Quote:
Originally Posted by freebeard
Detachment is always associated to vortexes, yes no, maybe?
A vortex is just self-sustaining ordered turbulence?
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* Downwash is phenomena associated with attached, upper longitudinal vortices.
* Upper longitudinal vortices are a phenomena associated with transverse viscous shearing forces at the intersection of the top and side flow.
* Viscous shearing forces are associated with the pressure differential between the top and sides of the vehicle.
* Pressure differential is a function of the pressure gradient along top and sides.
* Pressure gradient is dependent upon the aft-body contour, degree of cross-sectional area contraction.
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* Typically, there exists a maximum contour producing an adverse pressure gradient which will just sustain attached flow.( a streamlined contour )
* If this contour is exceeded, the magnitude of the critical, local pressure gradient is also exceeded, triggering flow separation, as per the strictures of boundary layer theory.
* At zero-yaw, a 'streamline' body is incapable of generating separation. One underlying criteria for the 'template.'