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-   -   Facing Few Problems in Fluent and Gambit (http://www.cfd-online.com/Forums/fluent/40073-facing-few-problems-fluent-gambit.html)

Ravi Duggirala March 10, 2006 04:35

Facing Few Problems in Fluent and Gambit
 
Hi All,

I have several issues regarding FLUENT and GAMBIT

(1): I created a 3d mesh file (test.msh). Now I am trying to read in Fluent in parallel and when i do the grid check it gave an error at NoSolve ..... I read the same mesh file in fluent (single process; not parallel) and did the grid check, this time i didnt get any error. Is this common while reading a *.msh file ?????

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(2): I created a 3D mesh of 4.85M cells and read in fluent(Single processor; not parallel). I got an error like "zone 9 29374 right handed 452 left handed " The numbers are not exact ( I didnt remember) but I am getting this error like right handed and left handed. Zone 9 in my grid is interior (Fluid)

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Here I have a question regarding perdiodic BC In the figure below: ftp://ftp.eng.auburn.edu/pub/ghugeha/Geom.bmp

I linked (Periodic) Faces MNHD and POGC with N and O as reference vertecies.

Similarly, I linked (Periodic) Faces AEJI and BFKL with E and F as reference vertecies.

I defined the boundary conditions as in the figure. Whilde defining the Periodic BC, I selected Faces MNHD,POGC,AEJI and BFKL and applied Periodic boundary conditions in Gambit.

I meshed and exported to fluent. In the periodic conditions I gave Mass flow rate and initialized and iterated. It gave an error that "AGM solver detected divergence"

I dont know whether periodic boundary conditions work like this or not. If not please help me how to implement periodic conditions in this case. My case is similar to the geometry shown in fig.

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I am trying to generate a 3D grid of 6.0M cell roughly and I cant split the geometry. So I am plannign to create the grid using batch mode. Please give me step by step instructions to run Gambit in batch mode. Also please give a sample Journal file to create a 3D BL mesh followed by volume mesh. I saved the geometry as one dbs file and geometry with meshed edges and few faces attached with BL mesh as another dbs. Please help me in this regard. If you want i can post those tw files in your ftp; please send me the instructions if u want to send thru ftp

SORRY TO LOAD YOU GUYZ WITH SEVERAL ISSUES...

Please any one help me in these regards. Thanks

sumanth March 10, 2006 08:05

Re: Facing Few Problems in Fluent and Gambit
 
hi, you told that in the periodic condition you gave mass flow rate. why did u give is so. if u you want to give mass flow rate then u could have given the mass flow inlet condition. can u clear my confusion. thank u. bye.

Ravi Duggirala March 10, 2006 10:54

Re: Facing Few Problems in Fluent and Gambit
 
Hi, I gave mass flow rate in periodic boundary confition because i dont know the pressure difference and I want the pressure gradient. And also my domain is part of whole domain which repeats. so I gave periodic boundary instead of mass flow inlet.

Thanks Ravi Duggirala

sumanth March 11, 2006 00:41

Re: Facing Few Problems in Fluent and Gambit
 
hi ravi, you said that the ur domain is going to be repeated so u gave the periodic. does ur domain will having samw mass flow conditions at the other periodics. i dont suppose so.

if ur domain gets repeated in the direction perpendicular to ABCD and EFGH planes then u have to consider these planes as the periodic. and u can apply mass flow inlets to the faces of DMNH and AEIJ.

periodic boundary can only be applied when the conditons between the original and periodically place one will be same. if u specify the periodicity in DMNH normal direction the the conditions will not be the same.

just think it over. or may be i misunderstand your problem. it seems u r from andhra. where r u from? all the best.

Ravi Duggirala March 11, 2006 01:48

Re: Facing Few Problems in Fluent and Gambit
 
hi, I guess you misunderstood my problem.... Faces ABFE , EFGH, HGDC, ABCD are symmetric boundary condition. Actually I ran few cases with AEHD and BFGC as periodic BC (no wall in that case) and got expected results... My next step is to consider those walls and i am not able to succeed in that... yeah i am from andhra... basically from Vizag. did B.Tech at GITAM. Waht abt u...

thanks Ravi

sumanth March 11, 2006 04:13

Re: Facing Few Problems in Fluent and Gambit
 
hi, now also i didnot understand urs. because u r saying it should be inlet and at the same time it should be translatory periodic. i am confused. ok i am doing my MTech final sem in psg college, i am from guntur. ok i shell come back to u later. if needed u can mail me bye



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