Abstract: Numerical simulation was conducted to study the rotational effects on flow and heat transfer in pin-fin rotating ducts.The pin-fin is low and the chord-wise pin spacing is small.Numerical results show that rotation influences the pressure distribution and chord-wise ejection mass flow rate.In pin-fin rotating duct,the pressure increases gradually in the radial direction due to the effect of centrifugal force.The chord-wise ejection mass flow rate becomes smaller near the entrance and becomes larger near the radial exit.Rotation also influences the wall heat transfer,and enhances the pin-fin endwall heat transfer slightly.The heat transfer on the leading side of the duct is slightly higher than that on the trailing side.