13
$\begingroup$

I am investigating the effects of bubble oscillations (calculated using the Rayleigh-Plesset equation for bubble dynamics) on the turbulence in two-phase flows. Since I am using cryogenic fluids, the thermal effects also play a role. I am trying to find out the connection between the oscillation frequencies and how they influence the turbulence dissipation rate.

I guess that, when the frequencies are high, i.e., when the liquid-vapour interface oscillates at high frequencies, the turbulent kinetic energy in the flow increases. So, will the dissipation rate also increase proportionally to the turbulent kinetic energy? (epsilon proportional to k^1.5)

$\endgroup$
1
  • 3
    $\begingroup$ This is a highly complex academic problem. I'm guessing this is a (hopefully graduate) research topic? While it's not off-topic, I highly doubt this question will attract a complete and satisfying answer. $\endgroup$ Commented May 19, 2017 at 16:06

2 Answers 2

0
$\begingroup$

I remember doing something alike but with solids in oil pipes... As it turns out in a quick search in google I found the thesis is now published online by Arizona State University.

The oscillation is given in this model by a WENO equation even though the meaning of WENO is Weighted Essentially Non Oscillatory.

So the idea is this, you divide the pipe system in many small cells in three levels, the last level is defined to be either one phase or the other. Here comes the interesting part; The G(x) parameter (can't remember the name but it is on the documentation for sure) is defined to solve the interphase.

If you have any trouble compiling the software I would gladly help, I had to debug some of it as part of my social services.

https://repository.asu.edu/items/34792

$\endgroup$
0
$\begingroup$

An interesting question

" I am trying to find out the connection between the oscillation frequencies and how they influence the turbulence dissipation rate."

I'm not familiar with bubble mechanics, but all materials that can conduct a mechanical wave (sound) have three important properties: the speed of the wave, acoustic dampening, and compressibility, the more dense a material is (down to a limit) speed increase (and therefore the frequency gets lower), this is also highly dependent on the temperature (compressibility and energy already present in the material), a bubble in a cryogenic fluid would get a slower speed and a much higher frequency than expected. The fluid would also have very different acoustic dampening as a fluid or gas. In a gas phase its a lot higher, so the wave exiting the bubble (not taking reflected energy into account) would be lower hitting the next in any vector. Dampening is also frequency and temperature dependent. Just some thoughts.

I hope this helps in some way.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.