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-   -   NASA ROTOR 67 modelling (http://www.cfd-online.com/Forums/fluent/99176-nasa-rotor-67-modelling.html)

mm.abdollahzadeh March 27, 2012 19:26

NASA ROTOR 67 modelling
 
dear all

I am trying to model the same rotor with fluent. my domain is extended enough ( i think). i have tested almost everything but i can not obtain the correct pressure ratio for the design mass flow rate. i am using standard k-w turbulance model with 1% of turbulent intensity and 0.0001 turbulant length scale. I have tested both pressre based solver and density based solver. i have tested also diffrent combinations for inlet and outlet boundary condition. for inlet mass flow inlet or pressure inlet and at outlet pressre outlet with/without targeting the massflow rate and radial equilburim activated.
i will be thankful to recive your recomandations.

(I can post also my case if you want to check)

Regards
Mahdi

mm.abdollahzadeh March 27, 2012 19:30

Quote:

Originally Posted by mm.abdollahzadeh (Post 351829)
dear all

I am trying to model the same rotor with fluent. my domain is extended enough ( i think). i have tested almost everything but i can not obtain the correct pressure ratio for the design mass flow rate. i am using standard k-w turbulance model with 1% of turbulent intensity and 0.0001 turbulant length scale. I have tested both pressre based solver and density based solver. i have tested also diffrent combinations for inlet and outlet boundary condition. for inlet mass flow inlet or pressure inlet and at outlet pressre outlet with/without targeting the massflow rate and radial equilburim activated.
i will be thankful to recive your recomandations.

(I can post also my case if you want to check)

Regards
Mahdi


acctually i am working with the grid that is on stansford university website. but at the moment i have some douts about the soliution procdure (as its my first case on rotors) .
i have seen that some guys are usingnot a extended geomtry in a way that inlet and outlet are placed in a position that experimental values of pressure and temperure and etc are avilable. but in my case geomtry is extended ( suppuse that it is enough). then i have just the pressure ratio and mass flow rate and temperate and pressure at inlet and some how the tempretaure at outlet.
Tin=288.2
Pin=101325
Tout=345.84
P.R=1.64
Massflow=33.25
number of blade=22

at the moment the temperature is not convergaing with density based solver ( and i have the warning related to "Temperature limited" )
but with pressure based solver everything is converging

the problem is that for both cases the pressure ratio is small maximum 1.5
and with mass flow is correct ( as i am using target mass flow rate)

i dont know exactly but i thinck there should be sth beyond grid (in fact my spanwise Mach number distrubition is not even similar :( to the correct results

mm.abdollahzadeh March 28, 2012 04:50

with pressure based solver i was able to obtain the correct pressure ratio and massflow rate. but still the distribution of Mach number is strange spesially near the out let.

rvl565 May 2, 2014 14:07

Hi,

Were you able to get this to work?
I havent been successful so far, i could use some help

thank!


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