Abstract
The authors conduct numerical investigations about the three-dimensional thermal convection in a cubic cavity heated below in the gravitational field. Frequency responses are analyzed numerically concerning global quantities such as spatially-averaged kinetic energy and so on. We assume incompressible fluid with a constant Prandtl number Pr=7.1 (water). Tested Rayleigh number Ra is varied from 5.0×10^3 to 8.0×10^4, ω is varied from 10 to 1000. For Ra=1.0×10^4, η is varied from 0.1 to 15. For Ra=4.0×10^4 and 6.0×10^4, the frequency response is investigated for η=0.1. As a result, the authors find out the existence of η that minimizes the maximum frequency response for Ra=1.0×10^4, Pr=7.1.
