Learning Forum

[Nicolo]

Hi,

I am trying to simulate in ANSYS fluent 2020 R1, and I need to use formic acid from the ANSYS fluent database, but it seems to me that this material does not have the right values (density 1 kg/m3 and viscosity 1.72e-5). I have uploaded the picture.

I also noticed that these values are reported for a large group of materials as well!!

So given that my simulation is a two phase flow of formic acid and CO2 and there is not heat exchange involved, can I simply change the values in the box in fluent database and continue or I should write a new entry (and if so, please let me know how I should do it?)

Thanks in advance

 

[Rob]

You'll need to find data for those. Looking at the full entry it looks like it's intended to use a model to calculate density & viscosity as the molecular weight etc are there. 

[Nicolo]

Thanks Rwoolhou for the reply.

So at this stage are you suggesting that I enter the value of density and viscosity manually from literature or choose a method like in picture (it also never asked me for a model for viscosity or to enter the viscosity manually after I chose the model for density.

If I have to choose a method it would be great if you could give me suggestion on wich model I use?

thanks in advance

 

[Rob]

It depends. Given you're asking me I'd suggest finding a constant value in literature and use that. The alternatives are a lot more advanced and not something I'd try as a new user.