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Specify inflow
Posted 7 sept. 2013, 08:44 UTC−4 Microfluidics Version 4.3a 3 Replies
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I'm dueling with a problem and I'm a very recent user of COMSOL so probably this is an easy thing but not that simple for me. So, I'm trying to simulate the flow of a specific amount of fluid from a main inlet to a "chamber", with a small outlet. The way I was thinking of doing it was to define a function with a step form to control the flow rate of the laminar inflow in my inlet, doing something similar to what was proposed here www.comsol.com/community/forums/general/thread/24784/.
But, for some reason that I don't understand, no matter how much time of inflow that I define, the fluid stops right before the chamber entrance. Do you think that it as something to do with my boundaries definitons or the function that I'm using is not the best aproach or something like that?
Thanks in advance for anykind of help :)
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then inflow could be
Vin*(1-flc2hs(Tp-t,0.001))
The latter parameter defines the steepness of the pulse raise.
Now inflow = Vin, t < Tp and 0, t > Tp.
I wonder if this is what you asked ;)
BR
Lasse
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Well, frst of all I not sure what do you mean by function "flc2hs". Is that a predefined function of Comsol?
The way I was doing it was to first define a parameter "vol" with the amount of flow that I want (10e-9 m^3/s), for instance). Then I defined a step function, with values from 0 to 1, centered at 2s. After that, I created an analytic function whose expression is defined as: vol - vol*step1. I thought that this way, if I define my microfluidic inlet as a laminar flow with this function, it would control the amount of fluid that would enter the system.
I think that my approach is similar to the one you're proposing, but I really dont know waht do you mean by that function "flc2hs". Do you think that my approach is the best?
Thanks in advance,
Carlos H
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Well, frst of all I not sure what do you mean by function "flc2hs". Is that a predefined function of Comsol?
The way I was doing it was to first define a parameter "vol" with the amount of flow that I want (10e-9 m^3/s), for instance). Then I defined a step function, with values from 0 to 1, centered at 2s. After that, I created an analytic function whose expression is defined as: vol - vol*step1. I thought that this way, if I define my microfluidic inlet as a laminar flow with this function, it would control the amount of fluid that would enter the system.
I think that my approach is similar to the one you're proposing, but I really dont know waht do you mean by that function "flc2hs". Do you think that my approach is the best?
Thanks in advance,
Carlos H