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Old   May 11, 2018, 00:03
Default mass flow
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liyong
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In my case, I set a inflow boundary for injecting hydrogen. The boundary type I choose is mass flow, and the profile as attachment(mass_flow.png) shows.
In the result of mass_avg_flow is showed in attachment(mass_flow_rate.png), and it looks normal, but the total mass of hydrogen in species_mass.out is wrong. I caculated the mass of hydrogen if it is injected by the profile, theoretically,it should be 4.6mg. However, the result from CONVERGE is 4.1mg(mass_H2.png), and the error is 10.9%. It's abnormal, but I don't know why?
The follow is caculation procese:
engine speed=1500rpm, so crank angle speed is 1500*360/60=9000CA/s
massflow is 2235.98mg/s, equally 2235.98/9000=0.2484mg/CA
so total mass:0.2484*(17.5+19.5)/2=4.6mg
Attached Images
File Type: png mass_flow.PNG (18.0 KB, 22 views)
File Type: jpg mass_flow_rate.jpg (79.4 KB, 17 views)
File Type: jpg mass_H2.jpg (66.5 KB, 13 views)
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