rotating propeller - please help - it's urgent
 

hy please it's urgent. if you're having an ideea how can i resolve this case please write to me cause i'm in big problem

i'm having a propeller and it's having a speed of 3000 rot/min. the diameter it's 1.372 m and i've modelated half of it. i've done a domain about 30 m after it and 6 before and in its side 20 m. the problem is that i'm not having wright answers concerning speed and pressure and i'm receiving messages like "reversed flow in ... faces and turbulent viscosity limited to viscosity ratio of 1.000000e+05". here it's what i've done

i've used moving reference frame with k epsilon turbulence model

for the fluid, moving reference frame with 3000 rot/min round x=1 direction

for the entrance pressure-inlet gauge pression 0 direction vector x=1, turbulent intensity 1% and hidraulic diameter 0.09604

for the wall stationary wall

for the exit pressure outlet with all the options 0 and for k and epsilon also zero.

for the other exit (on the half cilinder- the domain) i've used pressure outlet

and simmetry for the simmetry plane

for under relaxation factord i've used the values recommended in this case in user guide

please tell me where i've done wrong cause i have to finish this till sunday and i don'k knew what to do. please cip dany

Re: rotating propeller - please help - it's urgent
 

Hi!

I think you should use periodic bc instead os symmetry...

Good luck

MATEUS

Re: rotating propeller - please help - it's urgent
 

I'm modelling marine propeller and having the same problem, now I'm trying different meshes with diferent boundary layer sizes, maybe it will work.

Mayby you have some e-notes??? I could send you mine.

Re: rotating propeller - please help - it's urgent
 

you're right there is an antisymmetry there i've done this model yesterday morning and with the others boundary layers that i've mentioned i steel have wrong values in air.

Re: rotating propeller - please help - it's urgent
 

if you're saying to me what are those notes, certenly.

Re: rotating propeller - please help - it's urgent
 

i've done the propeller and tomorow i'll see if it's good. send me what you have to modalate there and i'll see how can i help you

Re: rotating propeller - please help - it's urgent
 

Hey, maybe you could send me your mesh file and case file???

it104370@kufel.immt.pwr.wroc.pl

TIA Lukasz