Centrifuging hot air in a pipe, does it take more power than liquid
I am currently working on a prototype Gas telescope lens , One of the ways it works is by heating the pipe then spinning the pipe, my question is how easily will hot air be spun outwards inside the pipe, does it need to be spun more or less compared with the force needed to spin water outwards
When pipe is heated first ,then spun ,the hot air is spun outwards inside the pipe and then pumped out of pipe along walls causing cold air to be drawn in centre creating a lens, a descent section of pipe on each end is needed to separate ends of pipe from heat so cold air can be drawn in ?