interiors. We find that convection can occur in both the usual, widespread convection planform, where the convection cells form in the entire layer, as well as the localized convection planform characterized by a single upwelling surrounded by a nearly stationary fluid. The critical Rayleigh number for the onset of convection by finite-amplitude perturbations is nearly independent of the convection planform in a broad range of the spacings between upwellings, from of the order of the depth of the layer to up to infinity. A simple heuristic analysis suggests scaling relationships which fit the numerical results in the stagnant-lid regime for an arbitrary power-law exponent, <span><math><mrow><mi>n</mi><mo>></mo><mn>1</mn></mrow></math></span>. The results of this study provide new fluid dynamical constrains on the threshold for convection in planetary interiors.</p></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":null,"pages":null},"PeriodicalIF":2.4000,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics of the Earth and Planetary Interiors","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0031920123001000","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
We use two-dimensional numerical simulations to investigate the finite-amplitude onset of convection in internally heated, infinite Prandtl number fluids with strongly temperature-dependent, power-law viscosity. We focus on the stagnant-lid regime which is relevant to planetary interiors. We find that convection can occur in both the usual, widespread convection planform, where the convection cells form in the entire layer, as well as the localized convection planform characterized by a single upwelling surrounded by a nearly stationary fluid. The critical Rayleigh number for the onset of convection by finite-amplitude perturbations is nearly independent of the convection planform in a broad range of the spacings between upwellings, from of the order of the depth of the layer to up to infinity. A simple heuristic analysis suggests scaling relationships which fit the numerical results in the stagnant-lid regime for an arbitrary power-law exponent, . The results of this study provide new fluid dynamical constrains on the threshold for convection in planetary interiors.
期刊介绍:
Launched in 1968 to fill the need for an international journal in the field of planetary physics, geodesy and geophysics, Physics of the Earth and Planetary Interiors has now grown to become important reading matter for all geophysicists. It is the only journal to be entirely devoted to the physical and chemical processes of planetary interiors.
Original research papers, review articles, short communications and book reviews are all published on a regular basis; and from time to time special issues of the journal are devoted to the publication of the proceedings of symposia and congresses which the editors feel will be of particular interest to the reader.