Wind tunnels are fun, we used to use them to design the aerodynamics for our torpedoes
we also worked with the water tunnel at Glasgow to investigate cavitation. But the prize winner of facilities was the rotating beam at Teddington (photo attached).
We would dangle our model torpedoes off the end of it and then phone up the electricity board to warn them we were about to run up the 1500HP electric motor
that drove the beam through a series of gears. For some reason a figure of 30 comes to mind
not sure if it was 30m long or rotated at 30 rpm I know that it provided the 100+ knots we were using. You should have seen the wake throwing water up the walls
The instrumentation used to capture all the data for us but just under the level of the water there was a viewing screen where you could see the models whoosh by. And boy did the beam whoosh by, it was more of a low "woom, woom, woom " as it went round.
Those were the days
Jo
