mothematics.blogspot.com
Mothematics: April 2009
http://mothematics.blogspot.com/2009_04_01_archive.html
Sunday, April 12, 2009. How much energy does sailing in chop take? It does seem like filtering out the high-frequency could be a good idea.all the extra work has to be slowing the boat down. But any filter will slow the response (e.g. to sharp waves) down so there will be some optimization. Just need to figure out a way to implement filters without op-amps and batteries. Labels: chop response moth math model. Monday, April 6, 2009. If one is good, are two better? The poor performance of elevator control ...
mothematics.blogspot.com
Mothematics: Elevator or Flap Control?
http://mothematics.blogspot.com/2009/03/for-height-control-on-foiling-moth.html
Sunday, March 29, 2009. Elevator or Flap Control? For height control on a foiling Moth the usual practice to to control the AOA and CL of the main foil with a flap connected to a wand that senses the height of the boat. One question is whether elevator control, i.e. use the rear foil to change the pitch of the main foil, is viable alternative. This is how airplanes control the AOA and maintain level flight. I used the stability model (from alans of AUS) to compare elevator control to flap control. Also i...
mothematics.blogspot.com
Mothematics: March 2009
http://mothematics.blogspot.com/2009_03_01_archive.html
Sunday, March 29, 2009. Elevator or Flap Control? For height control on a foiling Moth the usual practice to to control the AOA and CL of the main foil with a flap connected to a wand that senses the height of the boat. One question is whether elevator control, i.e. use the rear foil to change the pitch of the main foil, is viable alternative. This is how airplanes control the AOA and maintain level flight. I used the stability model (from alans of AUS) to compare elevator control to flap control. I used...
mothematics.blogspot.com
Mothematics: If one is good, are two better?
http://mothematics.blogspot.com/2009/04/if-one-is-good-are-two-better.html
Monday, April 6, 2009. If one is good, are two better? The poor performance of elevator control led me to try some other schemes. Leaving out the ones that did not work, the above graph compares the response of a flap only control scheme to a scheme that moves the elevator in the same direction as the flap, but at half the gain. It is not clear that this is a better scheme but it does get all the control forces acting in the direction that the boat wants to move when the wand senses the trough.
mothematics.blogspot.com
Mothematics: Moth software (computer variety)
http://mothematics.blogspot.com/2010/01/moth-software-computer-variety.html
Saturday, January 23, 2010. Moth software (computer variety). A couple of pointers to free analysis programs, have not used either package yet. Gleaned from: http:/ moose-moth.blogspot.com/. Who seems to be doing what I originally intended, i.e. designing and building a Moth. AVL ( from Drela at MIT), follow on to Xfoil, extended to include the whole airplane. Http:/ web.mit.edu/drela/Public/web/avl/. Another one based on Xfoil. Http:/ xflr5.sourceforge.net/xflr5.htm. January 24, 2010 at 9:19 AM.
mothematics.blogspot.com
Mothematics: How much energy does sailing in chop take?
http://mothematics.blogspot.com/2009/04/how-much-energy-does-sailing-in-chop.html
Sunday, April 12, 2009. How much energy does sailing in chop take? It does seem like filtering out the high-frequency could be a good idea.all the extra work has to be slowing the boat down. But any filter will slow the response (e.g. to sharp waves) down so there will be some optimization. Just need to figure out a way to implement filters without op-amps and batteries. Labels: chop response moth math model. April 12, 2009 at 11:34 PM. Why does green line start higher and finish lower? Reposted the grap...
mothematics.blogspot.com
Mothematics: Findlay/Turnock VPP from Uni. of Southampton
http://mothematics.blogspot.com/2009/04/findlayturnock-vpp-from-uni-of.html
Friday, April 3, 2009. Findlay/Turnock VPP from Uni. of Southampton. Just in case you have not seen it, this is a link to a paper from Findlay/Turnock on a velocity prediction program written in Basic/Excel. It does a good job explaining the inputs to a VPP and has a nice flow diagram for the logic of the program. Http:/ eprints.soton.ac.uk/52462/01/Findlay Turnock Foil VPP.pdf. Subscribe to: Post Comments (Atom). Flying Moose - International Moth. Video of 3-man foiler. If one is good, are two better?
mothematics.blogspot.com
Mothematics: Accuracy of inputs
http://mothematics.blogspot.com/2009/04/accuracy-of-inputs.html
Thursday, April 2, 2009. We had some off-line discussion about how to get a good moment of inertia for the dynamics model. Bifilar pendulum is a standard way. The Finn class uses the Lamboley swing method which can be found here ( www.lamboleyetudes.net. I decided to run the model with /- 50% pitch inertia change from Alan's original estimate of 20 slug-ft-ft to see if it is sensitive to inertia changes. April 3, 2009 at 12:41 AM. Does centre of rotation influence these calcs? April 3, 2009 at 7:28 AM.
mothematics.blogspot.com
Mothematics: What does wand lead do (AKA midship wand)?
http://mothematics.blogspot.com/2009/03/alan-s.html
Friday, March 27, 2009. What does wand lead do (AKA midship wand)? An internet friend gave me his stability model, which is based on using Runge-Kutta integration on the equations of motion (i.e. F= ma, etc). I used it to do some parameter studies for the response of a flying Moth to holes in the water. First conclusion is that more wand lead is good. Labels: Moth midship wand. December 29, 2010 at 3:58 PM. Subscribe to: Post Comments (Atom). Flying Moose - International Moth. Video of 3-man foiler.