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PISO 50 with discarge coeff down???

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Old   January 24, 2008, 21:00
Default PISO 50 with discarge coeff down???
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Hi everybody,
when I simulate a Diesel ICE I get these results with a discarghe coeff Cd = 0.825: when I use underela = 0.7, scalar underela = 0.5 and drnp = 0.35 I get maximum PISO = 12 from the time of start of injection (SOI) til the end of combustion.
Instead, when I use Cd = 0.7 I get PISO > 50 many times at the start of combustion...and PISO < 12 after the start of the combustion...what is a possible reason in your opinion???
I've see the when the Sauter Mean Diameter drop under 10 micron (when Cd go down velocity rise up...) I get PISO > 50...but with the Lagrangian approach it should be better that the droplet is much low compared to the cell...where am I wrong?
And also...I've tried to run with time step at 1/10 of the original, also with underela = 0.5, underela of scalar = 0.3 and drnp = 0.1...I always get the same results!
Plase share your ideas!

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Old   February 1, 2008, 14:33
Default Re: PISO 50 with discarge coeff down???
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nobody has any idea about this problem???
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