2026/04/30 by Anonymous, Prabakaran Rajamanickam
Earth and Planetary Sciences · Physics and Astronomy · #Geological formations and processes #Seismic Imaging and Inversion Techniques #Seismic Waves and Analysis #physics.flu-dyn
paper · pdf · doi:10.1103/vckp-dcmf
openalex publication_date 2026/07/13 · openalex created_date 2026/07/14 · openalex updated_date 2026/07/30
A recent study [P. Rajamanickam, ] of non-Boussinesq fluids in narrow channels identified a novel shear-induced horizontal buoyancy force that emerges upon depth-averaging the Navier–Stokes equations. This Letter demonstrates that this force is formally equivalent to the divergence of a Korteweg stress tensor. Unlike classical Korteweg stresses, which are typically attributed to molecular-scale cohesive potentials or implemented through assumed constitutive relations, we show that this emergent stress arises purely from self-coupled transport where the internal Ostroumov flow is kinematically coupled to the local density gradient. We derive explicit expressions for the effective stress coefficients, revealing a fundamental dependence on the Prandtl number and Grashof number. This correspondence is contrasted with classical Taylor dispersion, where the absence of self-coupling yields only a uniaxial stress. Although derived within a narrow-channel framework, our results establish a general hydrodynamic template for how quadratic gradient stresses can emerge from subscale, self-coupled flows, such as Marangoni or active-matter flows, offering a continuous transport-driven alternative to molecular mechanisms.