Human/hybrid/wingsail powered tri-powered boat in need of help.

Discussion in 'Boat Design' started by fusioneng, Jul 2, 2018.

  1. fusioneng
    Joined: Apr 2013
    Posts: 14
    Likes: 1, Points: 3, Legacy Rep: 26
    Location: sarasota,fl

    fusioneng Junior Member

    I built a tri-powered boat and have been using it about 5-6 yrs now, with no issues, however I'm ready to improve the design, performance, and switch from hybrid gas supplemental propulsion to battery/solar/electric, and hopefully replace the mainsail with a jointed wing.
    First off I have zero desire to to use sail power as my primary propulsion. I'm handicapped and can only go out in winds 3-7mph, and flat seas (which is 80% of the time here in Sarasota FL).

    Obviously weather can hit you anytime, so the boat itself (based on a Hobie Tandem Island) is fully hardened and offshore capable up to 4-5ft seas, and handles 25mph winds easily, just in case, in that situation I revert to conventional sailing, I never go into such conditions on purpose.

    The purpose of the boat is touring and destination sailing, (we were scuba divers, and liked to dive the coral reefs off key west mostly, (where we have another home), however now being handicapped with a bad back, (only in the last 6 months), we may not be doing the diving thing so much anymore, so it will be mostly touring in very low winds.

    The current setup has a cruise speed of 8-10 mph, (in 3-7mph winds), with the best point of sail upwind, (around 20deg off the wind, utilizing apparent wind). The worst point of sail being a broad reach, where the boat reverts to conventional sailing.
    Fuel economy, (averaged over 5 yrs of use) is 60-80 mpg, basically it costs me about a buck to go sailing for the day. I have twin modified Honda 2.3 outboards with custom built high pitch props installed, each tank holds 1 liter of fuel and I get around 3 hrs run time per tank of fuel, (the motors run just above idle, (very quiet), propelling the boat to around 7-8 mph with no wind or sails up, (the power output of each motor is around 3/4hp). The current setup has a 100 mile per day range, (10mph x 10 hrs = 100 mile range). Obviously with more wind the boat goes faster, I have up to 250 sq ft of sail available, (but that's more for conventional sailing).
    The hull has been modified to a planing type hull, (similar to a WETA trimaran), with the bowsprit the modified boat is 21ft long and 12.5 ft wide. The regular Hobie furlable mainsail is 90 sq ft, our Asymmetric furlable wing jib is 33 sq ft, and our Asymmetric furlable spinnaker is around 125 sq ft.

    I'm at a point now where I want to replace the gas outboards with twin 403 Torqeedo electrics, with twin 150 watt solar panels, (one on each tramp). However I need to increase the efficiency of the mainsail rig. I want to build a jointed wing mainsail. But it will only be used as an apparent wind amplifier, upwind, (around 20 deg off the wind) in very low wind conditions, (3-7mph wind). Not really used for primary propulsion at all. It's a human powered pedal boat with two mirage drives primarily, with some supplimental propulsion, (gas or electric), generating your initial forward speed. Then the wing and sails, amplify that apparent wind to make the boat go faster, putting less load on my legs, and the gas or electric drives. The wing and current sail work more as energy amplifiers than sails, (kinda like an air conditioner works).
    I'm looking for a jointed wing design to replace my current mainsail, that provides some type of power amplification from my forward motion. As an example currently if I'm sailing upwind 15-20 degrees off wind in 8 mph winds, and the boat is traveling at 10 mph, the wind on my face is 18 mph. I want to be able to utilize that apparent wind better. I've designed several wings on the drawing board, based on different wing designs, but realized my wing will be working on completely different principles, (not as primary propulsion). So I'm kinda stuck, this is new ground, I'm pretty sure nobody has done this before.
    Just wondering if anyone has thought this thru, (using the jointed wing as an energy amplifier).
    My ultimate goal is 12-14 mph cruise speed, solar/battery/electric propulsion with unlimited range, (as long as the sun is shining).
    I have all that now, (been running with no issues for 5-6 yrs), but my cruise speed is only 8-10 mph, and my range is only a couple hundred miles, plus I want to dump the Hybrid gas motors.
    Any help on the wing sail theory specifically to this apparent wind amplification theory would be tremendously helpful. Therein lies the rub, all regular wing designs are for primary sail propulsion only, ( I have absolutely zero interest in that, (been there done that)).
     
  2. fusioneng
    Joined: Apr 2013
    Posts: 14
    Likes: 1, Points: 3, Legacy Rep: 26
    Location: sarasota,fl

    fusioneng Junior Member

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