Hi everyone I'm new. I had an odd thought when thinking about centrifugal compressors. Take a normal straight veined compressor. Normally it just sucks the air straight in and has to accelerate it effectively from zero to however fast it ends up going. But what of you modified the inlet a bit. Instead of being just a hole you configured it so it spun the air as it got sucked in. In a similar manner to what a cyclone separator inlet does. If you make it spin in the same direction as the impeller, then wouldn't it mean that instead of accelerating the air from zero, it would just have to add to its already rotating velocity and so require less power to achieve the final velocity? Well I have thoroughly confused myself trying to work this out. So I thought if anybody could someone here can. Thanks in advance for your replies.