Bump-type foil bearings have demonstrated excellent performance in service experiences in recent 30 years. Due to their special structures. the performance prediction models must couple the air pressure with the elastic deflection of the compliant foil structure. The solution of air pressure has been well settled in the hydrodynamic lubrication theory. https://www.roneverhart.com/Apple-Watch-Series-6-GPS-Cellular-40mm-Silver-Aluminum-w-White-Sport-Band/