negative pressure significance

[Ranjan kumar]

Hi,
I have run a simulation of pulsate nature for 3 cycle but the result comes is negative at inlet pressure and approximate zero at outlet pressure
flow should be in high pressure to low pressure(by voltage analogy)
but mine is coming negative; is it mean vacuum pressure(not on absolute scale)?
that is sucking tendency at inlet or i have done something wrong in simulation?
I am considering my model as rigid and outlet resistance as zero.

https://drive.google.com/drive/folders/ ... drive_link

[David Parker]

Hello,

Your inlet geometry looks odd, like it is does not have an opening. And make sure you inlet velocities are negative.

Cheers,
Dave

[Ranjan kumar]

sorry for bad quality image, i am sending with better view.
yes,my inlet velocity is negative and i have also shared models and inlet data via google drive previously
again previous query remain same
I have run a simulation of pulsate nature for 3 cycle but the result comes is negative at inlet pressure and approximate zero at outlet pressure
flow should be in high pressure to low pressure(by voltage analogy)
but mine is coming negative; is it mean vacuum pressure(not on absolute scale)?
that is sucking tendency at inlet or i have done something wrong in simulation?
I am considering my model as rigid and outlet resistance as zero

And thanks for responding every time even if the problem is simple

[David Parker]

Hello,

It's not clear what might be wrong. Check that the inflow waveform is correctly imposed on the inlet, look at velocity vectors maybe, make sure the units are consistent with your outlet BCs.

Cheers,
Dave