Outputs (80)

Discontinuity waves in temperature and diffusion models (2024)
Journal Article
Ciarletta, M., Straughan, B., & Tibullo, V. (2024). Discontinuity waves in temperature and diffusion models. Mechanics Research Communications, 137, Article 104274. https://doi.org/10.1016/j.mechrescom.2024.104274

We analyse shock wave behaviour in a hyperbolic diffusion system with a general forcing term which is qualitatively not dissimilar to a logistic growth term. The amplitude behaviour is interesting and depends critically on a parameter in the forcing... Read More about Discontinuity waves in temperature and diffusion models.

Asymptotic behaviour for convection with anomalous diffusion (2024)
Journal Article
Straughan, B., & Barletta, A. (2024). Asymptotic behaviour for convection with anomalous diffusion. Continuum Mechanics and Thermodynamics, https://doi.org/10.1007/s00161-024-01291-7

We investigate the fully nonlinear model for convection in a Darcy porous material where the diffusion is of anomalous type as recently proposed by Barletta. The fully nonlinear model is analysed but we allow for variable gravity or penetrative conve... Read More about Asymptotic behaviour for convection with anomalous diffusion.

Thermal convection with a Cattaneo heat flux model (2024)
Journal Article
Gentile, M., & Straughan, B. (2024). Thermal convection with a Cattaneo heat flux model. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 480(2282), Article 20230771. https://doi.org/10.1098/rspa.2023.0771

The problem of thermal convection in a layer of viscous incompressible fluid is analysed. The heat flux law is taken to be one of Cattaneo type. The time derivative of the heat flux is allowed to be a material derivative, or a general objective deriv... Read More about Thermal convection with a Cattaneo heat flux model.

Sharp Instability Estimates for Bidisperse Convection with Local Thermal Non-equilibrium (2023)
Journal Article
Franchi, F., Nibbi, R., & Straughan, B. (2024). Sharp Instability Estimates for Bidisperse Convection with Local Thermal Non-equilibrium. Transport in Porous Media, 151(1), 193-211. https://doi.org/10.1007/s11242-023-02038-9

We analyse a theory for thermal convection in a Darcy porous material where the skeletal structure is one with macropores, but also cracks or fissures, giving rise to a series of micropores. This is thus thermal convection in a bidisperse, or double... Read More about Sharp Instability Estimates for Bidisperse Convection with Local Thermal Non-equilibrium.

Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time (2023)
Journal Article
Gentile, M., & Straughan, B. (2023). Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time. Acta Mechanica, 234(9), 4001-4009. https://doi.org/10.1007/s00707-023-03592-5

The final value value problem for the Brinkman–Forchheimer–Kelvin–Voigt equations is analysed for quadratic and cubic types of Forchheimer nonlinearity. The main term in the Forchheimer equations is allowed to be fully anisotropic. It is shown that t... Read More about Stabilization estimates for the Brinkman–Forchheimer–Kelvin–Voigt equation backward in time.

Effect of Temperature Upon Double Diffusive Instability in Navier–Stokes–Voigt Models with Kazhikhov–Smagulov and Korteweg Terms (2023)
Journal Article
Straughan, B. (2023). Effect of Temperature Upon Double Diffusive Instability in Navier–Stokes–Voigt Models with Kazhikhov–Smagulov and Korteweg Terms. Applied Mathematics and Optimization, 87(54), Article 54. https://doi.org/10.1007/s00245-023-09964-6

We present models for convection in a mixture of viscous fluids when the layer is heated from below and simultaneously the pointwise volume concentration of one of the fluids is heavier below. This configuration produces a problem of competitive doub... Read More about Effect of Temperature Upon Double Diffusive Instability in Navier–Stokes–Voigt Models with Kazhikhov–Smagulov and Korteweg Terms.

Thermal convection in a higher-gradient Navier–Stokes fluid (2023)
Journal Article
Straughan, B. (2023). Thermal convection in a higher-gradient Navier–Stokes fluid. European Physical Journal Plus, 138(60), https://doi.org/10.1140/epjp/s13360-023-03658-2

We discuss models for flow in a class of generalized Navier–Stokes equations. The work concentrates on producing models for thermal convection, analysing these in detail, and deriving critical Rayleigh and wave numbers for the onset of convective flu... Read More about Thermal convection in a higher-gradient Navier–Stokes fluid.

Thermal convection in a Brinkman–Darcy–Kelvin–Voigt fluid with a generalized Maxwell–Cattaneo law (2022)
Journal Article
Straughan, B. (2023). Thermal convection in a Brinkman–Darcy–Kelvin–Voigt fluid with a generalized Maxwell–Cattaneo law. Annali dell'Universita di Ferrara, 69, 521–540. https://doi.org/10.1007/s11565-022-00448-z

We investigate thoroughly a model for thermal convection of a class of viscoelastic fluids in a porous medium of Brinkman–Darcy type. The saturating fluids are of Kelvin–Voigt nature. The equations governing the temperature field arise from Maxwell–C... Read More about Thermal convection in a Brinkman–Darcy–Kelvin–Voigt fluid with a generalized Maxwell–Cattaneo law.

Effect of anisotropy and boundary conditions on Darcy and Brinkman porous penetrative convection (2022)
Journal Article
Straughan, B. (2022). Effect of anisotropy and boundary conditions on Darcy and Brinkman porous penetrative convection. Environmental Fluid Mechanics, https://doi.org/10.1007/s10652-022-09888-9

We investigate the effects of anisotropic permeability and changing boundary conditions upon the onset of penetrative convection in a porous medium of Darcy type and of Brinkman type. Attention is focussed on the critical eigenfunctions which show ho... Read More about Effect of anisotropy and boundary conditions on Darcy and Brinkman porous penetrative convection.

Thermal convection with generalized friction (2021)
Journal Article
Straughan, B. (2022). Thermal convection with generalized friction. Annali dell'Universita di Ferrara, 68(1), 63-68. https://doi.org/10.1007/s11565-021-00382-6

A model for thermal convection with generalized friction is investigated. It is shown that the linear instability threshold is the same as the global stability one. In addition, decay of the energy in the L2 norm is shown for the perturbation velocit... Read More about Thermal convection with generalized friction.