Official Answer
Answer
Centrifugal force acts to expand an external ring, potentially leading to 'liftoff' from the groove. The limiting speed $V$ in RPM is calculated using $V = \sqrt{\frac{4 E I g (D_G - D_I)}{\gamma A R_m^3 (1 + 1/N_{turns})}}$, where $D_G$ is the groove diameter, $D_I$ is the ring inside diameter, $I$ is the moment of inertia, $\gamma$ is the material density, and $R_m$ is the mean radius. For high-speed applications like turbocharger assemblies, selecting a ring with higher wall thickness or using a 'self-locking' tab design is mandatory to increase the effective stiffness against radial expansion.
