Prompted by current news I was idly thinking about how caverns and tunnels get impacted by surface level blast overpressured.
How much of the energy will get transmitted as opposed to reflected will depend on impedance matching. There are two very important transitions (i) open air to air inside cavern and (ii) cavern air to cavern walls.
Regarding (ii) unless the density transition is eased into, (gravel and sand ?) the energy in the air will get reflected right back. Very little will get transmitted into the rock walls.
Same principle applies for (i). As a resident of such a cavern you would want high impedance mismatch. It makes sense to have well matched labyrinths to dissipate the energy much like silencers and mufflers. One would want all the energy be converted into turbulence, safely and quickly.
I wonder if these considerations inform their design. Probably does.
How much of the energy will get transmitted as opposed to reflected will depend on impedance matching. There are two very important transitions (i) open air to air inside cavern and (ii) cavern air to cavern walls.
Regarding (ii) unless the density transition is eased into, (gravel and sand ?) the energy in the air will get reflected right back. Very little will get transmitted into the rock walls.
Same principle applies for (i). As a resident of such a cavern you would want high impedance mismatch. It makes sense to have well matched labyrinths to dissipate the energy much like silencers and mufflers. One would want all the energy be converted into turbulence, safely and quickly.
I wonder if these considerations inform their design. Probably does.