3 ms·
The air pressure 10 km above sea level is about 25 % of the air pressure at sea level, the Hyperloop paper says the air pressure in the tube will be 0.1 % of th
by danbruc 10y ago
The air pressure 10 km above sea level is about 25 % of the air pressure at sea level, the Hyperloop paper says the air pressure in the tube will be 0.1 % of the air pressure at sea level. So the pressure is way closer to a perfect vacuum than to the air pressure outside of airplanes.
- stouset 10y agoIt's still a linear change. The tube needs to withstand 1 ATM of pressure, which isn't all that much in the grand scheme of things.
- danbruc 10y agoWithstanding one atmosphere is certainly not an unsurmountable challenge but given the dimensions and given that this thing is supposed to be cheap it is also certainly not a negligible issue. You also have to maintain the quality of the vacuum, possibly in presence of expansion joints, and you have to deal with the consequences of a loss of vacuum for whatever reasons.
- jessriedel 10y agoYes, the mechanical forces involved with a 0.75 ATM differential are very similar to a 1 ATM differential. But the same isn't true for leaks and residual gas because the difficulty isn't linear. Pushing a vacuum 0.1 ATM to 0.01 ATM is much harder than from 0.51 ATM to 0.501 ATM.