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Flow rate calculation - 2D model - FSI
Posted Sep 5, 2012, 9:45 p.m. EDT MEMS & Nanotechnology, Fluid & Heat, MEMS & Piezoelectric Devices 1 Reply
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I have a 2D fluid flow model with a flow through a channel with rectangular cross-section. There is one inlet with non-zero inlet pressure and outlet with zero pressure.
After solving, in order to compute the volume flow rate , I started by going to Definitions > Model Couplings > Integration. I created a integration for the outlet boundary (which corresponds to the height of the channel in 2D view) and named it intop1
Then I went to Study > Update Solution (I had already computed the solution), then I went to Results > 1D Plot Group, then 1D Plot Group > Global.
In the Global plot I added the expression, intop1(fsi.U)*W which gives me values in m^3/s....where W is a constant and is the width of the channel.
Can someone confirm that this is the correct way to calculate volume flow rate?
Thank you.
After solving, in order to compute the volume flow rate , I started by going to Definitions > Model Couplings > Integration. I created a integration for the outlet boundary (which corresponds to the height of the channel in 2D view) and named it intop1
Then I went to Study > Update Solution (I had already computed the solution), then I went to Results > 1D Plot Group, then 1D Plot Group > Global.
In the Global plot I added the expression, intop1(fsi.U)*W which gives me values in m^3/s....where W is a constant and is the width of the channel.
Can someone confirm that this is the correct way to calculate volume flow rate?
Thank you.
1 Reply Last Post Sep 5, 2012, 10:06 p.m. EDT
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Posted:
1 decade ago
Hi
I would say probably yes, as velocity times area is the flow.
But you should perhaps ask yourself which velocity component to chose?
Normally I would use the normal flow velocity (normal to my outlet surface). If this is a vertical boundary and yor flow is horizontal, then u[m/s]*height_y[m]*Width_z[m] is te flow in [m^3/s], where height_y is integral of the boundary length.
And as fsi.u is the x direction flow density field per boundary length element it's normal to integrate it to get a total global value
Units corresponds too, so just get clear the direction or scalar product of the velocity vector and the boundary normal and I would say: you are there
--
Good luck
Ivar
I would say probably yes, as velocity times area is the flow.
But you should perhaps ask yourself which velocity component to chose?
Normally I would use the normal flow velocity (normal to my outlet surface). If this is a vertical boundary and yor flow is horizontal, then u[m/s]*height_y[m]*Width_z[m] is te flow in [m^3/s], where height_y is integral of the boundary length.
And as fsi.u is the x direction flow density field per boundary length element it's normal to integrate it to get a total global value
Units corresponds too, so just get clear the direction or scalar product of the velocity vector and the boundary normal and I would say: you are there
--
Good luck
Ivar