Technology and Operations
This forum is for discussing technological & operational matters pertaining to U-boats.
By calculation
Posted by:
SuperKraut
()
Date: January 16, 2001 09:42PM
Speed is related to fuel consumption by a square factor. Doubling the speed increases fuel consumption by a factor of 4. If you have range at a given speed, you can get a good estimate of the range at other speeds by applying the equation: r2 times the square root of v1/v2 equals r1. This will work nicely for operation with Diesel engines. This formula is not 100% accurate because the drag coefficient varies with speed.
Battery performance is a more complex issue because the total power available in the battery is a function of the discharge rate. U-boat batteries only gave roughly 35% of their rated power (100 hr discharge) if discharged over 1 hour. The curve is not linear and the efficiency drops off rather rapidly if the discharge is less than 10 hrs. It gets even more complicated because a rapidly discharged battery will \"bounce back\" after a while and produce quite a bit of power at a low discharge rate. Another complicating factor is that the submerged U-boat uses electricity for other purposes than propulsion, so there is a base line load which must be considered. In fact, at low speed, the base line load can be higher than the propulsion load.
Having said all this, I too would be interested in seeing the actual battery performance curves myself. I am working with approximate data.
Regards,
SuperKraut
Battery performance is a more complex issue because the total power available in the battery is a function of the discharge rate. U-boat batteries only gave roughly 35% of their rated power (100 hr discharge) if discharged over 1 hour. The curve is not linear and the efficiency drops off rather rapidly if the discharge is less than 10 hrs. It gets even more complicated because a rapidly discharged battery will \"bounce back\" after a while and produce quite a bit of power at a low discharge rate. Another complicating factor is that the submerged U-boat uses electricity for other purposes than propulsion, so there is a base line load which must be considered. In fact, at low speed, the base line load can be higher than the propulsion load.
Having said all this, I too would be interested in seeing the actual battery performance curves myself. I am working with approximate data.
Regards,
SuperKraut
Subject | Written By | Posted |
---|---|---|
Performance/range | Richard Carr | 01/16/2001 01:40PM |
By calculation | SuperKraut | 01/16/2001 09:42PM |
RE: By calculation | Rainer Bruns | 01/16/2001 10:21PM |
RE: By calculation | Jerry Pope | 01/17/2001 05:49PM |
RE: By calculation | Rainer Bruns | 01/17/2001 06:04PM |
Increasing speed with air bubbles | kurt | 01/17/2001 10:55PM |
RE: Increasing speed with air bubbles | Tom Iwanski | 01/19/2001 03:13AM |
RE: Increasing speed with air bubbles | Don Baker | 01/20/2001 04:17AM |
RE: Increasing speed with air bubbles | kurt | 01/22/2001 05:55PM |
RE: Performance/range | Richard Carr | 01/19/2001 03:52PM |