CAPLIM: a Visual Basic program to calculate the capillary limit of an axially-grooved heat pipe

The program CAPLIM predicts the capillary limit of an axially-grooved heat pipe as a function of working temperature and heat pipe geometry. Calculations for water, ethanol, and ammonia are built into the program, and a user-defined function is provided to allow for the addition of other working fluids. The thermal-fluid properties of the working fluids are approximated by polynomial curve fits as functions of temperature. The Visual Basic programming language incorporated into Microsoft EXCEL (Version 5.0a) is used to perform the calculations and plot the capillary limit as a function of temperature. A sample calculation is provided to ensure proper operation of the program. A listing of the program code is available which includes a variable dictionary and an explanation of the program flow. This program can be used as a design tool to quickly evaluate potential heat pipe/working fluid combinations.