Spit IIa

[Crumpp]

Crump you are mixing terms

Nobody is mixing terms.

Aggravated in terms of aerodynamics is not a common term.

Sure it is a common term.

Simone Zuccher∗ and Sergio De Ponte†
Politecnico di Milano, 20158 Milano, Italy.
DOI: 10.2514/1.25389

The spin of an airplane occurs for angles of attack beyond stall, where nonlinear aerodynamics dominates and where complex and unpredictable behaviors might induce to question whether or not such a motion is chaotic. To find an answer to this issue, wind-tunnel tests are carried out on a model of a fighter attached by its center of gravity through an universal joint that allows only the three rotations. These degrees of freedom are analyzed according to modern techniques for the study of “supposedly chaotic data.” It is found that, for increasing Reynolds number, successive bifurcations take place with a consequent more complex structure of the attractor, which reveals some features typical of quasi-periodic systems evolving toward chaos. The model is tested also in other configurations (different nose and/or leading-edge extensions, presence or absence of tail planes) so as to verify the dependence of the motion on some details. It is found that unpredictability and strong dependence on the initial conditions characterize
the basic configuration, whereas a blunt nose and leading-edge extensions make the motion extremely regular. Even though the system might be on its route to chaos, a fully developed chaotic behavior is not observed.


Nomenclature
c = wing mean chord, m
f = frequency, Hz
k = reduced frequency, fc=U1
Re = Reynolds number, U1c=
t = time, s
U = wind-tunnel streamwise velocity, m=s
t = time interval, s
= kinematic viscosity, m2=s
= time delay
’, , = degrees of freedom (roll, pitch, and yaw), deg
Subscript
1 = asymptotic (freestream) conditions


I. Introduction
SPIN is an aggravated stall that results in autorotation [1].

http://profs.sci.univr.it/~zuccher/d...DS_JOA2007.pdf

A standard copybook 1G stall and spin entry has you arriving at the Critical AOA in 1G flight with close to full backstick. As the stall develops (ideally a nanofart before) you smoothly apply and hold full rudder (I guess you could say this is "aggravating" the stall ).

Any stall under any acceleration is aggravated. Anytime you have uncoordinated flight, you have lateral acceleration.

http://books.google.com/books?id=nxb...flight&f=false

The primary cause of an inadvertent spin is exceeding the critical AOA while applying excessive or insufficient rudder and, to a lesser extent, aileron. Insufficient or excessive control inputs to correct for Power Factor (PF), or asymmetric propeller loading, could aggravate the precipitation of a spin. At a high AOA the downward moving blade, which is normally on the right side of the propeller arc, has a higher AOA and therefore higher thrust than the upward moving blade on the left. This results in a tendency for the airplane to yaw around the vertical axis to the left. If insufficient or excessive rudder correction is applied to counteract PF, uncoordinated flight may result.

http://faculty.chicagobooth.edu/john...C%2061-67C.pdf