Does water temperature affect fin performance?

Discussion in 'Surfboards and Surfboard Design' started by Roy Stuart, Oct 12, 2015.

Page 3 of 7
  1. Oct 12, 2015 #41
    Towelie

    Towelie Well-Known Member

    2,864
    Nov 27, 2014
    which is, again, minuscule.
     
    Towelie, Oct 12, 2015
    Towelie, Oct 12, 2015
  3. Oct 12, 2015 #42
    Towelie

    Towelie Well-Known Member

    2,864
    Nov 27, 2014
    .
     
    Towelie, Oct 12, 2015
    Towelie, Oct 12, 2015

  5. Oct 12, 2015 #43
    Towelie

    Towelie Well-Known Member

    2,864
    Nov 27, 2014
    besides:

    "Chord width 0.06 m 0.19685 ft 2.3622 in" are you insane? measure a fin's width and come back.
     
    Towelie, Oct 12, 2015
    Towelie, Oct 12, 2015
  6. Oct 12, 2015 #44
    Roy Stuart

    Roy Stuart Well-Known Member

    1,514
    Jan 27, 2013
    It certainly is not miniscule.

    As I've stated already, the magnitude of the difference in the reynolds number is similar to the change over the range of typical surfing speeds experienced... and as we know that is certainly significant.

    Take a look at the graphs shown, the change in angle of attack capability for the fin shown is large, as is the difference in drag.

    Regarding the 60mm chord, it's on the low side and was chosen simply because the Reynolds number calculator I'm using tops out at 1,000,000 .... using a bigger chord thus wouldn't allow the full difference to be shown. The results with a narrow chord are also interesting because they might indicate that narrower chords can be used ( an advantage if they do the job since they are more efficient) if one is prepared to use closer tolerances in terms of minimum fin size. Doing so will probably require that a longer chord is needed in colder water, all else being equal.

    At present the one size fits all approach which covers cold and warm water means that a longer chord than is necessary is being employed in warm water.

    By the way I have two boards which use a 60mm fin chord on the main fin, and several side fins which have a similar chord. Admittedly the side fins use leading edge bumps, which greatly increase the angle of attack capability, but the fins without the bumps also work well.

    .

    .
     
    Last edited: Oct 12, 2015
    Roy Stuart, Oct 12, 2015
    Roy Stuart, Oct 12, 2015
  7. Oct 12, 2015 #45
    Mr.Belmar

    Mr.Belmar Well-Known Member

    3,824
    Aug 19, 2010
    Hard to notice while wearing the extra thicke wetsuite

    Good job guys.
     
    Mr.Belmar, Oct 12, 2015
    Mr.Belmar, Oct 12, 2015
  8. Oct 12, 2015 #46
    EMazzSpicoli

    EMazzSpicoli Well-Known Member

    182
    Jul 1, 2015
    Ruoy, is your snake oil crude like diesel or is it refined?
     
    EMazzSpicoli, Oct 12, 2015
    EMazzSpicoli, Oct 12, 2015
  9. Oct 12, 2015 #47
    Roy Stuart

    Roy Stuart Well-Known Member

    1,514
    Jan 27, 2013
    Not necessarily since one of the consequences could be fin spinout.
     
    Roy Stuart, Oct 12, 2015
    Roy Stuart, Oct 12, 2015
  10. Oct 12, 2015 #48
    Roy Stuart

    Roy Stuart Well-Known Member

    1,514
    Jan 27, 2013
    Physics old sport.
     
    Roy Stuart, Oct 12, 2015
    Roy Stuart, Oct 12, 2015
  11. Oct 12, 2015 #49
    Mr.Belmar

    Mr.Belmar Well-Known Member

    3,824
    Aug 19, 2010
    So I gotta ask (sorry guys):

    So what kinda fins should I ride?

    There... I said it...
     
    Mr.Belmar, Oct 12, 2015
    Mr.Belmar, Oct 12, 2015
  12. Oct 12, 2015 #50
    Roy Stuart

    Roy Stuart Well-Known Member

    1,514
    Jan 27, 2013
    That's a moral question, to which I don't know the answer. ;)
     
    Roy Stuart, Oct 12, 2015
    Roy Stuart, Oct 12, 2015
  13. Oct 12, 2015 #51
    sisurfdogg

    sisurfdogg Well-Known Member

    5,399
    Jun 17, 2013
    It's elementary, dear Watson. Cold water induces shrinkage. Therefore, insulative material needs to be added to the molecular matrix which will greatly mitigate the affects of frigid temps on the projecting fin(s) (aka:the wool sock effect).
     
    sisurfdogg, Oct 12, 2015
    sisurfdogg, Oct 12, 2015
  14. Oct 12, 2015 #52
    sisurfdogg

    sisurfdogg Well-Known Member

    5,399
    Jun 17, 2013
    Just breaking it down for the laymen.
     
    sisurfdogg, Oct 12, 2015
    sisurfdogg, Oct 12, 2015
  15. Oct 12, 2015 #53
    252surfer

    252surfer Well-Known Member

    1,280
    Dec 1, 2010
    so if i put a wool sock on my cock during the winter, the wool sock effect won't happen to me??
     
    252surfer, Oct 12, 2015
    252surfer, Oct 12, 2015
  16. Oct 12, 2015 #54
    waterbaby

    waterbaby Well-Known Member

    1,461
    Oct 1, 2012
    a-ha, now I see the inspiration for your surfboard shapes:

    [​IMG]
     
    waterbaby, Oct 12, 2015
    waterbaby, Oct 12, 2015
  17. Oct 12, 2015 #55
    sisurfdogg

    sisurfdogg Well-Known Member

    5,399
    Jun 17, 2013
    The Wool Sock Effect is a beneficial phenomena induced by the introduction of insulative material to reduce dreaded shrinkage. Let's not confuse things here.
     
    sisurfdogg, Oct 12, 2015
    sisurfdogg, Oct 12, 2015
  18. Oct 12, 2015 #56
    Roy Stuart

    Roy Stuart Well-Known Member

    1,514
    Jan 27, 2013
    You are 100% correct, most of them have been based on foil shapes since 1996.
     
    Roy Stuart, Oct 12, 2015
    Roy Stuart, Oct 12, 2015
  19. Oct 12, 2015 #57
    sisurfdogg

    sisurfdogg Well-Known Member

    5,399
    Jun 17, 2013
    This idea sounds like money! Has it ever been tried before? Comfort and performance enhanced with a photovoltaic cell and some coiled wire. Delam could be an issue.
     
    sisurfdogg, Oct 12, 2015
    sisurfdogg, Oct 12, 2015
  20. Oct 13, 2015 #58
    kidrock

    kidrock Well-Known Member

    2,042
    Aug 1, 2010
    There, I fixed it for you brah
     
    kidrock, Oct 13, 2015
    kidrock, Oct 13, 2015
  21. Oct 13, 2015 #59
    EMazzSpicoli

    EMazzSpicoli Well-Known Member

    182
    Jul 1, 2015
    So from this valuable treade, I've deduced the following:

    1) Stock up on wool socks. Even though I head west to CA for good in two days. The woolen sheathe shall set me free when water dips to low 60s.

    2) Ruoy's doucherie is like fine wine - he gets to be more of a stiffe with each next day.
     
    EMazzSpicoli, Oct 13, 2015
    EMazzSpicoli, Oct 13, 2015
  22. Oct 13, 2015 #60
    EMazzSpicoli

    EMazzSpicoli Well-Known Member

    182
    Jul 1, 2015
    Bleffe's wool
     
    EMazzSpicoli, Oct 13, 2015
    EMazzSpicoli, Oct 13, 2015
Page 3 of 7