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-   -   Numeca Fine/Hexa simulation of catalytic converter (https://www.cfd-online.com/Forums/numeca/74869-numeca-fine-hexa-simulation-catalytic-converter.html)

 jackr84 April 10, 2010 07:43

Numeca Fine/Hexa simulation of catalytic converter

Hi, I don't find user guide or tutorial of Numeca Fine/Hexa, for this reason I'm tring to know parameter's definition in the Boundary Condition and Initial solution, exactly:
What do it means "reference parameters" in the section "Flow model Parameters"?
How do i do to initialize the solution with costant values? My boundary condition are:
mass flow rate=0,125 kg/s, pressure outlet 90211 Pa, ambient pressure 98350 Pa, and i have a porous media where the inertial and viscous resistance I determinated with Ergun equation.

 Hamidzoka April 11, 2010 23:17

Dear jack;
"reference parameters" are applied to calculate some variables like entropy. for example when calculating delta entropy you need reference pressure and temperature. "reference parameters" are usually set to ambient conditions and the solution is not sensitive to them.

in order to initialize the solution, put all mesh blocks into a group. then choose the constant values icon. you had better to set the initial pressure larger than outlet in order to facilitate the flow through the medium in its corrct direction.

for tutorials, i 've sent a link for you and then explained how you can download files. but unfortunately these posts were omitted by the site manager and i was punished since it was a crackers site.

regards

 jackr84 April 12, 2010 11:50

In the boundary condition if i put the mass flow rate what does direction vector represnt? I have a pressure outlet 0f 90211 Pa, what do i put in the outlet?And then, to initialize the problem, what do paramater set?

 Hamidzoka April 13, 2010 22:50

direction vector defines the direction of velocity vector entering the domain. for example if inlet flow is along the z-axis, you should easily enter 0,0,1 for x,y,z respectively.
for the output, set the 90211 as the outlet pressure. in outlet tab, select "pressure imposed". then select "averaged static pressure".
in order to initialize the problem, select "constant value" and then enter initial tempreture, pressure and velocity.

regards

 jackr84 April 14, 2010 01:38

The fluid filed is not aligned with nothing axis!!!!The veocity components are:
Vx=-17,16
Vy=-19,16;
Vz=44,96

 Hamidzoka April 14, 2010 03:41

it is just a basic concept.
calculate Vtotal magnitude easily as the following:
Vtotal=(Vx^2+Vy^2+Vz^2)^0.5
then:
x direction= Vx/Vtot
y direction= Vy/Vtot
z direction= Vz/Vtot

regards

 jackr84 April 14, 2010 06:41

I did all that you said me but the errore is alway the same:
flow solver error

 Hamidzoka April 15, 2010 03:07

did you define all boundries? is there any undefined boundary in your domain?
if you have a valid domain and defined boundaries, your problem is concerned with solver adjustments

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