Mielenkiintoista juttua Eurofighterin suunnittelusta ja aerodynamiikasta, itsekin olen miettinyt joskus tätä:
https://hushkit.net/2017/12/29/ask-the-insider-eurofighter-typhoon/
Why did the cranked delta wing of early concepts change to the conventional delta?
“I was not involved in EF configuration design decisions. Because I was not involved, I can speculate a bit.
The essentials for EF were keeping the weight low (maximising thrust to weight) and minimising transonic and supersonic drag to achieve outstanding energy manoeuvrability. This is the ability to engage, manoeuvre, shoot, disengage, accelerate and re-engage at high energy, and the aircraft is quite exceptional in this regard. Other key factors are high instantaneous turn rate delivered through a highly unstable configuration and a smart fcs which delivers pilot intent while managing airframe loads; and good sustained turn rate, delivered through low weight and wing loading, and an aerodynamically optimised close coupled canard configuration.
Why might the cranked delta of EAP not have been used? Some possibilities are:
– A straight leading edge should lead to a simpler and lighter wing structure (Weight, Cost/Complexity);
– Maintaining a higher sweep on the outboard leading edge rather than having a reduced-sweep cranked planform should reduce wave drag, improving both acceleration and supersonic performance (Drag);
– Aerodynamic interaction with the canard may have been more favourable, either through having more linear characteristics at incidence, and/or allowing the fcs to manage a greater degree of instability (Drag, fcs design);
It is possible either more favourable or more linear aerodynamic cross coupling characteristics are obtained. For highly manoeuvrable unstable designs the cross terms such as rolling moment and yawing moment due to sideslip can have a big impact on handling qualities (fcs design).
What might have been traded away?
Perhaps an impact on low-speed, high alpha qualities. The value of extreme high alpha flight to a modern fighter is questionable, and EF performance already benefits from low wing loading, loads management from the FCS, and high thrust to weight.”