## Fluids

#### how to define certain level of water in closed cube – VOF model

• AGAAMAZ
Subscriber
Hi everyonenI have a question pleasenIf i have a solid cube and i want to use VOF modelnI want to define a certain level of water and the rest is airnHow can i do itn
• Lugia_06
Subscriber
nYou can patch water vol frac = 1n
Ansys Employee
Thank you nYou can find more info at nPleas also search this forum. You can find many posts on VOF. nRegards,nKeyurnGuidelines for Posting on Ansys Learning ForumnHow to access ANSYS help linksnn
• AGAAMAZ
Subscriber
nthank you for your replynbut how can i determine a certain volume of the cube to patch it nthe cube is 1 m^3 and it has water of 0.07 hight and the rest is airn
• DrAmine
Ansys Employee
You define a cell register with field variable the coordinate in the gravity direction, You say mark all cells lower than 0.07 for example. With that register, you can patch the initial liquid volume.nn
• AGAAMAZ
Subscriber
nthank you for your reply sirni saw away on youtube : adapt - Region - and mark for example the volume with coordinates x=1,y=0.02,z=1nand in solution initialization we make patch for water volume fraction to this regionnis this the way you tell ? n
• AGAAMAZ
Subscriber
ni have another important question pleasenin general tab nas for Time : what is the difference bt. steady and transientnand if i choose steady , the results indicates what ? at a certain time or what ?nAnd is the result of steady & transient is the same or even close ?nif there is any source that explains that point in details , sir ?n
• DrAmine
Ansys Employee
Hello, the way in Youtoube is old but still working. We recommend doing that via Cell Registers which are stored in case files.n
• DrAmine
Ansys Employee
Regarding your second question about difference between steady and unsteady: Are you just starting from scratch learning Fluent without doing some classes or even doing some tutorials?.Steady: stationary state-Results do not depend on intial statenUnsteady: Transient the result you see are at certain time level.nBoth results will be the same if the final state is pseudo/quasi steady-state.
• AGAAMAZ
Subscriber
nthank you sir nyes i just started with ansys self learningni will tryn