- #1
rwooduk
- 762
- 59
Hi,
I am trying to distinguish the mechanisms for acoustic and quasi acoustic streaming during cavitation.
This is what I have written so far:
I have the quasi acoustic streaming pretty much sorted, it's just as a result of macroscopic applied frequency effects (flow) from the transducer. Its the acoustic streaming I'm struggling with! Is it like I have written above a direct result of bubble surface fluctuations?
For example for a bubble near a surface we have a boundary streaming effect with causes the bubble to collapse at the surface, which is a direct result of asymmetry of flow near the surface... BUT what is the assymetry of flow due to? The oscillations of the bubble?
I'm trying to figure out what exactly is causing this streaming in a cavitational environment.
Thanks for any ideas!
I am trying to distinguish the mechanisms for acoustic and quasi acoustic streaming during cavitation.
This is what I have written so far:
Quasi acoustic streaming may be described as being due to the existence of an energy gradient in the direction of propagation of the sound field, thus a macroscopic (accelerating) flow develops in its direction.
Acoustic streaming, although inducing some flow, can be said to be a localised phenomenon near to the individual bubbles due to the thermal and mass concentration gradient at the bubbles surface and consequent transfer of the bubbles constituents to the fluid
Quasi acoustic streaming that tends to occur at higher frequencies and acoustic streaming that can occur at both low and high frequencies but has more of an influence at higher powers.
I have the quasi acoustic streaming pretty much sorted, it's just as a result of macroscopic applied frequency effects (flow) from the transducer. Its the acoustic streaming I'm struggling with! Is it like I have written above a direct result of bubble surface fluctuations?
For example for a bubble near a surface we have a boundary streaming effect with causes the bubble to collapse at the surface, which is a direct result of asymmetry of flow near the surface... BUT what is the assymetry of flow due to? The oscillations of the bubble?
I'm trying to figure out what exactly is causing this streaming in a cavitational environment.
Thanks for any ideas!