Hi Dave,
The noise will be increased to a airflow velocity inbound Mach 1,1 in 6 to the power of the airflow velocity. Must be shocking!!!
I have some material from shukowsky (russia) about the supersonic rotor, but unfortunately is my academic english not good enough to translate it comprehensible
They have it fully metric and with other terms.
I'm 2 weeks out, but i will see...