Hello, I want to model a window vent in energyplus by using a crack in an airflow network. Is there a way to limit the mass flow rate through a crack to a constant (maximum) value from the moment that a certain pressure difference over the crack is reached? I can't figure out how to do this.
This problem is tackled in the Ventilation Controls Virtual Test Bed. A paper containing more info can be found on: https://lnkd.in/dCVkSzg free download before March 21, 2019.
The Airflow Network is unable to do what you want. The model calculates flow rate based on pressure difference across a crack only. I will add an enhancement item for future development.
Hello, thank you. I already altered the source code for the linear calculation option so that a deltaP maximum can be defined in an extra input field in the crack component. If deltaP > deltaPmax --> deltaP=deltaPmax.I don't get any errors for the moment, but I still have to do some tests.
Hello. After some testing the altered code didn't converge to a solution. I thought that this could be the result of the slope suddenly (instead of gradually) becoming zero at deltaPmax. I took a look at the self-regulating Vent model in contam (based on Axley, AIVC TN54 pp41-44) and I have tried to implement this (Q=Qref.(1.0-exp(-DP/DPref)) in the C++ code. The code compiles, but there is still no convergence. I have send you the altered source code files by mail. Could you have a look at them please. Thank you.
Asked: 2015-06-22 04:22:59 -0600
Seen: 428 times
Last updated: Jan 30 '19
