DELTAE now has a library of fluid and solid types that are useful in thermoacoustic devices available. The (t)hermophysical menu selection (see Chapter V for further details) allows the user to have keyboard access to the properties of these elements for a given state (which defaults to the current temperature, pressure, acoustic frequency, and fluid or solid). This feature has proven so convenient that we often start DELTAE simply to look up the transport properties of gases. (For this purpose, it is often useful to have a dummy file present (e.g,. nil.in) that contains only a TITLE line. If you respond to the input file prompt with this filename, DELTAE will quickly go to the menu line and allow you to access the options.)
A companion to the (t)hermophysical menu selection is THERMophysical segment type, which takes no input parameters except for the fluid and solid type (again, see Chapter V for a summary). This segment can be inserted anywhere in a model where the user wants to know the fluid and solid properties at the local temperature and pressure, whatever they may be at the time. Both the .out and .dat files contain outputs for these properties where the segment is inserted. By using the plotting loops, tables of properties can be generated over ranges of temperature, pressure, or frequency by varying these values in a BEGIN segment, ending the model with a THERMophysical segment, and plotting as many of the outputs as are required.