EES (pronounced 'ease') is an acronym for Engineering Equation
Solver. The basic function provided by EES is the solution of a
set of algebraic equations. EES can efficiently solve hundreds of
coupled non-linear algebraic equations. EES can also be used to
solve initial value differential equations.
A major difference between EES and existing equation solving
programs is the many built-in mathematical and thermophysical
property functions which EES provides. For example, the steam
tables are implemented such that any thermodynamic property can
be obtained from a built-in function call in terms of any two
other properties. Similar capability is provided many other
fluids, e.g., ammonia, nitrogen, methane, propane, all common CFC
refrigerants, R-134a and others. Air tables are built-in, as are
psychrometric functions and JANAF table data for many common
gases. Transport property functions are also provided.
Thermophysical property functions operate in either SI and
English units. Additional property data may be added by the user.
EES provides the capability to do parametric studies. Selected
variables can be included in a spreadsheet-like table. The user
determines which variables are independent by entering their
values in the table cells. EES will solve the table to determine
the values of all dependent variables. A plotting option is
provided to display the relationship between any two variables in
the table. Multiple plots can be overlayed. Publication quality
plots can be output on Postscript - compatible printers.
EES offers the advantages of a simple set of intuitive
commands with which a novice can quickly learn to use for solving
numerical problems. The large data bank of thermodynamic and
transport properties built into EES are helpful in solving
problems in thermodynamics, fluid mechanics, and heat transfer.
Additional data can be added by the user as functions (written in
Pascal, C, or EES) or in a tabular form, which EES will
automatically interpolate. As a result, EES is can be used to
solve problems in any engineering application.
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information, ordering information, and downloadable
demonstrations for EES.
Department of Mechanical Engineering
University of Wisconsin-Madison