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synthetik-technologies / blastfoam

A CFD solver for multi-component compressible flow with application to high-explosive detonation, explosive safety and air blast
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2D Poiseuille flow #61

Open lucafadigati opened 1 year ago

lucafadigati commented 1 year ago

Good morning,

blastFoam has been tested on simple case: 2D Poiseuille flow, where the pressure drop has been set between the inlet and the outlet of the 2D pipe. The maximum velocity expected at the channel centerline should be 1.24997 mm/s (such value has been computed analitically using 2D Poiseuille formula and then verified with rhoCentralFoam solver); actually blastFoam computed a velocity of 1.3773 mm/s. The simulation files are provided in attachment.

Thanks, Luca

2DPoiseuilleCase.zip

jheylmun commented 1 year ago

Hi Luca, Thank you for bringing this to my attention (and sorry for the long delay). I am still trying to figure out why the results differ, since every thing should be the same. I will let you know I do figure out what is causing the discrepancies though. Out of curiosity, have you tried a higher Mach number flow as well?

Thanks, Jeff

carlo-fiorina commented 1 year ago

Hi. Was this issue resolved?

lucafadigati commented 1 year ago

Hi, I am sorry but I have been busy and forgot to check github. I have run a simple simulation inside a channel, the flow is subsonic at the inlet and it becomes supersonic after the nozzle throat. I tried to use blastReactingFoam because in the futures I would run some simulations with chemical reactions. The issue that I have found is related to the viscosity. I am imposing a noSlip condition on the walls patch but the velocity does not go to zero, it remain constant across the nozzle section. Maybe I am using your solver in the wrong way. I have imposed a static pressure at the inlet and "pressureInletOutletVelocity" for U field. I know your solver was designed for explosion but I don't understand what mistake I made in the simulation settings.

Best regards, Luca