[OK_FDR]

Good afternoon.
My supervisor set the task to calculate the FTF.
I understood what this addiction means, but there was a problem.
They enter into the formula for calculation G=(Q'rms/Qmean)/(V'rms/Vmean), and in all literature it is written that this is a heat release(Q), experimental dependencies and calculated are also given, but it is not written how to calculate this value using Ansys. I found the value of the Product Formation Rate, but I don’t know how to use it.

I have fluent 18.2. I will accept any help. A link to an article or book or any other material that I could use.
Hope to be heard)
Thanks.

[LuckyTran]

The heat release is roughly the product formation rate multiplied by the heating value. But there are way more accurate ways of estimating it. It depends on how accurately you want to calculate it. It also depends on your combustion model. There are some challenges to defining what exactly is heat release because of all the different ways energy can be transferred.

However, all you care about is Q'rms/Qmean, which could just as easily approximated by the rms and mean of the product formation rate if the thermochemistry is the same everywhere in your domain. So you don't actually need the heat release if you're only interested in the FTF.

[OK_FDR]

Many thanks.
I implement this approach on a mathematical model that was taken from an article (Xingsi Han, Jingxuan Li, Aimee S. Morgans, 2015).
I was given the task of comparing the value of the parameter G = (Q'rms / Qmean) / (V'rms / Vmean) from the article and what I get in my calculation.
1) And here I have a big question. The values ​​in the numerator are the values ​​(PFR'rms / PFRmean) to get it, do I have to average it over the volume of the entire model or don’t understand some local area?

[OK_FDR]

the article states that these parameters are taken at the entrance to the domain.

[OK_FDR]

Originally Posted by LuckyTran

The heat release is roughly the product formation rate multiplied by the heating value. But there are way more accurate ways of estimating it. It depends on how accurately you want to calculate it. It also depends on your combustion model. There are some challenges to defining what exactly is heat release because of all the different ways energy can be transferred.

However, all you care about is Q'rms/Qmean, which could just as easily approximated by the rms and mean of the product formation rate if the thermochemistry is the same everywhere in your domain. So you don't actually need the heat release if you're only interested in the FTF.

What more accurate methods are you talking about?
I am using Partially Premixed Combustion model (FGM) (Sandiego mechanism).

[jimmy_chan]

Hi, can you please tell me how do you calculate the heat release rate(or define the custom field function) in fluent? I'm also trapped in this problem ,can you give me some advice?