[dandanTT]

Hi Foamers,

How can I define a FlowRate boundary condition for a inlet that varies with time? For example, flowrate = sin(t). Thank you all for helping.

[RenMon]

hello, I think you can try using the "flowRateInletVelocity" boundary condition and then specify "table" in the value section. Something like this:

inlet
{
type flowRateInletVelocity;
uniformValue table
(
(0 1)
(0.1 2)
(0.2 3)
(0.3 4)
);
}

in this way the flowrate will be linearly interpolated between the time values (0; 0.1; 0.2; 0.3). You just need to create a sine function and use it in the table section. I never tried this but it should work. Otherwise, you can use the boundary condition "uniformFixedValue". In this case, you should compute the velocity starting from your patch's area and flowrate and then use the same strategy with the table. For example, by assuming that your patch is a plane patch of normal (1 0 0):

inlet
{
type uniformFixedValue;
uniformValue table
(
(0 (1 0 0))
(0.1 (2 0 0))
(0.2 (3 0 0))
(0.3 (4 0 0))
);
}

[dandanTT]

Thank you for your kindly reply.

"uniformFixedValue" does not work in my case.

The "table" method might be working, but while looking, I realized other options like "sine" or "codedFunction1" from this page. However, I have no idea how to set it up.