An Experimental Study on Chaotic Behavior of Thermohydraulic Oscillation in an Evaporating Tube

The characteristics of flow oscillations in density wave instabilities are experimentally investigated by means of the deterministic manner based on chaotic dynamics. The results are as follows. ( 1 ) The least number of significant figures of the time-series data is two, but it is plausible to take more than three if possible. ( 2 ) The flow oscillation analyzed in this paper is chaotic and obeys a dynamics with a small degree of freedom. ( 3 ) Given the mass flux, the dimension of the attractor in the unstable region decreases with the heat flux, which means that the randomness of the dynamics gradually attenuates with departure from the stability threshold and the structure of the attractor becomes simpler. ( 4 ) The dimension of the attractor can be related to the fundamental frequency, which means that the characteristics of the chaotic dynamics generating the density wave instability depend mainly on the fundamental frequency in the flow oscillation independent of the differences in the experimental conditions.