一、EES（engineering equation solver）
Engineering Equation Solver
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.
EES是一款（工程用）方程（公式）求解器的英文简称。它主要用于求解一系列的代数方程。例如：数百个非线性的方程构成的代数方程组
它和现在一般的方程求解器的一个主要不同在于，它内置了大量数学和热力学方面的函数。例如精确实现了水蒸气的焓熵表（H，V，S；P；T），使得由任何两个通过函数调用时传入的参数就能获得水蒸气的第三个参数值。（P，T>>H）对于象氨，氮，甲烷，丙烷，所有普通氟氯化碳制冷剂，R-134A（一种环保型制冷剂不含氯）这一类的流体EES也提供了相似的便利。空气性质表也通过内置的湿度函数得以实现而且还同时实现了许多（如果包括不同物相有3千多组）常见气体的JANAF热力表。它还包括一些流质传递相关的函数。其中热力学相关的函数同时支持国际标准单位和英制单位。EES还支持用户自定义数据库补充属性数据。
EES能够自动判别参数的独立性。所选变量均被包含在一张可扩展的电子数据表格中。用户只需要把相互独立的变量的值填入表中对应单元中，它就能自动计算出相关变量的值并能自动生成表格中任意两个被选变量的关系图象。并且多张图纸可以覆盖生成，结果图可以根据需要通过与程序兼容的打印机输出到一般出版物的附录中。
初学者通过EES只需要使用一些简单直观的命令就能解决许多复杂的数学问题。EES内嵌的大量热力学和流体力学方面的数据使得它在解决工程热力学，流体力学，传热学的许多问题上都显得相当的快捷和便利。用户还可以通过自定义函数（用PASCAL，C，EES写成）或者表单来加入自己的数据，而这些数据将会被EES自动插入它自己内置的数据库中。因为这些原因，EES被广泛用于解决各个工程领域中的问题。
EES 轻松省节能技术
技嘉研发的 主板 EES轻松省节能技术（Easy EnergySaver），
二、学校简称Guancheng English Experimental School——莞城英文实验学校的简称：EES
