Inlet Flow Velocity or pressure gradient - modeling of a Wind Turbine Blade case

LittleBart · January 6, 2011, 08:36

Dear friends,

I'm working on the case when I have to simulating airflow over a wind turbine blade. The problem is to determine total lift and drag force occurred over the blade in rotation but instead of making rotating blade and solve transcendent case, I've decided to apply velocity gradient to the Inlet BC. wR - gradient will simulate the blade's rotation.

The question is how to apply such a parameter of the BC ?

Was trying to do this with CFX 12 and Fluent but didn't succeed

Nixmich · January 6, 2011, 09:53

Hi, dunno abount Fluent but in CFX pre you can "add an Expression" like vel=2*x/1[s] and then just type "vel" as the inflow speed. Is that what you mean?

LittleBart · January 7, 2011, 07:42

Thanx

is there any place in help or other documentation where I can read about such an expressions ?

and one more - in your example as I understood "x" - is a coordinate? Do I have to create special coordinate frame or coordinate system to specify this coordinate frame?

thnx once again

RobertB · January 7, 2011, 08:06

Can't you pose the problem in a rotating reference frame? It would make the setup easier.

Nixmich · January 10, 2011, 02:23

you don't have to set up an extra coordinate frame, x refers to the one in which you set up your geometry.

anyway, it's all in the cfx tutorials.

LittleBart · January 10, 2011, 15:07

Thanx, I will lurk more ...

I'm just beginner in such analysis so I just don't now what book to begin with.. But I will try anyway ... thnx

January 6, 2011, 08:36	Inlet Flow Velocity or pressure gradient - modeling of a Wind Turbine Blade case	#1
LittleBart New Member LittleBart Join Date: Jan 2011 Posts: 20 Rep Power: 15	Dear friends, I'm working on the case when I have to simulating airflow over a wind turbine blade. The problem is to determine total lift and drag force occurred over the blade in rotation but instead of making rotating blade and solve transcendent case, I've decided to apply velocity gradient to the Inlet BC. wR - gradient will simulate the blade's rotation. The question is how to apply such a parameter of the BC ? Was trying to do this with CFX 12 and Fluent but didn't succeed

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January 6, 2011, 09:53		#2
Nixmich New Member Lukas Join Date: Nov 2010 Posts: 11 Rep Power: 15	Hi, dunno abount Fluent but in CFX pre you can "add an Expression" like vel=2*x/1[s] and then just type "vel" as the inflow speed. Is that what you mean?

January 7, 2011, 07:42		#3
LittleBart New Member LittleBart Join Date: Jan 2011 Posts: 20 Rep Power: 15	Thanx is there any place in help or other documentation where I can read about such an expressions ? and one more - in your example as I understood "x" - is a coordinate? Do I have to create special coordinate frame or coordinate system to specify this coordinate frame? thnx once again

January 7, 2011, 08:06		#4
RobertB Senior Member Robert Join Date: Jun 2010 Posts: 117 Rep Power: 16	Can't you pose the problem in a rotating reference frame? It would make the setup easier.

January 10, 2011, 02:23		#5
Nixmich New Member Lukas Join Date: Nov 2010 Posts: 11 Rep Power: 15	you don't have to set up an extra coordinate frame, x refers to the one in which you set up your geometry. anyway, it's all in the cfx tutorials.

January 10, 2011, 15:07		#6
LittleBart New Member LittleBart Join Date: Jan 2011 Posts: 20 Rep Power: 15	Thanx, I will lurk more ... I'm just beginner in such analysis so I just don't now what book to begin with.. But I will try anyway ... thnx