lightsaber wrote:cpd wrote:lightsaber wrote:I'm going to disagree. In the industry, we look for step changes in efficiency. That would be the Blended Wing Body (BwB). It has huge structural efficiency advantages and some aerodynamic advantages. I participated in studies that I believe have cleared the evacuation issues. The BwB efficiency grows with scale more than a cigar with wings.
The VLA requires a significant efficiency advantage due to the risk of not filling seats (likely to be realized).
Eventually we will have another VLA. (Never say never) Certainly not in the near term.
Basically, we already know the NMA is delayed. But development won't stop. Only half of new technology can be retrofitted to an existing design. So eventually we will develop new widebodies. But not in the near term.
A blended wing body aircraft has about as much chance of occurring in the next 20 years as the Handley Page skewed wing SST did of becoming reality.
With only two major aircraft makers, they can just put on the brakes for development and do as little as possible. Minor improvements and changes, little more. Nothing risky.
That will be safest. I suspect an SST might be a possibility down the track with variable cycle engines, but it’s surely a long way off and it probably won’t be in the remainder of my lifetime.
This pandemic still isn’t defeated yet either.
SST is so costly, it will only be for limited passenger payloads. We'll have to see how those go in this downturn.
I don't expect a BwB soon, but the basic efficiency is there. Everyone is trying to bring that efficiency. As you note, there are only two vendors who will, like all near monopolies, restrain development. There is always development of those thinking of re-entering the civil market. Businesses are always looking for opportunities.
But with the Boeing BwB x-48, Northrop UCAS, B-21 Raider, and Airbus MAVERIC (I know, small), research continues.
The reality is supersonic transport requires 1st class and higher pricing to move people that quickly.
If you want to cut the cost of air travel, the BwB is a fairly mature technology. The issue, is the efficiency is a *huge* function of scale. The gains really only start for a 250 seater. As environmental concerns grow, there will be a need for a step function reduction in fuel burn. The BwB is one of the few step functions waiting to be implemented now that GTFs are flying, variable cycle in engines has started (just started), and the first bit of CMCs will on the 779.
I worked a little consulting on the Sonic Cruiser very early in my carrier. I was appalled at the sharp increase in fuel burn. For Supersonic flight, that is far worse.
But for the next few years, this is idle discussion.
At the risk of going to technical discussion, was the Sonic Cruiser going fast enough to take advantage of the benefits of high speed flight? I think not, it was just below Mach 1.0 wasn’t it, and with more conventional engines? So no variable inlets, etc. it just seemed like a poor idea. The actual proper SST aircraft gain benefits from going M2.0 versus going at below subsonic speed.