Artifical Gravity & Inertia Dampers

[Carlobrand]

it doesn't matter if the profile is asymmetrical, its the airflow that matters.
Consider the many uses of symmetric airfoil, such as the NACA 00xx or NACA 00xxx series. One famous plane that used them was the Boeing B-17 where both the root and the tip were symmetric. Also many helicopter rotor blade profiles are symmetric. the Convair F-102 and F-106 are examples of interceptors with symmetric airfoils.

All the 'curved' asymmetric surfaces of an airfoil indicate is a non-zero camber. This affects the airfoils angle of zero lift, which works in conjunction with the wings angle of incidence to give the angle of attack in level flight.

The tradition curved asymmetric profiles are generally crap in supersonic flight, hence the interest in wedge and diamond ( double wedge ) profiles. These allow a more favorable location of shock waves and lowered wave drag at speed.

Controls, such as ailerons, and flaps allow control by altering the camber line of the airfoil changing its lift characteristics. Fowler flaps also increase effective wing area.

Some of this is Greek.

Oop, hit the post button by mistake. Okay, for those of us without a degree in Aeronautics, like me: NACA xxxx is a convention for describing how a wing is shaped. The first X is camber - the degree to which the wing is asymmetric.

http://en.wikipedia.org/wiki/Camber_(aerodynamics)

The second X describes where on the wing the maximum camber occurs as a function of distance from the leading edge. Ergo a 00xx is a wing with no camber - top and bottom curve to exactly the same degree from front to back.

Positive asymmetry (top bigger than the bottom) provides lift, but there are apparently situations where a 0 camber wing works well. However, I'm not entirely clear if that 0 camber bit on a B-17 is for the entire wing or just the outer end of the wing, because the linked article mentioned something about using low or no camber at the outer tip of the wing to reduce the chance of a spin. Not being a B-17 engineer, I don't have a way of finding that out.

 

[Carlobrand]

This is a powerpoint from University of Montana on wings and camber and all that stuff. 10 Meg file, so it takes a little while to load up. An interesting bit - most likely known to you engineer types, but those of us who graduated in the soft sciences are often surprised by such bits - is you use flaps to alter camber, so I guess you could have a wing with 0 camber and flaps that would dictate how much if any lift the wing produced.

http://www.google.com/url?sa=t&rct=...6IHYCw&usg=AFQjCNHtFKOYWiXRSeg_y6RgMjqByrr_1Q

 

[Fritz_Brown]

These allow a more favorable location of shock waves and lowered wave drag at speed.

Which brings us back to the reason we mentioned wing shapes and such, at all: turbulence at atmospheric entry and slowing to a landing speed.

The shape (wing or not) will provide some portion of the reason for the "turbs" felt. The shock wave formed by a high-speed entry into atmosphere can case all sorts of issues to the craft. With a wedge you can control the shock wave so that it stays away from the body of the craft, making the ride a bit smoother. With a cigar shape the wave can be disrupted by the curvature of the nose.

As Aramis mentioned: with enough thrust I can make almost anything fly, maybe even supersonic. It's just that the ride won't be worth the effort. With grav drives, I could certainly land a non-streamlined starship in an atmosphere. The issue wouldn't be landing it, it would be whether everything inside were still in one piece or not.

 

[Ishmael]

Positive asymmetry (top bigger than the bottom) provides lift, but there are apparently situations where a 0 camber wing works well. However, I'm not entirely clear if that 0 camber bit on a B-17 is for the entire wing or just the outer end of the wing, because the linked article mentioned something about using low or no camber at the outer tip of the wing to reduce the chance of a spin. Not being a B-17 engineer, I don't have a way of finding that out.

I got the info for plane's airfoil profiles here;
http://www.public.iastate.edu/~akmitra/aero361/design_web/airfoil_usage.htm

 

[PFVA63]

it doesn't matter if the profile is asymmetrical, its the airflow that matters.
Consider the many uses of symmetric airfoil, such as the NACA 00xx or NACA 00xxx series. One famous plane that used them was the Boeing B-17 where both the root and the tip were symmetric. Also many helicopter rotor blade profiles are symmetric. the Convair F-102 and F-106 are examples of interceptors with symmetric airfoils.

All the 'curved' asymmetric surfaces of an airfoil indicate is a non-zero camber. This affects the airfoils angle of zero lift, which works in conjunction with the wings angle of incidence to give the angle of attack in level flight.

The tradition curved asymmetric profiles are generally crap in supersonic flight, hence the interest in wedge and diamond ( double wedge ) profiles. These allow a more favorable location of shock waves and lowered wave drag at speed.

Controls, such as ailerons, and flaps allow control by altering the camber line of the airfoil changing its lift characteristics. Fowler flaps also increase effective wing area.

Hi,

Thanks for the additional info. Another example of symmetrical shapes generating lift at an incidence angle to the flow would be spade rudders (such as on some ships). In ideal normal symmetrical flow, a spade rudder would generate no real side force. However, if the spade rudder is rotated about its rudder post, so that it is now at an angle to the flow, it will generate lift, as shown by the curves at the sites below for the symmetrical NACA 0015 type airfoil (which is a typical airfoil shape for spade type rudders).

http://airfoiltools.com/airfoil/details?airfoil=naca0015-il

PS. Here also is a site discussing some issues about how lift is generated http://www.grc.nasa.gov/WWW/k-12/airplane/wrong1.html

 

[PFVA63]

Hi,

Although this are not flattened pyramids, here is a paper done by NACA providing lift and drag info for a series of flattened (or elliptical cross section) cones, both with and without wings. The curves in this report, similar to the one shown in the post above, relates both lift and drag for these shapes in the form of non-dimensionalized lift and drag coefficients.

From these curves you can see that as the "angle of attack" between the longitudinal axis of the object and the direction of the flow increases lift will increase up to a certain point (until the flow begins to stall out) for these symmetrical objects.

http://www.google.com/url?sa=t&rct=...bgQqelDf8Q6f9uKY-D4dTcw&bvm=bv.49405654,d.aWM