An assigned entropy and pressure problem requires an assigned entropy for the total reactant mixture, a set of assigned pressures, and an estimated final temperature for the first pressure.   The entropy value is held constant for isentropic conditions.

The program will try to converge with only the possible gaseous products and then check on possible condensed products. Sometimes the temperature gets driven to a very low value in an attempt to reach convergence.   This is usually remedied by inserting one or two possible condensed products with the Insert dataset.   This helps the program converge on both the gaseous and condensed products.

Note that the Problem and Reactant datasets must be completed before using the Insert dataset.

There are no examples for this type of problem.   However assigned entropy and pressure equilibrium calculations are used for the isentropic exit points in the rocket problems.

PRESSURE UNIT
The user has four choices for pressure units: bar (default); atm; psia; and mmHg.   The selected unit applies to all values listed.

VALUES
Up to 16 pressure values may be entered in the table.   Default estimated temperature is 3800 Kelvin.   User has the option of changing it.   The assigned entropy value is divided by universal gas constant R resulting in s/R units of (g-mol)K/(g of mixture).

Use the ENTER, RETURN, or TAB key or click on the next empty cell after each table entry.

HELP
The Help button displays the help menu for the Assigned Entropy and Pressure (sp) Problem.

SAVE
The Save button saves the data and returns to the Problem dataset.

RESET
The Reset button resets the data to the default settings.