What sound does a low intensity thermobaric make? By 'low intensity', I mean one with a blast front which never exceeds, let's say, 100 mph.
Hokey smokes!!
You're going to get Stundied for that one. I'm not going to do it, and I don't participate in teh Stundies, I'm just warning you.
Either you're playing dumb to gain some leverage off my sense of charity (not a bad strategy) or you're even more confused than I could have imagined. But I'll try to help. We have to go back to Square One for this.
There is, by definition, no possible explosive of any kind with such a low blast front speed. Remember what we're talking about, here. The "blast front" you are describing is a
pressure wave. In the case of a high explosive, like TNT or RDX, the "blast front" is a shock wave, and is therefore supersonic. The speed depends on a lot of things but will exceed 340 m/s, or 770 MPH to use your choice of units. A low explosive, like black powder, does not generate a shock wave, instead generating a possibly large in amplitude, but not sharp, pressure wave. This wave moves at the speed of sound, 770 MPH.
The sound speed is the minimum speed of the "blast front." There is no explosive, not of any kind, that will go a mere 100 MPH.
To get such a slow speed, you're not talking about explosives any more, nor a "blast front." That kind of speed, being at Mach numbers of < 0.15, is definitely in the regime known as "incompressible flow." Since we're not setting off this strange device in a sealed chamber, the static air pressure remains constant. The only forces are kinetic, i.e. what "pressure" you feel is strictly due to the air's velocity. Your device will simulate the effect of a 100 MPH gust of wind.
Because the force is purely kinetic, we can calculate the actual felt pressure directly -- it only depends on speed in this case. Using the
Bernoulli equation, the felt pressure is equal to
ρ v2 / 2, where
ρ is the density of air, and
v is the speed of the air at infinity.
In your case, the speed is your mandated 100 MPH (about 45 m/s), and air density is about 1.2 kg / m
3. The felt pressure then works out to about 1200 kg m
2 / (s
2 m
3), or 1.2 kPa. In archaic units, this is 0.17 PSI.
That's it. Not even enough to break windows. Abandon this hypothesis now.
The only way you can reconcile such a slow airflow speed with structural damage is if your mystery device is in
mechanical contact with the structure -- rather than transmit a "blast wave," it just pushes on the columns. That, of course, can be done as slow as you wish.
So rather than focus on hyperbaric explosives, you should instead start looking into hypotheses involving, for instance, expanding foam, or (dare I say) collapse of the upper structure.
If you need still further help, as I imagine you do, please start another thread. This is long overdue.