Hansen Sails Compliant Leech

Hansen Sails Compliant Leech

Post by barryxw.. » Fri, 13 Oct 2006 02:38:08


Such a simple idea -- using neoprene in the leech to allow the leech to
flex open and relax closed as needed -- why didn't someone think of
this sooner? Actually I believe Bill played around with this quite a
while back. [How long ago, Bill?] Now he's onto something and getting
it patented. You can read the blurb at the URL below [with a photo of
Mike Percy sailing Dr. Doug's proto]. I've also pasted the text below.
And if you're wondering, no hydrochloric acid [HCl] was used to kill or
torture any neoprenes used to develope this technology...
-Barry 'NM-0'

----------------

http://www.hansensails.com/News

----------------

Subject: Compliant Sail Technology
Date: October 9, 2006

Hansen Sails, LLC is pleased to introduce its new Hansen Compliant
Leech technology (HCL.)

HCL is the result of considerable testing and development and provides
a major improvement in performance by allowing a sail to automatically
adjust its shape and twist according to the aerodynamic pressures
encountered. In the case of boardsailing, HCL is particularly
significant because few on-the-fly changes to a sail's tuning can be
made other than outhaul which primarily controls draft in the lower
sections of the sail. The overall shape and twist in the key upper
sections are pre-set during rigging and cannot be controlled under way.
Also, significant distortion is caused by the resilient bending of the
mast under changing loads. For modern truncated tip planforms, it is
well-known that the optimal twist and shape is highly variable
depending on the course sailed and wind and water conditions. As such,
a pre-determined setting which cannot be actively changed is a
compromise in all but a few specific conditions. HCL solves these
problems by providing a full shape with minimal twist which
progressively flattens and twists off as the wind builds through the
judicious placement of elastic 'flex panels' in the sail body. The HCL
technology also includes an on-the-fly compliance adjustability
function for additional tuning and range.

In use, an HCL equipped sail automatically adjusts its shape in gusts
and turbulent conditions and as the sheeting angle varies during
maneuvering and course changes such as reaching or running. In
engineering terms, HCL matches the compliance of the sail to changes in
aerodynamic force. The result is an effective moderation of the
velocity squared aerodynamic forces as well as the relationship between
sheeting angle and force. HCL thus provides a much greater
time-averaged coupling of the sail to the wind for improved performance
and handling. In testing, notable improvements include low-end power
and acceleration, upwind VMG, delayed stall, gust absorption and ease
in handling while turning off the wind, jibing or water starting. HCL
also provides a wider range of effective sheeting angles and an
extremely smooth ride which eliminates much of the fatigue associated
with high-performance sailing. Other added benefits include simplified
rigging and improved mast compatibility as the sail's shape and twist
is less dependent on rig tension and mast flex.

In yachting, where rig motion in a seaway or turbulent air cause rapid
shifts in velocity and sheeting angle, HCL provides immediate reactive
micro-adjustments which are otherwise impossible due to the critical
lag between input and active human response. The result is an average
increase in drive per unit time which is of use in either a competitive
racing or cruising environment. Additional benefits include
simplification of sail control equipment and reduction of shock loading
on the rig and hull for improved reliability and safety. Certain
aspects of HCL technology are also applicable to other aerodynamic or
hydrodynamic devices.

Hansen Sails, LLC is actively pursuing a utility patent regarding this
technology and anticipates licensing those interested. For further

 
 
 

Hansen Sails Compliant Leech

Post by josh.sampi.. » Fri, 13 Oct 2006 02:53:14

Guys,

 Look forward to some bonus coverage on  the new Hansen sail w/ the
neoprene leech in the next e-newsletter ...

If you don't get our e-newsletter, sign up at www.windsurfingmag.com.

- josh


Quote:
> Such a simple idea -- using neoprene in the leech to allow the leech to
> flex open and relax closed as needed -- why didn't someone think of
> this sooner? Actually I believe Bill played around with this quite a
> while back. [How long ago, Bill?] Now he's onto something and getting
> it patented. You can read the blurb at the URL below [with a photo of
> Mike Percy sailing Dr. Doug's proto]. I've also pasted the text below.
> And if you're wondering, no hydrochloric acid [HCl] was used to kill or
> torture any neoprenes used to develope this technology...
> -Barry 'NM-0'

> ----------------

> http://www.hansensails.com/News

> ----------------

> Subject: Compliant Sail Technology
> Date: October 9, 2006

> Hansen Sails, LLC is pleased to introduce its new Hansen Compliant
> Leech technology (HCL.)

> HCL is the result of considerable testing and development and provides
> a major improvement in performance by allowing a sail to automatically
> adjust its shape and twist according to the aerodynamic pressures
> encountered. In the case of boardsailing, HCL is particularly
> significant because few on-the-fly changes to a sail's tuning can be
> made other than outhaul which primarily controls draft in the lower
> sections of the sail. The overall shape and twist in the key upper
> sections are pre-set during rigging and cannot be controlled under way.
> Also, significant distortion is caused by the resilient bending of the
> mast under changing loads. For modern truncated tip planforms, it is
> well-known that the optimal twist and shape is highly variable
> depending on the course sailed and wind and water conditions. As such,
> a pre-determined setting which cannot be actively changed is a
> compromise in all but a few specific conditions. HCL solves these
> problems by providing a full shape with minimal twist which
> progressively flattens and twists off as the wind builds through the
> judicious placement of elastic 'flex panels' in the sail body. The HCL
> technology also includes an on-the-fly compliance adjustability
> function for additional tuning and range.

> In use, an HCL equipped sail automatically adjusts its shape in gusts
> and turbulent conditions and as the sheeting angle varies during
> maneuvering and course changes such as reaching or running. In
> engineering terms, HCL matches the compliance of the sail to changes in
> aerodynamic force. The result is an effective moderation of the
> velocity squared aerodynamic forces as well as the relationship between
> sheeting angle and force. HCL thus provides a much greater
> time-averaged coupling of the sail to the wind for improved performance
> and handling. In testing, notable improvements include low-end power
> and acceleration, upwind VMG, delayed stall, gust absorption and ease
> in handling while turning off the wind, jibing or water starting. HCL
> also provides a wider range of effective sheeting angles and an
> extremely smooth ride which eliminates much of the fatigue associated
> with high-performance sailing. Other added benefits include simplified
> rigging and improved mast compatibility as the sail's shape and twist
> is less dependent on rig tension and mast flex.

> In yachting, where rig motion in a seaway or turbulent air cause rapid
> shifts in velocity and sheeting angle, HCL provides immediate reactive
> micro-adjustments which are otherwise impossible due to the critical
> lag between input and active human response. The result is an average
> increase in drive per unit time which is of use in either a competitive
> racing or cruising environment. Additional benefits include
> simplification of sail control equipment and reduction of shock loading
> on the rig and hull for improved reliability and safety. Certain
> aspects of HCL technology are also applicable to other aerodynamic or
> hydrodynamic devices.

> Hansen Sails, LLC is actively pursuing a utility patent regarding this
> technology and anticipates licensing those interested. For further



 
 
 

Hansen Sails Compliant Leech

Post by Dan Weis » Fri, 13 Oct 2006 04:44:36

At the risk of being accused of tossing out historical minutia, Dave
Ezzy used neoprene at the very top of the leech (at the head) in his
mid-90s race sails.  I think they were named Transformer.  The basic
idea was the same, but done using a very different concept and without
incorporating the material into different sections of the sail -or even
into the sail's body as Bill Hansen has done.

Pretty cool idea, however it turns out.  I'd love to sail one.  I
suspect we might see more of this sort of concept as auto-trim sails
are always the goal.

Awesome!

-Dan

Quote:

> Guys,

>  Look forward to some bonus coverage on  the new Hansen sail w/ the
> neoprene leech in the next e-newsletter ...

> If you don't get our e-newsletter, sign up at www.windsurfingmag.com.

> - josh


> > Such a simple idea -- using neoprene in the leech to allow the leech to
> > flex open and relax closed as needed -- why didn't someone think of
> > this sooner? Actually I believe Bill played around with this quite a
> > while back. [How long ago, Bill?] Now he's onto something and getting
> > it patented. You can read the blurb at the URL below [with a photo of
> > Mike Percy sailing Dr. Doug's proto]. I've also pasted the text below.
> > And if you're wondering, no hydrochloric acid [HCl] was used to kill or
> > torture any neoprenes used to develope this technology...
> > -Barry 'NM-0'

> > ----------------

> > http://www.hansensails.com/News

> > ----------------

> > Subject: Compliant Sail Technology
> > Date: October 9, 2006

> > Hansen Sails, LLC is pleased to introduce its new Hansen Compliant
> > Leech technology (HCL.)

> > HCL is the result of considerable testing and development and provides
> > a major improvement in performance by allowing a sail to automatically
> > adjust its shape and twist according to the aerodynamic pressures
> > encountered. In the case of boardsailing, HCL is particularly
> > significant because few on-the-fly changes to a sail's tuning can be
> > made other than outhaul which primarily controls draft in the lower
> > sections of the sail. The overall shape and twist in the key upper
> > sections are pre-set during rigging and cannot be controlled under way.
> > Also, significant distortion is caused by the resilient bending of the
> > mast under changing loads. For modern truncated tip planforms, it is
> > well-known that the optimal twist and shape is highly variable
> > depending on the course sailed and wind and water conditions. As such,
> > a pre-determined setting which cannot be actively changed is a
> > compromise in all but a few specific conditions. HCL solves these
> > problems by providing a full shape with minimal twist which
> > progressively flattens and twists off as the wind builds through the
> > judicious placement of elastic 'flex panels' in the sail body. The HCL
> > technology also includes an on-the-fly compliance adjustability
> > function for additional tuning and range.

> > In use, an HCL equipped sail automatically adjusts its shape in gusts
> > and turbulent conditions and as the sheeting angle varies during
> > maneuvering and course changes such as reaching or running. In
> > engineering terms, HCL matches the compliance of the sail to changes in
> > aerodynamic force. The result is an effective moderation of the
> > velocity squared aerodynamic forces as well as the relationship between
> > sheeting angle and force. HCL thus provides a much greater
> > time-averaged coupling of the sail to the wind for improved performance
> > and handling. In testing, notable improvements include low-end power
> > and acceleration, upwind VMG, delayed stall, gust absorption and ease
> > in handling while turning off the wind, jibing or water starting. HCL
> > also provides a wider range of effective sheeting angles and an
> > extremely smooth ride which eliminates much of the fatigue associated
> > with high-performance sailing. Other added benefits include simplified
> > rigging and improved mast compatibility as the sail's shape and twist
> > is less dependent on rig tension and mast flex.

> > In yachting, where rig motion in a seaway or turbulent air cause rapid
> > shifts in velocity and sheeting angle, HCL provides immediate reactive
> > micro-adjustments which are otherwise impossible due to the critical
> > lag between input and active human response. The result is an average
> > increase in drive per unit time which is of use in either a competitive
> > racing or cruising environment. Additional benefits include
> > simplification of sail control equipment and reduction of shock loading
> > on the rig and hull for improved reliability and safety. Certain
> > aspects of HCL technology are also applicable to other aerodynamic or
> > hydrodynamic devices.

> > Hansen Sails, LLC is actively pursuing a utility patent regarding this
> > technology and anticipates licensing those interested. For further



 
 
 

Hansen Sails Compliant Leech

Post by sm.. » Fri, 13 Oct 2006 05:24:03

Interesting concept.

I would like to see how the on-the-fly compliance adjustability
function is incorporated.  Is it a leech line of some sort?

Also, I would be interested to see how the system works when used with
"yacht" sails, as the write-up states.  Nearly all boats sail with
considerably higher leech loads compared to windsurfers, particularly
when sailing upwind.  I would think that neoprene leech panels would
stretch too much when high mainsheet or vang load is applied.  Maybe
he's got a deflection limiter built in to the sail that only lets the
leech stretch so far.

In any case, I look forward to seeing what comes of this.

sm

Quote:

> Such a simple idea -- using neoprene in the leech to allow the leech to
> flex open and relax closed as needed -- why didn't someone think of
> this sooner? Actually I believe Bill played around with this quite a
> while back. [How long ago, Bill?] Now he's onto something and getting
> it patented. You can read the blurb at the URL below [with a photo of
> Mike Percy sailing Dr. Doug's proto]. I've also pasted the text below.
> And if you're wondering, no hydrochloric acid [HCl] was used to kill or
> torture any neoprenes used to develope this technology...
> -Barry 'NM-0'

> ----------------

> http://www.hansensails.com/News

> ----------------

> Subject: Compliant Sail Technology
> Date: October 9, 2006

> Hansen Sails, LLC is pleased to introduce its new Hansen Compliant
> Leech technology (HCL.)

> HCL is the result of considerable testing and development and provides
> a major improvement in performance by allowing a sail to automatically
> adjust its shape and twist according to the aerodynamic pressures
> encountered. In the case of boardsailing, HCL is particularly
> significant because few on-the-fly changes to a sail's tuning can be
> made other than outhaul which primarily controls draft in the lower
> sections of the sail. The overall shape and twist in the key upper
> sections are pre-set during rigging and cannot be controlled under way.
> Also, significant distortion is caused by the resilient bending of the
> mast under changing loads. For modern truncated tip planforms, it is
> well-known that the optimal twist and shape is highly variable
> depending on the course sailed and wind and water conditions. As such,
> a pre-determined setting which cannot be actively changed is a
> compromise in all but a few specific conditions. HCL solves these
> problems by providing a full shape with minimal twist which
> progressively flattens and twists off as the wind builds through the
> judicious placement of elastic 'flex panels' in the sail body. The HCL
> technology also includes an on-the-fly compliance adjustability
> function for additional tuning and range.

> In use, an HCL equipped sail automatically adjusts its shape in gusts
> and turbulent conditions and as the sheeting angle varies during
> maneuvering and course changes such as reaching or running. In
> engineering terms, HCL matches the compliance of the sail to changes in
> aerodynamic force. The result is an effective moderation of the
> velocity squared aerodynamic forces as well as the relationship between
> sheeting angle and force. HCL thus provides a much greater
> time-averaged coupling of the sail to the wind for improved performance
> and handling. In testing, notable improvements include low-end power
> and acceleration, upwind VMG, delayed stall, gust absorption and ease
> in handling while turning off the wind, jibing or water starting. HCL
> also provides a wider range of effective sheeting angles and an
> extremely smooth ride which eliminates much of the fatigue associated
> with high-performance sailing. Other added benefits include simplified
> rigging and improved mast compatibility as the sail's shape and twist
> is less dependent on rig tension and mast flex.

> In yachting, where rig motion in a seaway or turbulent air cause rapid
> shifts in velocity and sheeting angle, HCL provides immediate reactive
> micro-adjustments which are otherwise impossible due to the critical
> lag between input and active human response. The result is an average
> increase in drive per unit time which is of use in either a competitive
> racing or cruising environment. Additional benefits include
> simplification of sail control equipment and reduction of shock loading
> on the rig and hull for improved reliability and safety. Certain
> aspects of HCL technology are also applicable to other aerodynamic or
> hydrodynamic devices.

> Hansen Sails, LLC is actively pursuing a utility patent regarding this
> technology and anticipates licensing those interested. For further


 
 
 

Hansen Sails Compliant Leech

Post by hanse » Fri, 13 Oct 2006 06:08:22

SM:
Yes, it is a leech line system with adjustable spring constant and an
optional controllable limiting provision. In the case of yachts, what
you say is true regarding the role of leech tension, etc. However, the
trend in yachting, despite a highly conservative traditionalist
mentality, is toward 'windsurfing technology' rather than away. This is
evident in larger and larger 'chop top' mains, more easily driven
planing hulls, higher speeds in rough water and the growing popularity
of unstayed uni-rigs like the Wyliecats. The key is compliance matching
- at any scale - a basic engineering concept which IMHO, the yachting
community needs to think more about unless they want to keep losing
rigs overboard and spending container loads of money for a few extra
knots...
Quote:

> Interesting concept.
> I would like to see how the on-the-fly compliance adjustability
> function is incorporated.  Is it a leech line of some sort?
> Also, I would be interested to see how the system works when used with
> "yacht" sails, as the write-up states.  Nearly all boats sail with
> considerably higher leech loads compared to windsurfers, particularly
> when sailing upwind.  I would think that neoprene leech panels would
> stretch too much when high mainsheet or vang load is applied.  Maybe
> he's got a deflection limiter built in to the sail that only lets the
> leech stretch so far.
> In any case, I look forward to seeing what comes of this.
> sm