Hello, I'm currently trying to develop a simple model for a tuning fork gyro. In calculating the damping as first approximation I used the couette flow damping. Is there any analytical formula which expresses the air viscosity as function of the air pressure. I know that air viscosity is about 1,7/1,8*10-5 Ns/m^2 at ambient pressure. And at different values like vacuum or something in the middle? Thanks in advance. Best Regards, marco chrappan