Forward-Swept Wings

Originally posted by emile
What is a RSW?

Rearward swept wing.

Originally posted by emile
If there is no Ramp, where does the horseshoe vortecis come from?

Ramp?

A horseshoe vortex system will form at any interface between two surfaces, one perpendicular to the other.

A wing root and fuselage junction for instance.

Originally posted by emile
yes, three shock wave will caused by FSW a/c because tip of FSW will hit the air before its leading edge.

Sorry, I don't understand you.

I also don't know what the Prandtl-Glauert singularity you've shown is supposed to indicate.

Originally posted by kilcoo316

Originally posted by emile
If there is no Ramp, where does the horseshoe vortecis come from?

Ramp?

A horseshoe vortex system will form at any interface between two surfaces, one perpendicular to the other.

A wing root and fuselage junction for instance.

According to your explain, this vortex only bring drag to the aircraft, will not flow boundary layer from aeroframe

Originally posted by kilcoo316

Originally posted by emile
yes, three shock wave will caused by FSW a/c because tip of FSW will hit the air before its leading edge.

Sorry, I don't understand you.
I also don't know what the Prandtl-Glauert singularity you've shown is supposed to indicate.

Two of shock wave caused by tip of FSW won't occur on RSW a/c.

Originally posted by emile
According to your explain, this vortex only bring drag to the aircraft, will not flow boundary layer from aeroframe

The vortex exists for all aircraft, forward, rearward or unswept aircraft.

It will destroy the boundary layer at the root - I don't know where your going with the idea that the spanwise boundary layer on a FSW causes extra drag.

Originally posted by emile
Two of shock wave caused by tip of FSW won't occur on RSW a/c.

You mean the Mach cone...

Thats why the Su-47 had a maximum top speed of Mach 1.6...

Apparently later structural modifications have allowed the wingtips to pass through the Mach cone - raising top speed to Mach 2.3*- but that will cause drag rises.

Most hard maneuvering tends to happen at subsonic or low supersonic Mach numbers anyway.


*unconfirmed

[edit on 2/9/08 by kilcoo316]

Although this thread is 15 years old, I should mention that Soviet aeronautical engineer Pavel Tsybin designed and built an experimental forward swept wing aircraft in the late 1940s, the LL-3.

Link:
www.secretprojects.co.uk...