The only reference I got is:

O'Rourke,P.J.; Amsden,A.A., "The TAB Method for Numerical Calculation of Spray Droplet Breakup", SAE Technical Paper 872089, 1987.

But I don't have access to this technical paper. There is almost no useful information about TAB method on Internet. Could anybody kindly point me to other papers (or book)?

Thanks.

You should be able to order this paper directly from SAE. Go to their website (www.sae.org) and click on "store", then follow the obvious path. Or, you might try to contact the authors, who work in Group T3 at Los Alamos National Laboratory. Their URL is something like gnarly.lanl.gov. Or you might try to contact Rolf Reitz at www.erc.wisc.edu/index.html since he and his group use the TAB model and have worked on some improvements.

Any "book" on this topic?

Thanks.

[farbfilm]

Hi Zi-Wei Chiou,

if you give me your email-adress, I could send you something about the TAB-Model!

[farbfilm]

Hi,

I have one more question about the TAB-Model. I was looking for the implementation of the model, especially the updating of the droplet size! There, the new radius of the droplet is calculated by

scalar rNew = 0.04*n*rs;

rs is the Sauterradius.

What's the background of this formula? And what is n and where does the factor 0.04 come from??

Can anybody help me???

Cheers, Michael

[senecal]

Hi Michael,

That equation comes from use of the chi-squared drop size distribution. The following steps outline the method:

1. The cumulative distribution function (CDF) is built for the chi-squared distribution - call this cdf(n).

2. When drop breakup is predicted to occur, a random number XX is selected.

3. A loop is done over n. When cdf(n)>XX, the loop is terminated and this value of n is saved.

4. The predicted radius from breakup is then r=0.04*n*smr_tab where smr_tab is the Sauter Mean Radius predicted from the TAB model.

The 0.04 in the above expression comes from the fact that the range on drop size is up to a maximum of 4*smr_tab. The maximum value of n is 100 in this case, and thus the maximum value of r is 0.04*100*smr_tab=4*smr_tab.

I hope this helps.

[farbfilm]

Now it's clear! Thank you so much!!

I guess the maximum size of 4*smr_tab of a droplet is an assumption?!
Is there a reason why a chi-squared distribution is chosen and not any other distribution (like the Rosin-Rammler distribution)?


Thanks, Michael

[senecal]

Hi Michael,

The maximum of 4*smr_tab comes from the following:

1. The CDF is written in terms of Y, where Y=r/rbar. Here r is the drop radius and rbar=(1/3)*smr_tab is the number averaged drop radius.

2. This CDF has a range of 0<Y<12. In other words, CDF(0)=0 and CDF(12) is approximately equal to 1.

3. So the range is 0<Y<12, which is equivalent to 0<r/rbar<12 or 0<r<12*rbar or finally 0<r<4*smr_tab (since smr_tab=3*rbar).

I'm not sure which code you are using. In CONVERGE, we allow for chi-squared or Rosin-Rammler distributions when running the TAB model.

I hope this helps.

[farbfilm]

This helps definitely!! Thank you very much!!!

[huoyinghw]

Hi,foamers
i'm seaching for articles about TAB model ,anyone could help me,i'd appreciate!

[Ahmed]

Originally Posted by Zi-Wei Chiou
;19149

The only reference I got is:

O'Rourke,P.J.; Amsden,A.A., "The TAB Method for Numerical Calculation of Spray Droplet Breakup", SAE Technical Paper 872089, 1987.

But I don't have access to this technical paper. There is almost no useful information about TAB method on Internet. Could anybody kindly point me to other papers (or book)?

Thanks.

check this web pages

http://www.osti.gov/energycitations/...sti_id=5056321
http://www.osti.gov/energycitations/...sti_id=6118786
Library Without Walls Project

[huoyinghw]

thank you very much,Ahmed.

[cfd_anderson]

Hi,

I would like to implement Rosin Rammler Distribution and currently the code i use has Chi-square distribution as explained above. But i need help in implementing the Rosin Rammler Distribution

Thanks

[kk415]

Hello All,

Can anyone through some light on how the Ck (coefficient of stiffness) value is calculated in the TAB model? The original TAB paper by Prof. Reitz says it is obtained by matching the fundamental oscillation frequency. And so Ck is 8.

The fundamental frequency for the spring-mass system -

ω_n=√((C_k σ)/(ρr^3 ))

How Ck is obtained from here??

[tre95]

Dear all,


I just came across this discussion and have a further question on the droplet size distributions computed using the Chi Squared distribution, following the comments of farbflim and senecal.


If I understand correctly, the maximum Sauter Mean Radius r32 for a breakup event is reached for ydot=0, which leads to:
r32/r0=1/(1+(8*K/20))=3/7 with K=10/3


Now, if we allow the maximum radius sampled from Chi Squared to be
r=0.04*n*r32
with n_max=100, then we get
rmax=0.04*100*r32=0.04*100*r0*(3/7)=1.7143*r0


My question is: why would we want to allow the maximum possible radius after breakup to be larger than the radius of the breaking droplet?

[LeBuimi]

I think that the condition in L.209 of TAB.C prevents an increase of the radius of the particles in a parcel in case of breakup:

if (rNew < r) ....