A theoretical and experimental study has been conducted to Investigate the turbulent separated flows behind a rotating cone. Measurements of the pressure, mean velocity, and turbulence intensity were made with a micromanometer and a hot-wire anemometer. As a theoretical part of the study, a general finite-difference calculation procedure was developed for heat transfer prediction of the axisymmetric turbulent separated flows with a nonzero tangential velocity component. A special effort was made to deal with irregular boundaries. The calculations performed with the present numerical method and the k-ε turbulence model are compared extensively with experimental data obtained for various apex angles, free-stream velocities, and angular velocities.