[anirudh1]

Hello,
I would like to know whether converge v2.4 version takes film evaporation into account when you use wall-film model in spray modelling ?

In my case the film mass in film.out is staying same throughout the compression stroke, even though temperature is rising and reached 950K at the end of stroke . Iam using DIESEL2 as fuel and early injection inside cylinder.

What can be done to solve this issue. Is there any film evaporation option in v2.4. Kindly help.

Thanks and regards
Anirudh

[azandian]

Hi Anirudh,

Yes, film evaporation is taken into account in CONVERGE-2.4 if the evaporation model is turned on. Unlike v3.0 the film and spray evaporation are not controlled separately in v2.4. So, regardless of the wall-film model, make sure you activate the evaporation model in the spray modeling window.

As for what you are seeing in your case, notice that the temperature you are seeing in the cylinder is the average temperature throught the cylinder region. This temperature might be lower near the walls. Also, for film evaporation, the film temperature is taken to be the average of the wall temperature and the temperature in the first cell attached to the wall boundary. So, even if your cell temperature is 950 K, if your wall temperature is 450 K, the code will average these and take the film temperature to be 700 K.

To better analyze your case, turn on the wall output option in the Output files panel - select Boundaries and Stress. This will generate boundary outputs for each wall. Among the outputed data are the min, max and average of the wall temperature, near wall temperature as well as the wall heat transfer rate. You can get a better understanding of the film temperature after looking at these output values.

You can also take a look at your postfiles - make sure you select temperature and film flag for your parcel variables - to see where your film parcels are located and what temperature they have.