by78
General
Very recent (November 25, 2019) publication of "Research on impact of canard to RCS" by 611. The article seems to have been submitted in 2017.
Summary:
It is interesting to note 2.2 where Canard configuration is inherently better than conventional on the side.
- Comparison of conventional and canard configurations of otherwise the same fuselage, based on F-35.
- Before improvement on canard configuration, compared to conventional layout, Canard has
- Slightly worse RCS return in frontal area from 0 to 30 degrees because:
- Canard aft edge reflection is exposed while conventional horizontal stabilizer is blocked by main wing.
- Sharp end of aft edge of canard.
- The gap between canard and fuselage is another strong contributor, but mostly to high frequency (C band).
- Much less RCS return from the side, from 30 to 90 degrees, because conventional horizontal and vertical stabilizer forms a strong reflector while canard does not.
- Improvement
- Use radar absorbent structure (not paint) on all edges, the light grayish green area. It is much better than paint in terms of frequency band and size.
- Smooth curvature and seal of the inner edge of canard.
- Cut the corner of canard aft edge.
- After improvement, the conclusion is that canard configuration with proper measures is equal to conventional configuration in RCS.
- As to the "canard moving increase RCS":
- the test shows that within +- 5 degree movement (in cruising), there is both increase and also decrease (-5 degree). Overall neglect-able.
- When the canard must be turned more than 5 degrees, the aircraft is in a situation where the whole RCS has drastically increased (close dog fight or violent maneuver) making canard's contribution neglect-able or the whole stealth thing non-existent.
View attachment 55945
Here's the paper in full for those who are interested. It's beyond my limited Chinese to translate this. Anyone wants to take a crack at it? It might just resolve the ongoing endless back-and-forth. Or am I too optimistic?