Then it wouldn't the vertical strakes as addiotnal vortex generators. Would also render Dr. Song's paper as obsolete because the design team went with a different aircraft design. So seeing some nice analysis of the aircraft design and design elements by some Chinese experts who have maybe even access to some quantitative data would be an excellent read.
Canard downwash effect is strongest in close coupled canard configuration, but it’s not nothing if there’s a longer coupling distances, and if it interacts with other vortex generators. In fact in the paper Dr. Song mentions
“Canards on close coupled canard configuration aircraft have relative short lever arms. Employing the LERX canard configuration can increase the canards lever arms while retaining the benefits of positive canard coupling. Considering the overall lift enhancement effect and pitch down control capabilities, we can set the canards maximum relative area to around 15% and the maximum canard deflection to 90 degrees.”
We can see this in the the following picture. Note the vortex trail on the outboard edge of the wing, which originates separately from the vortex trail generated by the LERXes and the dogtooth formed by the deflection of the leading edge flaps.
The design Dr. Song details in the paper *is* the design the team went with. Dr. Song was the chief designer for the J-20. In case you didn’t read the study, this was their proposal.
The design team made a future fighter proposal based on the points raised by this article. The proposal employs lift-body LERX canard configuration. It is unstable in both the lateral and yaw directions. The proposal employs small aspect ratio wings with medium back sweep angle, relatively large dihedral canards, all moving vertical stabilizers far smaller than those on conventional fighter aircraft, and S-shaped belly intakes. According to our assessment, the proposed aircraft will have excellent supersonic drag characteristics, high AOA lift characteristics, high AOA stability and controllability, and excellent stealth characteristics.
Lerxes, small aspect ratio wing with medium back sweep, large *dihedral* canards, small all moving tails all fit the J-20. The only difference was the belly intake.
The canards on the Rafale are for lift generation at a wide range of speed (important for carrier operations) and AOA unlike the Typhoon ones, which are there to generate longitudinal unstability and pitch authority - crucial characteristics for being mainly an air superiorty fighter.
Not exactly. The Typhoon has strakes that generate a small vortex which acts as a vortical core that strengthens the downwash from the more distantly coupled canards, which then lets the canards control the lift coefficient over the wing, which can be seen in the picture below. This allows the Typhoon’s canards to be both vortex control devices and pitch authority devices.
Sorry for continuing this discussion Deino. This is the last I’ll post on it here. I’d recommend moving this discussion to the appropriate thread if you have the time. If you do, also sorry for creating more work for you.
