When I was a younger man, I had an aircraft washing service. At our local airport the Goodyear blimp would come by and dock, have repairs done, and occasionally have the ground crew do helium dives inside. It is rather interesting to watch them do this as they go into the inside of the blimp and suit up as if they were going on a underwater diving expedition. Obviously you can’t breathe helium for very long without oxygen. It was fun to watch, and eventually I was able to get the contract to clean the gondola or the pod for the people and passengers under the blimp.
My company got the contract to do the washing, waxing, and cleaning of all the Windows. We occasionally even vacuumed the inside. No, there wasn’t much to it, and it was an easy job, but it was fun for a young man with an aircraft washing service if nothing else than for bragging rights. One time the blimp started up, and one of the engines was making a terrible amount of smoke. But, the blimp started forward, and then a big wind gust came and it was floating in reverse with the engines going as fast as possible. All that smoke covered the gondola and the whole thing was dirty again.
Perhaps you have taken an off-road vehicle and gone back through all the dust you created, or stopped after creating the dust only to have it engulf your vehicle. Interestingly enough, this type of action is something that is constant at the beach, especially in the swash zone. It’s that area where there is no surf and the water is only a few inches high, but races up the slope only to recede, and be pushed by the next set of waves which have already broken.
Now then, consider the mathematical modeling behind the swash zone, and what is happening on the boundary layer and surface of a dirigible during reverse thrust phases, or when it is pushed backwards by the relative wind even as it has added forward propulsion. You can understand how the aerodynamics of the blimp itself have been totally replaced by a new aerodynamic phenomena which is very similar to the fluid dynamic scenario of the swash zone.
Interestingly enough, the mathematical modeling and computational equations used for swash zone are quite simple, easy to calculate, and completely similar to what is going on with the scenario I described above with the blimp. Indeed I hope you will please consider all this and think on it.