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-   -   Combustion doesnt work correctly (https://www.cfd-online.com/Forums/cfx/213822-combustion-doesnt-work-correctly.html)

LCash January 9, 2019 09:22

Combustion doesnt work correctly
 
3 Attachment(s)
Hello:)


I've got a tutorial for the processing of liquid fuel. For this purpose, drip evaporation and combustion were dealt with. The evaporation was analyzed in a simple pipe with injected kerosene drops ( Inlet ist Air) . I followed the instructions but the Problem is, that no reaction take place. The Kerosene Droplets have to evaporate before it can react.



In the domain i created a Reacting Gas Mixture ( Jet A Air WD1 Reaction/continuous Fluid) und Kerosene ( Jet A liquid/Particle Transport Fluid)


In the Tab Fluid Models -Combustion i select Fluid dependent.

Now the Tab Fluid specific Models:
if i select nothing in the "Combustion tab" for the Reacting Gas Mixture no reaction happend ( in the tutorial its not mentioned) but if i choose finite rate chemistry it will react and the temperature will reach 5000 K ? this is to high or? If i Choose the same diameter (100micron) for the Kerosene Drops it only reaches like 2500 K, but when i select a normal distribution it reaches the 5000-6000K.
I attached the 3 screenshots from the tutorial PDF / normaldistribution/specificDiameter. Why they look so diffrent?
Thank you for your help.


I can send you my files or the Tutorial if oyu want.


Greetings Lucas

ghorrocks January 9, 2019 17:08

Combustion modelling is a complex topic and it is to be expected that challenges will be encountered. To start any new area of study the place to start is a literature review of what previous researchers have done to model this sort of situation previously. Then you will see what sort of models and approaches are required to model this.

Have you done a literature review on your situation yet?

LCash January 11, 2019 10:36

Hey,



it was a previous Bachelor Thesis, and i should use his model to develop the combustion of an Aerospike Nozzle. So i just have the thesis and a few 2D combustions but not especially about ansys cfx


Greetings


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