Compound delta on Mirage IIIV

[R_K_M]

The Mirage IIIV has a small but noticeable compound delta. Sadly sources I find on the internet never mention this and no explanation of why this was done (better high AoA performance? weight distribution or area rule consideration with the new fuselage?) is given. A larger LERX/compound delta also shows up again on the Mirage IIING (here most likely for more lift/better high AoA performance) but interestingly not on the Mirage 2000.

Does anyone has more insight or a good source/book that talks about Dassaults early ventures into compound deltas/LERX?

 

[Deltafan]

The Mirage IIIV has a small but noticeable compound delta. Sadly sources I find on the internet never mention this and no explanation of why this was done (better high AoA performance? weight distribution or area rule consideration with the new fuselage?) is given. A larger LERX/compound delta also shows up again on the Mirage IIING (here most likely for more lift/better high AoA performance) but interestingly not on the Mirage 2000.

Does anyone has more insight or a good source/book that talks about Dassaults early ventures into compound deltas/LERX?

At the moment, I only have these features on the MD-600 project

https://www.secretprojects.co.uk/threads/avions-marcel-dassault-md-designations.1491/post-273647

-10% more wing area (34,85 m² for the Mirage III => around 38,34 m² for MD 600)
-Wing with LERX (like the Mirage III V) for 5% more lift at high incidence

 

[Deltafan]

The Mirage IIIV has a small but noticeable compound delta. Sadly sources I find on the internet never mention this and no explanation of why this was done (better high AoA performance? weight distribution or area rule consideration with the new fuselage?) is given. A larger LERX/compound delta also shows up again on the Mirage IIING (here most likely for more lift/better high AoA performance) but interestingly not on the Mirage 2000.

Does anyone has more insight or a good source/book that talks about Dassaults early ventures into compound deltas/LERX?

Hi, second answer:

I had some time to look in the book Mirage III, volume 3, Chenel-Moreau-Liébert, DTU editor, 2008.

There is nothing concrete for the Mirage IIIV. Apparently the LREXs were mostly meant to get a bit more lift while making as little change as possible from an original Mirage III wing. Pilot Jean-Marie Saget writes: "Most of the flights did not consist in studying the qualities of conventional flight, but what we saw was perfectly satisfactory."

For the Mirage III NG, it is more precise:
Tests in the wind tunnel have shown that at high angles of attack (25°), the presence of canards generates lateral instability with a risk of a spin start, but the presence of LREXs should reduce this risk. On the other hand, in almost the whole area, the gain in maneuvering room is of the order of 2G, the expected advantages during take-off and landing remaining marginal.