The velocity and temperature distributions are measured for natural convection in a horizontal concentric annulus at high Rayleigh numbers with using a hot-wire anemometer and a thermocouple. Dealing with these data statistically, the average velocity and temperature profiles as well as their turbulence quantities are obtained. By carrying out the spectrum analysis of these velocity fluctuations, a transition from the laminar natural convection to the turbulent one is clarified. With increasing Rayleigh number, the stable flow pattern becomes unstable to a periodic one. The periodicity diminishes when the Rayleigh number is further increased. A comparison of these experimental data with the time-dependent three-dimensional numerical results, which were reported in our previous paper, shows a good agreement.
|Number of pages||9|
|Journal||Journal of the Atomic Energy Society of Japan / Atomic Energy Society of Japan|
|Publication status||Published - 1988|
All Science Journal Classification (ASJC) codes
- Nuclear Energy and Engineering