by nrgeng » 13 March 2013, 14:02
Last month I completed a simulation to determine the amount of space heating created by dissipating the thermal energy from the condenser of a vapor compression machine. For that simulation, I created a mixture of four pure components: nitrogen, oxygen, argon, and carbon dioxide, having a mixture molecular weight of 28.9 g/mol. In other words, I made up my own air. While researching this latest question, I noticed in PCDman that air is available in the chemical database. I thought that I looked for air in the past but apparently I missed it. The air that is in the chemical database is a mixture of pure components and may have been set up using the method that you described to add Dowtherm A, which is also a mixture of pure components.
As an alternative method to the one that you suggested, since biphenyl is already in the chemical database, if I added the other component of Dowtherm A, which is diphenyl ether, and chose an appropriate ratio of the two, would that have the same effect as making a new entry simulating the mixture as a pure component with PCDman? If that is true, how do I enter diphenyl ether as you alluded to in your last response in the second sentence, “This is possible, but the automated functionality to get the properties from the NIST web site will not work.” Do you mind explaining how the automated functionality to get the properties from the NIST web site works, in order to avoid my adding the properties manually? Diphenyl ether (101-84-8) is in the NIST database.