Numerical Predictions of Flow and Heat Transfer for Rotating Internal Cooling Channels with Rib Turbulators

To investigate flow and heat transfer in a rotating internal channel of the moving blade,experiments and numerical simulations for a similarly amplified channel model with 90°ribs are conducted. The inlet Reynolds number,flow rate distribution ratio and geometric dimensionless ratio are taken as 17 000,1∶2∶1and 46.4respectively,the rotating number is considered as 0and 0.09.The heat transfer coefficient distribution and static pressure coefficient are examined by experiments.The effects of vortex on flow and heat transfer in rotating internal cooling passage are achieved with 3-D numerical simulation.The results show that vortex shift in rotating channel changes velocity field,and the static pressure coefficient increases along radial outflow and decreases along radial inflow due to centrifugal force.The laterally averaged Nu distributes in multiple-peak form as the result of secondary flow induced by rib turbulators.The Nu distribution down stream of turning area gets asymmetric due to turning eddy.The fluid shift tends toward the wall that the Coriolis force points to.Consequently,the Nu on the radial outflow pressure surface and radial inflow suction surface increases.