An numerical analysis has been performed on unsteady three-dimensional natural convection in a concentric horizontal annulus filled with air. The explicit leap-frog scheme is used for integrating three-dimensional time-dependent equations and the fast Fourier transform (FFT) for solving the Poisson equations for pressure. An oscillatory flow is found to occur at high Rayleigh numbers, which agree qualitatively with the experimental observation made by Bishop et al. An experiment is also conducted to measure temperature fluctuations; a comparison between periods of fluctuations obtained numerically and experimentally shows a good agreement. Numerical calculations yield various statistical parameters of turbulence at higher Rayleigh numbers, which wait experimental verifications, however.
|Number of pages||10|
|Journal||Nippon Genshiryoku Gakkaishi/Journal of the Atomic Energy Society of Japan|
|Publication status||Published - 1988|
All Science Journal Classification (ASJC) codes
- Nuclear Energy and Engineering