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Old 03-23-2018, 05:05 PM   #71 (permalink)
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I can't remember where I found the #190, but it may have been a stationery store. It also comes in big rolls under a different number. You might also check out the material now used for full-body signage - "vinyl wrap."

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Old 03-24-2018, 04:31 PM   #72 (permalink)
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I have the weatherstripping mounts installed on the lid piece to somewhat seal the airgaps and am about to go for another ride. I plan to cut some rubber into shapes at some point to make waterproof seals.

This is the first velomobile I have ever ridden and I love riding it. I can only imagine what a Milan SL or Quest or other decently-performing well-made commercial velomobile would be like... The speed improvement is very obvious even without a speedometer installed just going by the higher gear I can cruise in with the same cadence on a given amount of effort before the mid-section piece was first tried versus just having the open body, and also from the open body versus the naked trike.

I took a 10 mile ride with the midsection piece on two days ago, but the air gaps were unsealed and it was held in by nothing but pressure and friction. Now it has latches and the gaps are sealed, and I bet it will make a big difference in drag. I'm about to go on a 30 mile ride and get a feel for it.

This design iteration will be replaced by something with significantly less drag in the coming months.

The CarCycle is an interesting design to study. I like its front end. I have something envisioned in my head but undrawn that looks like a sort of mix of elements between a Panhard CD Peugeot 66C streamliner, LeMans velomobile, Lotus 119B gravity racer, and an Infiniti Prototype 9 designed in a way to minimize aero drag for the given chosen shape style and practical constraints. I might be able to do a prototype shape in coroplast. I think such a shape on my KMX done right has potential to get a CdA in the 0.09 m^2 range or less. I would need to model it and test it, but we'd be talking about a frontal area around 0.45 m*2 necessitating rack and pinion steering. This would make it competitive to a Quest, Strada, or Mango velomobile if this were to be achieved, and I know it is possible for an open-wheeled vehicle to get a Cd in the 0.2 range(Rumpler had a 0.28). Done right, I think it would be very aestheticly pleasing and not expensive to produce or replicate.

I would be very pleasantly surprised if I later found my current existing 4-sided cross section shape as it is today to get anything below a 0.2 m^2 CdA, but I really have no idea what it is at all at the moment.

Last edited by The Toecutter; 03-24-2018 at 04:43 PM..
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Old 03-24-2018, 07:25 PM   #73 (permalink)
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The Car-Cycle has a big air intake in front, but closing it off raises the speed 10%. The next time, I will build a variable opening that provides an efficient diffuser at all settings.
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Old 03-25-2018, 12:30 PM   #74 (permalink)
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I'm curious to see what that new intake would look like. On my next iteration I also decided I would like to be able to open and close the front of the intake from the cockpit, but didn't have in mind making it variable.
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Old 03-25-2018, 02:24 PM   #75 (permalink)
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http://ecomodder.com/blog/aerocaps-for-pick-up-trucks/

I can't find a head-on shot of aerohead's T-100 but it has a perfectly round opening. A cone inside that moves for-and-aft would give an annular orening. And a place to put you mass airflow sensor/pitot tube.
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Old 04-21-2018, 10:04 AM   #76 (permalink)
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The trike is back home in one piece and I am soon going to embark on re-designing and re-building the body for less drag. Before I left Texas, I installed a speedometer and a DNP Epoch freewheel with an 11T sprocket on its 7th gear. As it is today, I can reach 35 mph on flat ground(and not maintain it for any appreciable length of time, only reach it), and cruise at about 19-20 mph with low effort for hours on end.

My goal is to make the body efficient enough to cruise at 25 mph and top out at 40+ mph.

Once I have the efficiency worked out, THEN it will get the overpowered electric drive system for committing random acts of jackassery. I want 0-30 mph in 2 seconds, and that's not happening on human power alone.
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Old 04-26-2018, 08:35 AM   #77 (permalink)
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You'll need a windshield and top to hit 40 on the flat, as most of the drag is in the opening. It makes a big difference. I could hit 40 on the bike trail in the 2009 Carp (#50):



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Originally Posted by The Toecutter View Post
The trike is back home in one piece and I am soon going to embark on re-designing and re-building the body for less drag. Before I left Texas, I installed a speedometer and a DNP Epoch freewheel with an 11T sprocket on its 7th gear. As it is today, I can reach 35 mph on flat ground(and not maintain it for any appreciable length of time, only reach it), and cruise at about 19-20 mph with low effort for hours on end.

My goal is to make the body efficient enough to cruise at 25 mph and top out at 40+ mph.

Once I have the efficiency worked out, THEN it will get the overpowered electric drive system for committing random acts of jackassery. I want 0-30 mph in 2 seconds, and that's not happening on human power alone.
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Old 04-26-2018, 08:56 AM   #78 (permalink)
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A cockpit area can potentially have an attached vortex instead of a solid surface at very low drag penalty. Where a surface is not needed to deflect air, it can be replaced with a smooth, ovoid hole with a radius to the surface at the trailing edge.
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Old 04-26-2018, 12:34 PM   #79 (permalink)
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Kayak skirt?
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Old 04-26-2018, 01:37 PM   #80 (permalink)
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Just my experience is all, not mumbo jumbo.

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A cockpit area can potentially have an attached vortex instead of a solid surface at very low drag penalty. Where a surface is not needed to deflect air, it can be replaced with a smooth, ovoid hole with a radius to the surface at the trailing edge.

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