From: alain245@videotron.ca   
      
   On Apr/22/2023 at 20:59, Snidely wrote :   
   > On Saturday or thereabouts, JF Mezei declared ...   
   >   
   >> Apparently, the OLM is already fairly high off the ground, but the beams   
   >> that support it all around make it difficult to make an above ground   
   >> flame diverter/trench.  I am not all that concerned about a below ground   
   >> flame trench that is filled with water. Wouldn't the exhaust very   
   >> quickly push that water out to sea with said water providing some   
   >> protection to the flame trench floor?   
   >   
   > I'm sure you can provide us with a model that shows the expected   
   > results.  Just a bit finite element code.   
   >   
   > /dps "or ask a civil engineer"   
      
   In a case Mr Mezei didn't understand what Mr Snidely was saying:   
      
   The exhaust from the rocket is a complex super-sonic flow. There will be   
   a bounce back of the shock-wave towards the rocket. The shape and timing   
   of such a bounce back is not a simple thing and can have some   
   counter-intuitive effects. A flame trench is not just a simple thing   
   that you ask a guy with a shovel to dig according to some sketch on a   
   napkin. You need to optimise the shape (that is where the finite element   
   code comes in).   
      
      
   Alain Fournier   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)