I agree that the primary hurdle in implementing different types of airframes is public reception and the accompanying financial risks, but other points–specifically that building such structures requires the use of nontraditional materials–is not correct. You could build a flying wing or blended wing body using standard aircraft materials of steel and aluminum, and in fact this would be easier to fabricate and assemble than composites. Composite materials are used on military combat aircraft not primarily because of their light weight or high stiffness but because they offer a low radar cross section (RCS).
The French/British Concorde SST failed not because of technical problems but because it wasn’t financially viable. The Soviet SST did encounter a number of technical limitations, but doubtless if they had the money and incentive to develop it further they could have overcome these. The SSTs were an answer to a question no one was seriously asking.
As for the controls technology required to stabilize non-conventional aeroshapes in flight, you are correct in saying that there is an existing body of knowledge and information regarding the associated phenomena, and the requisite computing power to provide control of active feedback systems; however, this knowledge base resides almost exclusively in the domain of military combat aircraft designers. Even if you could shift this directly over to commerical aircraft development, each aircraft is, to some extent, its own unique problem, particularly in the case of dynamically unstable flight. It’s not as if you can just pull the controllers out of a B-2 Spirit and plug them into a hypothetical Boeing Commerical Flying Wing with a few minor tweaks in software parameters; even adapting an existing control system would require substantial testing and verification, and this is an additional cost (and schedule risk) above and beyond the costs of development, tooling, and promotion of a new traditional design. There are manifest advantages to alternative body designs like a blended wing body, as I’ve outlined above, but there are also large unknowns that may impact the ability to project a cost and timeline. In comparison, a traditional wing and tube design has been done enough that the major operations and costs are (generally) well understood, at least from a design standpoint.
Finally, I have to take issue with your notion that modern controls allow you to fly any old thing any way you want. The laws of physics still apply, and aeroshape that are statically unstable–that is, do not display even nominal stability in level, unimpeded flight–are generally unflyable, regardless of your control system. Real world, non-linear systems are modeled and controlled by “linearizing” them; identifying in regions of interest solutions that can be approximated as linear behavior, i.e. problems that can be broken down into smaller, easily solved chunks that can be all superimposed together to give a “good enough” solution to the overall behavior. It’s certainly possible to develop a system even in theory which defies any attempt to control it by virtue of its essential chaotic, unlinearizable behavior. Even when a system can be linearized, it’s not a simple matter of using some standard software and plugging in a few numbers; each individual regime of behavior has to be modeled per its own special characteristics, and often small perturbations in these numbers result in large changes.
As an example, I’ll point to the V-22 Osprey tilt-rotor aircraft; even though the flight transition from forward to hover occurs at low speed, the complexity and sensitivity of the operation required years of specialized development and analysis by dozens of engineers and scientists and demands a fairly narrow range of control by the pilots. It’s just not as simple as slapping a computer on it and making it go.
Stranger
