Aviation might be a "small" contributor to the problem (transportation represent about 15% of global greenhouse gases emissions, and aviation is just a part of that), but we are at a point where every single gram of CO2 counts. That fact that are bigger contributors is not an excuse to not...Jump to post
I always thought of the EJ200, Snecma M88 and F119/YF120 as good basis for engines to power hypothetical new supersonic transport aircraft. The first two for business jets and the latter for airliners.
All of them are relatively modern designs and conceived with supercruise in mind from the get go.
In a perfect system, you could accelerate a bit above the exhaust speed of an air breathing jet engine, do to the added mass of fuel to the total flow. ;) In practice, yeah, you need to accelerate the exhaust above the speed you want for the plane. And that's not going to happen with high bypass tur...Jump to post
and we were discussing why you couldn't hear the sonic boom for the launch (but you could hear it on reentry) and he said something to effect of the fact that after a certain altitude, you can't effectively hear a sonic boom. I'm no expert or anything, but might be that a big factor in not hearing ...Jump to post
I don't think a 96% load factor is something worth striving for. Calculations I've seen elsewhere suggests the sweet spot is around 85%. If your load factors are near 100%, you should increase the prices of tickets until it drops to around 85%. That's where you make the most money. Not sure that wo...Jump to post
Can't be absolute. In order to produce thrust, bypass flow must be accelerated above the vehicle speed. I would guess the delta starts big at take off and then gradually shrinks as the plane picks up speed. But never reaches zero. Core flow could produce thrust at absolute speeds equal or even a bit...Jump to post
GalaxyFlyer wrote:The only other geared fan engine, the TFE 731
Add a Vulcan second stage one day and there is nowhere in our Solar system it can't go. Vulcan is the Ariane engine, did you mean Raptor engine instead? He might be referring to the future Vulcan rocket, by ULA. I highly doubt that ULA would be willing to supply ACES upper stages to SpaceX, though....Jump to post
Watching the live stream of the post-launch news conference, Musk has confirmed that the core did indeed not land safely. As far as I could hear (the audio quality was a bit meh to start out with), it ran out of propellant and hit the water at 300 MPH I understood it run out not of propellant but o...Jump to post
I would add that a bit of an hard impact upon "landing" was far better than a possible much harder impact upon falling down after stalling, had not the flight envelope protection been in full effect.Jump to post
Perhaps it's a safety thing? So that passengers will be readily aware of any crew indications in an emergency situation?
Some airlines might think it makes a difference, and others not so much.
Just guessing, here...
*Or did I calculate something wrong? Entirely possible. I know engine efficiency is not in the calculations but it should be good enough to not cause problems. You did. Hint: 18650 cell can provide 80W of power for how many miliseconds? Many. I would appreciate if you could spend at least few secon...Jump to post