powerHull resistance

This is Windows based application to perform resistance/powering analysis for power boats.

Current features include:
- Bare hull resistance prediction
- Appendage resistance estimation (rudders, shafts, struts, trim-tabs)
- Air drag estimation
- Adding resistance margin
- Setting overall propulsion efficiency and transmission loss for estimating total required power
- storing/retrieving parameter files
- Metric/Imperial units

Currently implemented methods:
- Original Savitsky method including whisker spray resistance, lift and drag from trim tabs, porpoising stability assesment for prismatic planing hulls
- Modified Savitsky with the Blount & Fox M-Factor for hump-speed region
- Mercier & Savitsky for pre-planing speeds of chine hulls with transoms
- Lahtiharju method (chine hulls only)
- Series 62 and Series 65
- Crouch simple method for planing speeds
- Wyman simple method for semi-planing speeds

I hope you can find this work useful and maybe comment here with some feedback regarding improvements and future additions.

 

Hello Vassili,
Thanks for sharing your effort! I checked the software briefly for a couple of known cases and I like the clean appearance, but there are some snatches. The Froude numbers are not calculated correctly for all methods, leading to results seemingly outside the valid range. Also, the corresponding message "..outside of range.." is a bit frustrating when there is no reference to actual numbers for the acceptable range.

 

Thank you for your comments. There was indeed a bug in the Froude numbers calculated for the Savitsky based methods. Fixed in the build 270422 posted below. Some of the methods use "no straight-forward" ratios as boundary limits thus I decided not to show them to the user to keep it as simple as possible. I may find a way to view them though if you feel it is helpful.

You can uninstall your current version and install the new one as with any other application.

 

This is a an updated version (build 270422) of the powerHull application.

Fixes a bug with the Froude number calculations for the Savitsky based methods.