BTW, how is your inflow? I hope not uniform....

I'm trying to resolve the Streamlines "deformation" provoked by the object, the idea is to simulate a turbulent flow in a gutter and see how much the Streamlines deform in the vertical direction, and how much the cavity grows, and if it is independent of the flow inlet velocity and how it varies from an object with a rectangular shape to a semicircular shape and triangular shape (Keep in mind I don't want to make a multiphase simulation). As u mention I think I might be making huge mistakes in my BC's and yes my inflow is uniform, sorry for my lack of knowledge in this area I'm pretty new at CFD in general and also for my grammar and spelling, and thank you for ur time!

also... thank you for pointing out that paper I will check it out! 😁

Who said you need multiphase?

Anyway, flow passing through a gutter may hardly ever be uniform. That's the first thing you want to fix.

Back then a lot of people told me that maybe i need multiphase simulation

well, you can easily do a 1D gradually varied flow analysis over your obstacle to determine whether you actually need to represent the free surface! It is not up to us to decide how you should conduct your research, but on you to provide evidence on the choices you make regarding your simulation.

for this purpose can i just extend my domain so there is a lot of more room for the flow to develop before the object?..also do u know what bcs could be ideal for the top wall i already tryied a lot of different options but my situation seems not to change a lot

That seems like a waste of resources to me, because there you have a fully developed boundary layer flow

I really appreciate your comments, I'm just trying to learn the most that i can in this field that is pretty new to me

It is better to run a precursor simulation on a straight channel with the correct Re, and then extract the data from there to the inlet of your simulation

One may argue that we know the mean velocity profile for wall-bounded flows but,

for fields such as kappa, and nut, you'll also have a sort of "boundary layer" that needs to be correclty imposed at the inlet

As a first step, at least, set the correct velocity profile at the inlet

Got it, i will try to correct my inlet velocity profile and see wheter my bcs are well defined, do I need to set kappa even if i'm doing isothermal simulation?, thank you very much for ur help.

kappa is the TKE or turbulence kinetic energy

Important (not really) to note. Particularly for english speakers: the $\kappa-\omega$ model is not pronounced "kay"-omega, but "kappa"-omega. Is the greek letter that's being used.

Ohhh I see, sorry for my ignorance I'm no native english speaker ahaha, i will keep it in mind, thank you for all the help you provided to me.😅 😄

i, as a non-english speaker, always thought it was kappa-omega but never saw a single 'kappa' anywhere. so i just got used to 'kay'. now i'm re-confused again

I think he is trying to trick us

don't be fooled guys

in any book of turbulence you'll see TKE twritten as $\kappa$It's all part of a master plan

Whoops

All your understanding of turbulence down the drain, huh?

Never heard about the k-e RANS model ?

lol yeah, none of the equations is valid anymore 😄

Happened to me when I learned $\tau$ is not pronounced "TAU", but "TAF"