Author Topic: Under 1 meter blade design problem  (Read 201 times)

0 Members and 1 Guest are viewing this topic.

ghurd

  • Super Hero Member Plus
  • *******
  • Posts: 8059
Under 1 meter blade design problem
« on: February 27, 2005, 02:16:39 PM »
I decided to try a wooden 2 foot dia 3 blade TSR of 5-ish.

Using the common free download design programs I seem to have found a bug in all of them I tried.


Anything under 1 meter throws them for a loop.  As the blade gets smaller, things get farther off.  Things like a 0.2 meter blade making 525 watts in a 10MPH wind, or a 0.3 meter getting 1900% efficiency at 10MPH.


The designed blade each program shows seems quite different than any of the other programs.


I honestly don't know enough to know which is close and which is way off.  I do know 0.2m in 10MPH will not get 525W.  I also know I, personally, can not carve a blade with the last 2 stations 1mm or less thick.


Any suggestions?  I'm not concerned with the watts (it illustrates the bug), just the blades.


Thanks,

G-

« Last Edit: February 27, 2005, 02:16:39 PM by (unknown) »
www.ghurd.info<<<-----Information on my Controller

windstuffnow

  • Hero Member
  • *****
  • Posts: 1065
  • Country: 00
Re: Under 1 meter blade design problem
« Reply #1 on: February 27, 2005, 07:35:42 AM »
  Mine shows 1 watt in a 10mph wind using a .3m blade with a TSR of 5.  A 2ft blade at around 5 watts in a 10mph wind running roughly around 700 rpm.  The tip thickness is at .16"


  I wonder how they set up thier formulas....


Windstuff Ed

« Last Edit: February 27, 2005, 07:35:42 AM by windstuffnow »
Windstuff Ed

ghurd

  • Super Hero Member Plus
  • *******
  • Posts: 8059
Re: Under 1 meter blade design problem
« Reply #2 on: February 27, 2005, 08:14:49 AM »
Sold!

G-
« Last Edit: February 27, 2005, 08:14:49 AM by ghurd »
www.ghurd.info<<<-----Information on my Controller

ghurd

  • Super Hero Member Plus
  • *******
  • Posts: 8059
Re: Under 1 meter blade design problem
« Reply #3 on: February 27, 2005, 11:43:23 AM »
It works great!

Produces a blade I can understand (and make), even with the 'unusual', less than 1 meter, numbers entered.

Sure worth $5.  It will save me more in sandpaper than that.

Thanks Ed,

G-
« Last Edit: February 27, 2005, 11:43:23 AM by ghurd »
www.ghurd.info<<<-----Information on my Controller