Fred Friday evening a grandson and a friend went to a pile of scrap lumber to set it on fire... One of them poured 4 gals of gasoline into the pile. It was a very still evening with NO WIND! Not even a whisper.. When my grandson struck a match there was a huge explosion... Fire lept 60 feet in the air and lumbar parts flew up with it.. My grandson has 2ed burns over 20% of his body from this he will have a complete recovery we are told..
My point in telling this story is that although there was NOISE and FLAME Sunder would say that it was not an explosion.. In truth it was the same as inside of a cylinder. EXPANSION of the burning fuel is what caused the seeming explosion..
I guess a true explosion would be when a container has so much internal pressure that it is torn to pieces by the pressure ie BOMBS or firecrackers..
But like you I do not know another word that would suffice for what it is that happens in there.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />