screetch82
Mechanical
- Nov 12, 2003
- 16
hello I am an intern and have to to a research for a printing press manufacturer. I have to compute the air flow
in a 3d duct. the duct ends with an small outlet which leads to a rotating cylinder. The cylinder has small chambers on the circumference. The outlet
of the duct covers 2 of the chambers. The air flow is created by sucking out the air of the small chambers through the duct.
All I know is the negative pressure which is produced by the vacuum pump. I know flotran computes an airflow using a press difference
But all I have is the pressure on one end and the volume of air on the other end? Can someone give me some hints how to do this calculation?
I have already modelled the duct and have done a few sample calc. But in order to even start the solution I set the pressure on the outlet (the vac-pump) to 0
and the pressure at the inlet (the opening where the suction ring is) to 80 kpa. So the pressure difference gave me and airflow.
The problem is that in reality the pressure drop is the other way around and I know just the outlet pressure. The inlet pressure decreases as more air is
sucked out of the chamber. Right? How do I do this? how do I work with neg pressures in flotran?
can someone give me parts of a simple input file relating to my problem? I'd be happy if some emails me..for fast communication.to screetch@gmx.net
in a 3d duct. the duct ends with an small outlet which leads to a rotating cylinder. The cylinder has small chambers on the circumference. The outlet
of the duct covers 2 of the chambers. The air flow is created by sucking out the air of the small chambers through the duct.
All I know is the negative pressure which is produced by the vacuum pump. I know flotran computes an airflow using a press difference
But all I have is the pressure on one end and the volume of air on the other end? Can someone give me some hints how to do this calculation?
I have already modelled the duct and have done a few sample calc. But in order to even start the solution I set the pressure on the outlet (the vac-pump) to 0
and the pressure at the inlet (the opening where the suction ring is) to 80 kpa. So the pressure difference gave me and airflow.
The problem is that in reality the pressure drop is the other way around and I know just the outlet pressure. The inlet pressure decreases as more air is
sucked out of the chamber. Right? How do I do this? how do I work with neg pressures in flotran?
can someone give me parts of a simple input file relating to my problem? I'd be happy if some emails me..for fast communication.to screetch@gmx.net