Hironori Fudeyasu(Faculty of Education and Human Science, Yokohama National University) Ayumi Masuda(Graduate School of Education, Yokohama National University) Naohito Otobe(Faculty of Science, Fukuoka University) Rie Kumazawa((Graduate School of Education, Yokohama National University) Koichi Nishino(Graduate School of Engineering, Yokohama National University)
(Received 3 July,2014; in revised form X October,2014)
The purpose of this study is to construct a method which quantitatively detects the features of baroclinic waves observed in the experiments with a differentially heated rotating fluid annulus. Using the high-interval video frames recorded by a highly sensitive camera located over the annular tank, the Particle Image Velocimetry (PIV) provides the high-resolution digital data to capture the surface flow pattern in the experiments. The numeric data provided by the PIV is used to calculate the kinetic energy, and then divide into the annual mean of kinetic energy (MKE) from axi-symmetric flow and eddy kinetic energy (EKE) from asymmetric flow. Furthermore, the each wave-number component of EKE is estimated from the each wave-number component in the asymmetric flow.
In order to validate the method, we apply the method to the results from three experiments. From the result of experiment in which the symmetric-flow pattern is distinct, the analysis showed that MKE is dominant. On the other hand, in the case of a steady-baroclinic-waves flow, the particular wave-number EKE is dominant and the side-band-component EKE is neglected. In the case of the non-steady flow pattern, the side-band-component EKE is comparable to the particular wave-number EKE. Namely the multiple wave-number flow patterns are overlapped. It is expected that the method developed in this study could provide new and useful insights into the experiments with a differentially heated rotating fluid annulus.