E E S Engineering Equation Solver for Microsoft Windows Operating Systems Commercial and Professional Versions

E E S

Engineering Equation Solver

for Microsoft Windows

Operating Systems

Commercial and Professional Versions

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 also solve differential equations, equations with complex variables, do optimization, provide linear and non-linear regression and generate publication-quality plots. Versions of EES have been developed for Apple Macintosh computers and for the Windows operating systems. This manual describes the version of EES developed for 32-bit Microsoft Windows operating systems, i.e., Windows 95/98/2000/XP.
There are two major differences between EES and existing numerical equation-solving programs. First, EES automatically identifies and groups equations that must be solved simultaneously. This feature simplifies the process for the user and ensures that the solver will always operate at optimum efficiency. Second, EES provides many built-in mathematical and thermophysical property functions useful for engineering calculations. 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 for most organic refrigerants (including some of the new blends), ammonia, methane, carbon dioxide and many other fluids. Air tables are built-in, as are psychrometric functions and JANAF table data for many common gases. Transport properties are also provided for most of these substances.
The library of mathematical and thermophysical property functions in EES is extensive, but it is not possible to anticipate every user's need. EES allows the user to enter his or her own functional relationships in three ways. First, a facility for entering and interpolating tabular data is provided so that tabular data can be directly used in the solution of the equation set. Second, the EES language supports user-written functions and procedure similar to those in Pascal and FORTRAN. EES also provides support for user-written modules, which are self-contained EES programs that can be accessed by other EES programs. The functions, procedures, and modules can be saved as library files which are automatically read in when EES is started. Third, external functions and procedures, written in a high-level language such as Pascal, C or FORTRAN, can be dynamically-linked into EES using the dynamic link library capability incorporated into the Windows operating system. These three methods of adding functional relationships provide very powerful means of extending the capabilities of EES.

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