Simulation of Water Turbine with CFX

hydroturbines · July 23, 2014, 16:58

Hello everyone,

I am working on simulation of a water turbine with CFX.
This is my first work in CFD.
Type of turbine: Francis (radial runner).

I have all the measured data in real turbine (net head, flow and output power).

My doubt is:
What are the best boundary conditions for inlet and outlet ?

Example:
Inlet Conditions: flow
Outlet Conditions: pressure

or
Inlet Conditions: pressure
Outlet Conditions: pressure

I do not know with is the boundary conditions that ensures better results in simulation for efficiency and cavitation.

Please, help me, every reply would be appreciated.

Thank you very much.

maximilianomavica · November 12, 2024, 09:42

you should use velocity for inlet and pressure for outlet,.

zacko · November 18, 2024, 02:18

There is a good guideline for Turbomachinery on that forum regarding Setups. To understand the various BC in CFX, have a look into the documentation.

To evaluate cavitation, an pressure outlet BC can be used, to vary the downstream pressure.

July 23, 2014, 16:58	Simulation of Water Turbine with CFX	#1
hydroturbines New Member Julio Duarte Join Date: Feb 2014 Posts: 2 Rep Power: 0	Hello everyone, I am working on simulation of a water turbine with CFX. This is my first work in CFD. Type of turbine: Francis (radial runner). I have all the measured data in real turbine (net head, flow and output power). My doubt is: What are the best boundary conditions for inlet and outlet ? Example: Inlet Conditions: flow Outlet Conditions: pressure or Inlet Conditions: pressure Outlet Conditions: pressure I do not know with is the boundary conditions that ensures better results in simulation for efficiency and cavitation. Please, help me, every reply would be appreciated. Thank you very much.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Water Hammer Simulation in CFX	DomBern	CFX	14	October 27, 2014 10:51
ANSYS CFX simulation: Post CFX error	MInXD	CFX	3	May 19, 2013 20:24
Boundary condition setting regarding turbine simulation using CFX	Lacerlacer	CFX	11	March 12, 2012 10:32
Sliding mesh vs MRF in axial turbine simulation	Vito	FLUENT	3	December 21, 2011 05:57
uptodate water distribution network	fredius,magige,tanzanian,(e.a)	Main CFD Forum	0	January 27, 2002 08:10

November 12, 2024, 09:42		#2
maximilianomavica New Member maximiliano Join Date: Jun 2020 Posts: 21 Rep Power: 6	you should use velocity for inlet and pressure for outlet,.

November 18, 2024, 02:18		#3
zacko Senior Member Daniel Join Date: Feb 2017 Location: Germany Posts: 172 Rep Power: 9	There is a good guideline for Turbomachinery on that forum regarding Setups. To understand the various BC in CFX, have a look into the documentation. To evaluate cavitation, an pressure outlet BC can be used, to vary the downstream pressure.