Scaled Composites Model 412 Encore

It's probable that the fact that all section changes are centered around the CG and with such a bulbous nose*, the 412 is optimized for transonic drag (area rules) with a moderate belly pod or wing pods.
That would also explain the switch from a tandem wing to the more drag optimized classical configuration at the expense of the climb rate (?) and the ability to release its Payload without much change in trim.

We would then have a subsonic high flyer with a greater cruise speed than its sibling.

*see 747 bulge
 
IIRC, the tandem wing with replaceable tips was in part meant to accommodate different payloads with different CG locations. I don't know in practice how often such problematic payloads were ever carried on Proteus; Scaled may have just deleted this capability to simplify the design. Maybe they only have one payload in mind, which they can design around, and thus don't need the capability.
 
What an awful design - with the engines right over the wings, its going to have really bad aero interference and high drag. How do I know this? I was the one who figured out that the Learjet 30 series had this issue and then figured out how to fix it. We ended up getting a 5% drag reduction by fixing the wave drag issue (while increasing the induced drag) and another 6% by fixing the induced drag with the leading edge strake (that is not part of the LITE version). https://raisbeck.com/wp-content/uploads/2019/02/ZR_LITE_System_Summary.pdf
 
Aeroweanie said:
What an awful design - with the engines right over the wings, its going to have really bad aero interference and high drag. How do I know this? I was the one who figured out that the Learjet 30 series had this issue and then figured out how to fix it. We ended up getting a 5% drag reduction by fixing the wave drag issue (while increasing the induced drag) and another 6% by fixing the induced drag with the leading edge strake (that is not part of the LITE version). https://raisbeck.com/wp-content/uploads/2019/02/ZR_LITE_System_Summary.pdf
Click to expand...
I doubt this is a vehicle that's going to have to deal with wave drag, even at alt. It probably reaches M=.7 at max. I would be more concerned with trim drag with a thrust line that high, not to mention having to change pitch trim quite a bit with changes in thrust.
 
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