Exploring Convection in the Vicinity of Localized Decreases in Thermal Diffusivity
Session Number
PHYS 32
Advisor(s)
Liam Oā€™Connor, Northwestern University, Center for Interdisciplinary Research in Astrophysics
Discipline
Physical Science
Start Date
17-4-2024 10:25 AM
End Date
17-4-2024 10:40 AM
Abstract
Context: Computational convection simulations are a critical tool for understanding the dynamics of a variety of different environments; including the complex interiors of stars. Methods Direct-Numerical-Simulations of Rayleigh-Bernard convection are performed within a periodic rectangular domain. A localized decrease in thermal diffusivity (š¯›¼š¯›¼) is imparted within the domain at a certain temperature, with a parameterized amplitude (A) of decrease. Runs are performed at a constant Prandtl number (Pr = 1), and aspect ratio (ā²„ = 4). Simulations are run within a comprehensive set of amplitudes between A = 0.3 and A = 0.9, and at Rayleigh numbers between Ra = 10 6 and Ra = 10 7 . The vertical heat fluxes of the system, along with globally- averaged Reynolds and Nusselt numbers are also collected as a measure of turbulence and convective efficiency.
Results: The convective heat flux showed significant differences between the nominal (A = 0) and decreased cases (0
Discussion: The lack of significant change in for the majority of amplitudes indicates a conservation of convective efficiency in the vicinity of decreases in thermal diffusivity. The work gathered here has far reaching implications on astrophysical systems such as variable stars.
Results The convective heat flux showed significant differences between the nominal (A = 0) and decreased cases (07.
Discussion The lack of significant change in for the majority of amplitudes indicates a conservation of convective efficiency in the vicinity of decreases in thermal diffusivity. The work gathered here has far-reaching implications on astrophysical systems such as variable stars.
Exploring Convection in the Vicinity of Localized Decreases in Thermal Diffusivity
Context: Computational convection simulations are a critical tool for understanding the dynamics of a variety of different environments; including the complex interiors of stars. Methods Direct-Numerical-Simulations of Rayleigh-Bernard convection are performed within a periodic rectangular domain. A localized decrease in thermal diffusivity (š¯›¼š¯›¼) is imparted within the domain at a certain temperature, with a parameterized amplitude (A) of decrease. Runs are performed at a constant Prandtl number (Pr = 1), and aspect ratio (ā²„ = 4). Simulations are run within a comprehensive set of amplitudes between A = 0.3 and A = 0.9, and at Rayleigh numbers between Ra = 10 6 and Ra = 10 7 . The vertical heat fluxes of the system, along with globally- averaged Reynolds and Nusselt numbers are also collected as a measure of turbulence and convective efficiency.
Results: The convective heat flux showed significant differences between the nominal (A = 0) and decreased cases (0
Discussion: The lack of significant change in for the majority of amplitudes indicates a conservation of convective efficiency in the vicinity of decreases in thermal diffusivity. The work gathered here has far reaching implications on astrophysical systems such as variable stars.
Results The convective heat flux showed significant differences between the nominal (A = 0) and decreased cases (07.
Discussion The lack of significant change in for the majority of amplitudes indicates a conservation of convective efficiency in the vicinity of decreases in thermal diffusivity. The work gathered here has far-reaching implications on astrophysical systems such as variable stars.