[luna]

I have worked on Evaporation part of thermosyphon experimentally and numerically complete the experimental part and reached to numerical part and first must be validation with another research so I read more research like ALammar, lenhard, Zhang, ......etc.
start with Alammar research he used Ansys 15, I'm used Ansys 19 R2 I do it the mesh like him( 24522 for fluid domain and 9620 for solid domain total 34142) also, increased it to 75000 but the same problems which is the residual continuity increases and reached to 1.24, 2.45, and sometimes reached to 10 but the other parameters decreased to 10^-5 I have repeated it about 100 times Alammar used UDF but mine not because When I used UDF in Ansys 19 R2 appear the phrase in CONSOLE "the Pragma is obsolete" but I found it in cell zone definition used it but not improved the continuity residual and used Ansys 16 appear error although it correct Why I don't why
even I do it the lenhard research also I didn't the same results. I need the answer to the question
1-In Design Modular when sketch the thermosyphon used the following steps
a-draw two rectangular in one sketch xy (represent the wall) and correct the dimensions
b-draw in sketch 2, three rectangles, represent water medium, remaining part of evaporation section and the final condenser section in fluent the interface between the three section defined as interior because convert to fluent as wall. then mesh then define the boundary conditions in fluent define one mass transfer or two the continuity residual is not good and when used two there is condensation part appear on the wall but the temperature contour is not correct also, if used one mass transfer boiling of water delay not occur at he told at 0.1
then changed the sketch by drawing
a-two sketch xy two rectangles define surface for the first one and then define surface for the second then subtract with preserve the interior rectangle then used plane with slice to define the water level and level of division evaporation from condenser
in above two different sketches all surfaces form as one part
the same problems appear what should I do?
the level of water must be defined in design modular or in fluent.
Please, can anyone help me because I have e-mail all of them but they didn't answer.
and I'm remain at this validation about 7 months

[vinerm]

I am afraid, but there is an assumption in the post that almost everyone is aware of what you are talking about. It would be better to assume that people here know FD and CFD, but may not know anything about the literature or the work you are talking about. There is a large section of your query that is related to DM and not to Fluent. So, I'd suggest using the following forum

https://www.cfd-online.com/Forums/ansys-meshing/

As far as physical parameter, such as, water level is concerned, that needs to be defined in Fluent. The UDF you attached is not required since you can use inbuilt Evaporation-Condensation model. The UDF is incomplete as well, so, you should ignore that.

[luna]

Thank you very much and I'm very sorry because I'm very tired with this validation
his work is thermosyphon outer diameter 22mm inner diameter 20.2 with wall thickness 0.9mm consist of two section evaporation part with heat flux 7346 w/m2 and condensation part with convection heat transfer coefficient 1120 w/m2 surr temp 295 k filled with 65% water
I need only how we draw in steps this case in design modular of ansys fluent and mesh it reaching to define the boundary conditions
then in fluent used how much mass transfer one or two
if the continuity residual is increase how can reduced it if I changed the types of mesh with no. but not effect
Thank again for helping

[vinerm]

Are you interested in all the steps from CAD modeling in Design Modeler to Post-Processing? In that case, I'd suggest you to go through some basic tutorial wherein all these tools have been used.

[luna]

I know the procedure please I need only if I have thermosyphon filled with 65% water which the correct method to sketch it i.e. define the level of water in geometry or define it in fluent which is correct one because the residual of continuity increases with time how can reduced it this is the most problems in thermosyphon

[vinerm]

Fluent does not receive any information regarding physics from mesh nor can it read CAD. Therefore, any input regarding the physics has to be done within Fluent, such as, specification of water level. You cannot bring it from CAD nor does CAD have option to do this.

[luna]

Many thanks