I've been looking for a good formula to calculate the inductance of a multilayer solenoid within about 10% accuracy or greater. I've used several formulas derived from Wheeler's formula, as well as a few online calculators, however, my results seem to differ wildly depending on what formula or calculator I use. I'm wondering if anyone has a formula or calculator for multilayer coils consisting of only a few layers that they've found works well. If it helps the wire is .225 millimeters in diameter, the coils are less than 2 cm long with maybe 2 or three layers, and the diameter of the tubing is 5 millimeters. Thanks!
A couple of years ago you asked about Nagaoka's coefficient, and I directed you to David Knight's web site. You can find a lot of inductance formulas in this document on his site: http://www.g3ynh.info/zdocs/refs/NBS/Sci169noerr.pdf You should buy a copy of this classic book which has tables and formulas for many cases: http://www.amazon.com/Inductance-Ca...ance+calculations+working+formulas+and+tables
The inductance will be critically dependent on the core material, core topology and frequency of operation. Until those three parameters are specified it will be impossible to answer the question. Get a copy of that book. It is essential and cheap new, with free postage. US$15. http://www.bookdepository.com/Induc...nt=Inductance-Calculations&selectCurrency=AUD