WP34S - f SLV used with user selectable variables

[gomefun2]

There are a lot of problems I solve that require an excess of 100 variables. I programmed an Excel spreadsheet (in VBA) to calculate pressure drop (Beggs Brill/Modified Hagedorn and Brown Method (With Griffith Correlation)) and I remember counting more than 100 variables and 17 sub-functions.

For a single equation, there are quite a few that I use that have ten or more variables that rely on other equations with just as many variables.

Of course, you could look at the Navier-Stokes Equation, and program a general solver (although I have never wanted to do this):

https://www.grc.nasa.gov/www/k-12/airplane/nseqs.html

I was thinking more of the Material Balance Equation:

http://www.fekete.com/SAN/WebHelp/Fekete...Theory.htm

The basic form has 33 pieces (maybe a couple pieces repeat).

I've heard there are more complex forms of this equation. Such as MBE for gas condensate reservoirs, that I get to learn about in my final year of engineering school (start next fall), and I am unsure the form they take in material balance. I assume they are more complex (so I estimated 40 variables), but I am unsure.

At any rate, I'll look at what you have here. The main reasons I don't like the hp 35s at the moment are 1) only 26 program labels (A to Z) 2) can't solve and integrate the same function at the same time in the same program

If only we could solder a bigger memory chip to the calculator board. I'm not sure why this isn't possible, I just assume it isn't, otherwise people would have done this already.

EDIT: You made me interested to check different material balances that I might learn about next year. The Walsh Formulation is a single equation with (at least) 43 pieces and is used for the material balance of a volatile oil. I haven't used this equation yet, so it could be more complex than that but that's what I counted. It is at the bottom of that page I linked at fekete.com, but it is split into 3 pieces. The reason they do that is to make it more manageable (and to linearize it), but really as a single equation it would have over 40 variables (some repeating). I haven't learned the equation yet, but it would take the form F = Eg*N*m + Eo*N (based on my knowledge of the general MBE), and the F, Eg, and Eo terms would be those long equations near the bottom of the page.