Recent content by DocRocket

Re: Teardrop Camper -- Structural Thoughts The curved upper surface is going to produce some lift, not much in comparison to the drag, but the lighter the construction, the more it will likely matter. The Lift force will act, much like on a wing, at about 25% back from the front most likely...

Re: Teardrop Camper -- Structural Thoughts In all seriousness, you may find yourself doing some layup on the curved parts. I suspect that commercially available flat pieces of thick foam-core board are not going to be friendly to bend to produce your teardrop shape. The 1/4" stuff for your...

Re: Teardrop Camper -- Structural Thoughts Unless you are sold on Aluminum honeycomb panels, you could also look at these: https://dragonplate.com/ecart/categories.asp?cID=207 They have lots of carbon fiber/foam composite honeycomb panels, different ratings, etc... Prices are not cheap by any...

Many bullets and fighter aircraft have pointy noses because they are supersonic. The sharp point is lower drag at HIGH speeds (think 600 mph and up). Take a look at airliners. There is NOTHING about an airliner that is not about improving the lift/drag ratio, unless it is mandatory to carry...

Looks good, and to quote Robert Heinlein: "Don't worry about the theory if the hardware works."

Basically, I think you will want to get your pivot point onto the chord line (or close to it) at the 1/4 chord point. That should be the point at which the aerodynamic forces on the wing are acting, and about which the aerodynamic moment is fixed. In your case, that might actually be above the...

Very cool video, hope the motors can handle the load at speed. Two thumbs up!

Lift force, Drag force, and aerodynamic moment all scale with the square of the speed. The power required to overcome the drag scales with the cube of the speed. This will all hold as long as you are relatively low speed (under about 400-500 mph), for the land speed guys, compressibility...

The problem with using those from below (and I have used them) is that I still have to: a) move a bunch of rock wool insulation out of the way, b) move a bunch of fiberglass batts out of the way, (these are both hard to accomplish through a 4" hole) and most importantly: c) figure out where I...

a) Yes, you can divide the total forces by 2 since there are two motors (and they are arranged symmetrically, etc) b) I like the thought on putting the motors where they use 180 degrees of travel and end up with loads just pushing on the motor shaft--should minimize the torque on the gears...

One thing to keep in mind when you put the pivot at the 1/4 chord point, is that there will be a moment/torque from the airfoil itself. It will likely be about 5% or so of the lift*chord, but in this setup the motor is the only thing countering it. It will tend to bring the trailing edge down...

I completely agree, it would have definitely been far easier for me if they had done it right before :) It looks like I will be spending some "quality" time in the attic putting in junction boxes for the other fans :(

So, if your airflow is about 10 degrees below horizontal over the back window, you should be able (based on the airfoil plots above) to run the wing at about 24 degrees for max lift/downforce. I would stay with the 20 degrees. You also don't (I think) want to push too close to the max CL...

If you can find affordable, small pressure sensors, that are easily integrated to, for example a laptop computer, and will fit inside or on the wing without disturbing the flowfield, you could place a whole bunch of them on the upper and lower surface of the wing and generate a pressure...

It's hard to tell just looking at things, because the AOA is measured from the wind hitting the "wing"--which is not parallel to the ground, because it is disturbed by the car. It is also not likely to be following the slope of the back window of the 911, it is expanding at some angle off the...