[ArathoN]

hi foamers,

I'm trying to simulate a channel with rectangular section so that i can take the outlet values of velocity and turbulent energy and feed it directly as input of my main simulation (the backward facing step case). My initial data are:
- U(developed flow) max =8.7
- I around 7 % (i calculated it from the experimental data of makiola for the backward facing step)
- Re= 15000 (then i'll do the same for the 64000 Re)
- y plus is less than 1 all over the domain for both the walls
- using the simplefoam solver with KEpsilon model


First i tried using a normal mesh but here i faced a little problem what value of the velocity should i consider, knowing the maximum velocity at the outlet. And i didn't find any publication where they studied the relation of the fully developed velocity flow and the inlet flow. I founded only a ppt of an Indian professor where he states that U(developed flow) = 1.5 U(inlet) but it isn't correct. Do any of you know any useful reports about this?

Second i used the cyclic condition, and because the mesh was done with gambit i've created the patch thanks to the createPatchDict library. The problem is that the epsilon variable doesn't converge. And i don't know what to do, please help me.

P.S. I found that i can use the data from a different case into another one by using one of these function:
- directmapped
- cyclic
- TimeVaryingMappedFixedValue
but i didn't understand exactly what they do (and i read a lot of threads here), from what i grasped the "cyclic" will link to patch creating a infinite loop so in the case of the channel it's like simulating an infinite channel; the "TimeVaryingMappedFixedValue" will do an interpolation in space and in time (what does this mean? if i give the value of a variable in 2 different times will it do an interpolation of the same variable over the two times given?.
I found close to nothing for the directmapped function, also the tutorial case where it was used now use the "TimeVaryingMappedFixedValue" condition.
If someone can link me some good and useful threads or directly explain it to me, i would be really really grateful.

PPS: i attached my "\0" and "\system" directories so please look at it and tell me what i'm doing wrong.