CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Phoenics (http://www.cfd-online.com/Forums/phoenics/)
-   -   K-E model (http://www.cfd-online.com/Forums/phoenics/67099-k-e-model.html)

shineone August 3, 2009 23:08

K-E model
 
hello everyone

i am using K-E model for simulation in downtown area.
could you please tell me how to set wind profile in this software.

Thank you very much for your help

phoenics_cfd August 11, 2009 07:20

Wind profile
 
The wind object is described here:

http://www.cham.co.uk/phoenics/d_pol...m#Wind_Profile

and the wind_profile object here:

http://www.cham.co.uk/phoenics/d_pol...-type.htm#Wind

The wind object is very closely related to the wind_profile object. The latter specifies only the wind inflow boundaries, but later versions of PHOENICS are eqipped with the wind object, which is a single object that always fills the entire domain. Based on the wind direction it creates inflow boundaries at the domain edges using logarithmic or power law profiles on the upwind faces, and fixed pressure boundaries on the downwind faces. In addition, the upper, or sky boundary can also be made into a fixed pressure boundary.

migao August 12, 2009 04:01

nice!PHOENICS is becoming easiler to use!

shineone August 12, 2009 09:02

thanks
 
thank you very much
it is really helpful
i will try follow your instructions

shineone August 14, 2009 10:00

Thank you, Michael
the dialog you showed to me is exactly what i want to set for wind profile
but I am using phoenics 3.5, it doesn't show the settings as you showed. could you please tell me How can i set these parameter such as roughness height in Phoenics 3.5.

and also i have some problem with relaxation control.
could you please tell me how can i get convergence.
thank you very much.

phoenics_cfd August 14, 2009 11:40

Wind profile
 
There are three alternative methods of introducing a wind inlet boundary condition, as follows: (a) a PIL Do loop over the inlet height in the Q1 file with appropriate PATCH and COVAL statements (see library case T306 as an example ); (b) a single PATCH per inlet plus COVAL statements, with the inlet values supplied via FORTRAN coding in Group 13 Section 12 of GROUND; or (c) a single PATCH per inlet plus COVAL statements, but with INFORM commands to define the wind inlet values, as in the example below, which will need two INLET PATCHes (named BLINL and BLINLW) in the Q1 file plus COVAL statements:

************************************************** **********
Echo InForm settings for Group 13
inform13begin
REAL(VREF,REFHEIGHT,RHIN,ROUGHH,AKAP,ZRFDRH)
REAL(VTAU,VTAUX,VTAUZ)
REAL(VELX,VELZ,IN_ANG,PI)
** constants
AKAP=0.41;PI=3.1415926
** wind speed, reference height, roughness height
VREF=1.5;REFHEIGHT=10.0;ROUGHH=0.022
** wind incidence angle
IN_ANG=30.0*PI/180.

VELZ=VREF*COS(IN_ANG)
VELZ

VELX=VREF*SIN(IN_ANG)
VELX

ZRFDRH=REFHEIGHT/ROUGHH

VTAU=VREF*AKAP/LOG(ZRFDRH)
VTAU

VTAUX=VELX*AKAP/LOG(ZRFDRH)
VTAUX

VTAUZ=VELZ*AKAP/LOG(ZRFDRH)
VTAUZ


RHIN=1.189
CHAR(FORM1,FORMX,FORMZ,FORMK,FORME)

FORM1=VTAU/AKAP
FORMX=VTAUX/AKAP
FORMZ=VTAUZ/AKAP

FORMK=VTAU^2/0.3
FORME=VTAU^3/AKAP

(SOURCE OF P1 AT BLINL IS RHIN*(:FORMZ:*LOGE(YG/:ROUGHH WITH IMA$
T<100)
(SOURCE OF U1 AT BLINL IS RHIN*(:FORMZ:*LOGE(YG/:ROUGHH*:FORMX:*$
LOGE(YG/:ROUGHH: WITH IMAT<100)
(SOURCE OF W1 AT BLINL IS RHIN*(:FORMZ:*LOGE(YG/:ROUGHH*:FORMZ:*$
LOGE(YG/:ROUGHH: WITH IMAT<100)
(SOURCE OF KE AT BLINL IS RHIN*(:FORMZ:*LOGE(YG/:ROUGHH*:FORMK: $
WITH IMAT<100)
(SOURCE OF EP AT BLINL IS RHIN*(:FORMZ:*LOGE(YG/:ROUGHH*:FORME:/$
YG WITH IMAT<100)

(SOURCE OF P1 AT BLINW IS RHIN*(:FORMX:*LOGE(YG/:ROUGHH WITH IMA$
T<100)
(SOURCE OF U1 AT BLINW IS RHIN*(:FORMX:*LOGE(YG/:ROUGHH*:FORMX:*$
LOGE(YG/:ROUGHH WITH IMAT<100)
(SOURCE OF W1 AT BLINW IS RHIN*(:FORMX:*LOGE(YG/:ROUGHH*:FORMZ:*$
LOGE(YG/:ROUGHH WITH IMAT<100)
(SOURCE OF KE AT BLINW IS RHIN*(:FORMX:*LOGE(YG/:ROUGHH*:FORMK: $
WITH IMAT<100)
(SOURCE OF EP AT BLINW IS RHIN*(:FORMX:*LOGE(YG/:ROUGHH*:FORME:/$
YG WITH IMAT<100)

inform13end

shineone August 15, 2009 22:23

Thank you
 
Thanks a lot Michael

I am trying this programming.
and seems it can get better result.
thanks again.


All times are GMT -4. The time now is 03:14.