Effects of flow distribution ratio and rotation number on flow and heat transfer of rotating internal cooling channels

Numerical simulation is employed to study a rotation cooling channel model with 90°ribs. The purpose of the study is to reveal the influence mechanism of the rotation number and discharge ratio on internal cooling channel heat transfer characteristics and to understand the heat transfer distribution of internal channel in rotor blades. The model contains 3 passages and 2 turn areas. The inlet Reynolds number and rotating number in passages are 17000 and 0 to 0.09. The outlet mass flow rate discharge ratios in three passages are 27%49%24%, 27%0%73%, and 27%73%0%, respectively. The results show that only the pressure coefficient and Nu distribution in the third channel are affected by the discharge ratio in the static channel, and the pressure coefficient and Nu distribution are obviously changed in the rotation channel, and that the pressure coefficient increases along radial outflow and decreases along radial inflow due to centrifugal force. The lateral average of Nu distributes in a multiple-peak form as the result of secondary flow induced by rib turbulators. The distribution of Nu in the downstream channel of turning area gets asymmetric due to turning eddy.