Role of boundary conditions and volumetric heating in electrothermal anisotropic porous convection

Role of boundary conditions and volumetric heating in electrothermal anisotropic porous convection | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Role of boundary conditions and volumetric heating in electrothermal anisotropic porous convection C S Rachitha, C. E. Nanjundappa, I. S. Shivakumara This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6994779/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 16 Feb, 2026 Read the published version in Microgravity Science and Technology → Version 1 posted 11 You are reading this latest preprint version Abstract This study presents a theoretical investigation into the linear instability of electrothermal convection in an internally heated, anisotropic dielectric fluid-saturated porous layer, modeled by the Darcy-Brinkman equation and subjected to an AC electric field. The porous medium exhibits anisotropy in both permeability and thermal diffusivity, with isotropy assumed in the horizontal plane. The vertical permeability is fixed at twice the horizontal value, while thermal diffusivity anisotropy is treated as a free parameter. The layer is bounded above and below by isothermal surfaces, which may be rigid or stress-free, with appropriate electric potential boundary conditions imposed. The principle of exchange of stabilities is shown to hold, and the resulting linear eigenvalue problem is solved using Galerkin’s method of weighted residuals for free-free (F–F), rigid-rigid (R–R), and mixed (R-F) boundary conditions. The analysis reveals that increasing the AC electric Rayleigh number, Darcy number, and internal heat generation promotes the onset of convection, whereas enhanced thermal anisotropy suppresses it. Importantly, the qualitative nature of the stability characteristics is preserved across all velocity boundary combinations. Besides, electroconvection without gravity is analyzed to isolate the role of electric forces, and the behavior is found to mirror that seen with gravitational forces. AC electric field dielectric fluid anisotropy porous medium volumetric internal heating weighted residuals technique Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 16 Feb, 2026 Read the published version in Microgravity Science and Technology → Version 1 posted Editorial decision: Revision requested 05 Oct, 2025 Reviews received at journal 05 Oct, 2025 Reviewers agreed at journal 30 Aug, 2025 Reviews received at journal 12 Aug, 2025 Reviews received at journal 11 Aug, 2025 Reviewers agreed at journal 22 Jul, 2025 Reviewers agreed at journal 22 Jul, 2025 Reviewers invited by journal 15 Jul, 2025 Editor assigned by journal 07 Jul, 2025 Submission checks completed at journal 07 Jul, 2025 First submitted to journal 27 Jun, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6994779","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":486105287,"identity":"7880fe9e-9934-4ff6-aecd-3c5d527acadf","order_by":0,"name":"C S Rachitha","email":"","orcid":"","institution":"Dr. Ambedkar Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"C","middleName":"S","lastName":"Rachitha","suffix":""},{"id":486105288,"identity":"f8612c48-919a-4841-9caa-0266697469ce","order_by":1,"name":"C. E. 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