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Time Dependent of intake manifold
Posted Mar 26, 2017, 9:30 p.m. EDT Fluid & Heat, Computational Fluid Dynamics (CFD), Studies & Solvers Version 5.1, Version 5.2, Version 5.2a 1 Reply
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Hello,
I am having an issue trying to simulate an intake manifold of 4 cylinders. I want to do it as transient flow. But in real life the each cylinder is not open at the same time. How do i tell COMSOL to open an outlet and close another one at a certain time,
Regards,
Thank you
I am having an issue trying to simulate an intake manifold of 4 cylinders. I want to do it as transient flow. But in real life the each cylinder is not open at the same time. How do i tell COMSOL to open an outlet and close another one at a certain time,
Regards,
Thank you
1 Reply Last Post Apr 11, 2017, 8:09 a.m. EDT
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Posted:
7 years ago
Hello Manuel,
Why don't you simply define your inlets as a function of time? You can choose the proper function that you want by right clicking on Definitions (under Component 1).
For example Step function works well for the case you want to open/close a valve once. By using waveform function you can define a sinusoidal function to open and close your valve repetitively, take a look at other functions as well.
After defining the function you can apply it directly into your boundary condition. For example if currently you have an inlet boundary condition of constant value of ''0.1'', then you should change it to ''0.1*step1(t[1/s])''
Here, step1 is the function you already defined and [1/s] removes unit of time to make it dimensionless.
If you want to apply a delay for each valve, either define 4 functions or add the delay directly in each of the boundary conditions like this: ''0.1*step1(t[1/s]+delay)''
Best regards,
Reza
Why don't you simply define your inlets as a function of time? You can choose the proper function that you want by right clicking on Definitions (under Component 1).
For example Step function works well for the case you want to open/close a valve once. By using waveform function you can define a sinusoidal function to open and close your valve repetitively, take a look at other functions as well.
After defining the function you can apply it directly into your boundary condition. For example if currently you have an inlet boundary condition of constant value of ''0.1'', then you should change it to ''0.1*step1(t[1/s])''
Here, step1 is the function you already defined and [1/s] removes unit of time to make it dimensionless.
If you want to apply a delay for each valve, either define 4 functions or add the delay directly in each of the boundary conditions like this: ''0.1*step1(t[1/s]+delay)''
Best regards,
Reza