sweep angle

[flyguy80]

hi there just a quick question, if you increase the angle of sweep on a jet how does it affect the stall speed, just need a proper way to phrase it thanks

[BOAC]

There are too many unknowns/variables in your question to give any answers, but feel free to join in at http://www.pprune.org/questions/392029-vertical-stablizer.html :)

[bfisk]

As far as I can remember, the CL/AoA curve for more vs less sweep, gives you same CLmax but at a higher AoA for the more swept wing, all other parameters not considered. So this would lead to the same stall speed for the same wing area and aircraft mass, but it would occur at a higher AoA and consequently higher body angle given same flight conditions.

[XPMorten]

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19640014908_1964014908.pdf

XPM

[Pugilistic Animus]

in reality that is a :\:\:\ question--Like BOAC says

for a detailed answer you could also try Abbott and Vandoenhoff 'theory of wing sections' they discuss sweep in detail in the section of 'the effects of compresibity at high subsonic speed' of course with the assumptions of infinite side slip and an infinitely long span:8

PA

[Brian Abraham]

XPMorten, many thanks for that, I searched the site but missed that. Some bed time reading, looks most interesting and informative.

[Pugilistic Animus]

other aspects to consider wrt to swept wing aeroplanes are dihedral effect in terms of both stability and stall characterisics: the plan form effect of aerofoil section [that make up the total wing--where some sections may be of a differing airfoil design] the low lift slope curves of those sections, the higher angles of attack required to produce lift at low speeds as well higher angles of stall, the effect of other airplane--- stuctures--- fuselage, canard, tailplane position, only by assuming an swept elliptical planform are elliptical distrubution, dihedral efect washout and twist---this is why even with some basic equations for the characteristics of these sections bboth wind tunnel testing and FLIGHT TESTING must be done,...because even the geometry of the tunnel affects the actual characteriscs experience in flight; and lastly it depends on whether you mean wing section stall or 'airplane' stall

a good simple reference on high spped flight is found in H.H hurt's 'aerodynamics for naval aviators as well careful reading of some of Davies text reveals some more,...:)

PA