Request for collaboration
Posted: Mon Dec 10, 2018 1:00 am
I think I know how to work out the passive stability of the elevation angle of an airship used as a sail. I had the idea oever a year ago, but I have other projects, both professional and boat related, with higher priority, so nothing has happened. Is anyone interested in a collaboration? The project requires some knowledge of trigonometry, and in case there is no closed form solution, some programming, though that could possibly be done with an Excel spreadsheet.
I did consider buying a small aerostat for practical experiments, but abandoned that idea the moment I checked the price of helium. When I searched for hydrogen, I only found sites about hydrogen fuels, but none telling me where I could get bottles, and at what price. Also, I doubt the cooperative that owns the house which contains my flat would be happy with me storing a bottle of hydrogen.
I also have two new designs for a hapa that should go well with a sailing airship. My employment contract with my university contains a standard clause which states that the university gets a share in anything I might patent. The Office for Technology Transfer was a bit surprised when someone working in the department of psychology came to them with an idea in marine engineering. They concluded that only one of the designs was patentable, and that the potential market was too small for the university to take an interest.
Being an academic, it would be useful for me if this could be published in an academic journal as well as in Catalyst. The International Journal of Small Craft Technology (https://www.rina.org.uk/ijsct.html) seems suitable. Referencing work previously published in Catalyst might also generate a bit of publicity for AYRS, and I could state as affiliation both my university and AYRS. The likely problem is that academic journals take over copyright, and take a dim view of essentially the same stuff being republished elsewhere. One possible solution is to submit the airship part alone to IJSCT, and publish information on both airship and hapa in Catalyst.
Is anyone interested in getting involved?
I also had an idea regarding hull slewing, as instantiated in Jon Montgomery's Quatrefoil (Catalyst 15). Quatrefoil's beams rotate around vertical axes. Instead, rake them aft, a little, perhaps 5 to 10 degrees. As wind pressure tries to lift the windward hull, that rake in the rotation axis means the hull will swing aft until constrained. It would not be necessary to actively slew the hulls, only to stop them from going too far. In case of capsize, some buoyancy in the masts (I assume a biplane rig) will also make the hulls slew. Remove the limit to let the boat fold up until the hulls touch, and it should come up at least on its side. If the hulls then have a step above the waterline, possibly only on the outside, it might even be possible for the boat to right itself without doing anything more.
What would worry me is a sailor getting caught between beam and hull. The best cure for that which I could think of is to put the net between the hulls up high, at the level of the hulls' decks. My other worry is torsion. As I understand it, resistance to torsion comes partly from the distribution of material in each indicvidual beam, as represented by the moment of inertia around the beam's long axis, and partly from the moment of inertia that comes from the distance between beams. Letting the boat fold up to right itself after a capsize means reducing the distance not only between hulls, but also between beams, at a time when waves will twist the structure. How much extra material would be needed to prevent the beams from breaking?
I am an extremely slow builder, and have other projects before this one. Does anyone want to build a (model) cat with raked rotation axes, and report back on how it works?
I did consider buying a small aerostat for practical experiments, but abandoned that idea the moment I checked the price of helium. When I searched for hydrogen, I only found sites about hydrogen fuels, but none telling me where I could get bottles, and at what price. Also, I doubt the cooperative that owns the house which contains my flat would be happy with me storing a bottle of hydrogen.
I also have two new designs for a hapa that should go well with a sailing airship. My employment contract with my university contains a standard clause which states that the university gets a share in anything I might patent. The Office for Technology Transfer was a bit surprised when someone working in the department of psychology came to them with an idea in marine engineering. They concluded that only one of the designs was patentable, and that the potential market was too small for the university to take an interest.
Being an academic, it would be useful for me if this could be published in an academic journal as well as in Catalyst. The International Journal of Small Craft Technology (https://www.rina.org.uk/ijsct.html) seems suitable. Referencing work previously published in Catalyst might also generate a bit of publicity for AYRS, and I could state as affiliation both my university and AYRS. The likely problem is that academic journals take over copyright, and take a dim view of essentially the same stuff being republished elsewhere. One possible solution is to submit the airship part alone to IJSCT, and publish information on both airship and hapa in Catalyst.
Is anyone interested in getting involved?
I also had an idea regarding hull slewing, as instantiated in Jon Montgomery's Quatrefoil (Catalyst 15). Quatrefoil's beams rotate around vertical axes. Instead, rake them aft, a little, perhaps 5 to 10 degrees. As wind pressure tries to lift the windward hull, that rake in the rotation axis means the hull will swing aft until constrained. It would not be necessary to actively slew the hulls, only to stop them from going too far. In case of capsize, some buoyancy in the masts (I assume a biplane rig) will also make the hulls slew. Remove the limit to let the boat fold up until the hulls touch, and it should come up at least on its side. If the hulls then have a step above the waterline, possibly only on the outside, it might even be possible for the boat to right itself without doing anything more.
What would worry me is a sailor getting caught between beam and hull. The best cure for that which I could think of is to put the net between the hulls up high, at the level of the hulls' decks. My other worry is torsion. As I understand it, resistance to torsion comes partly from the distribution of material in each indicvidual beam, as represented by the moment of inertia around the beam's long axis, and partly from the moment of inertia that comes from the distance between beams. Letting the boat fold up to right itself after a capsize means reducing the distance not only between hulls, but also between beams, at a time when waves will twist the structure. How much extra material would be needed to prevent the beams from breaking?
I am an extremely slow builder, and have other projects before this one. Does anyone want to build a (model) cat with raked rotation axes, and report back on how it works?