抄録
This paper investigates the transition frequencies of acoustically couplet gas bubbles by employing a direct numerical simulation technique which is an improved variant of the CIP-CUP method. Recent theoretical studies by the present author showed that gas bubbles interacting in an acoustic field have an undiscovered characteristic frequency, named "transition frequency", which reverses the pulsation phases of bubbles without causing resonance response. In more recent study, it was shown that this characteristic frequency might play an important role in the sign reversal of the secondary Bjerknes force which sometimes result in a stable structure formation of bubbles in an acoustic field. The numerical results presented in this paper have demonstrated that the characteristic frequency indeed exists.
