11 ms·
1,000km/h is within what is conventionally considered transonic (965-1235km/h). I wonder how practical these speeds are without a containing tunnel, particularl
by gnode 7y ago
1,000km/h is within what is conventionally considered transonic (965-1235km/h). I wonder how practical these speeds are without a containing tunnel, particularly on the ground where there is potential for damage to buildings, structures, wildlife, etc. from sonic booms. Additionally, as I understand it, reflecting objects and terrain at ground level increase the potential for generation of sonic booms at transonic speeds. Indeed, sonic booms are generated by trains today when going through tunnels where the air ahead of the train is constrained and compressed.
- hojijoji 7y agoAt these speeds, the train would need to drive in a low pressure tunnel.
- NamTaf 7y agoIt’s worth noting that this isn’t necessarily that big of an issue for China. A lot of their HSR is grade-separated and not infrequently up on viaducts. It’s not a particularly big step in my mind to enclosing that.
- gnode 7y agoI'm not sure it's strictly necessary to have the tunnel be low pressure. It's nice for the sake of less resistance, but the speed of sound is actually lower at lower pressures, and so would more readily produce a sonic boom.