The effect of a hub turning vane on turbulent flow and heat transfer in a four-pass channel at high rotation numbers

Rotating Heat Transfer Measurements on a Multi-Pass Internal Cooling Channel: II — Experimental Tests

“…Inside the 2 nd leg, the behavior is similar but with the difference that the thermal field development is affected by the flow evolution after the bend. Indeed, it is well known that 180° turns without vanes (as in the present case) determine an acceleration of the fluid layer on the external side of the path with flow separation close to inner corner [18,19]. Downstream the turn, the flow will progressively recover from separation and it will develop towards a more uniform flow distribution over the channel span.…”

“…The heat transfer performance inside the second and third legs can be significantly modified by the presence of the upstream turn. Indeed, inside the bend region complicated flow structures such as separation, recirculation, and secondary vortices arise, [18]. Adding rotation and channel orientation increase the complexity of the flow, resulting in different behavior if a tip or hub turn is considered [18,19].…”

“…Indeed, inside the bend region complicated flow structures such as separation, recirculation, and secondary vortices arise, [18]. Adding rotation and channel orientation increase the complexity of the flow, resulting in different behavior if a tip or hub turn is considered [18,19]. The extended literature available on bend regions flow & losses is still not sufficient to draw conclusion of general validity to be applied for design purposes.…”

Effect of a curved turning vane on the heat transfer and fluid flow of four-pass internal cooling channels of gas turbine blades

“…Three-dimensional steady-state simulations with incompressible fluid assumptions were performed using the commercial software ANSYS Fluent. 29 Various turbulence models, including the RSM-ω, 15 K-ω SST, 22,24,27 and K-ε realizable 22 are employed to validate the computational simulation of a serpentine cooling channel with the experimental results. A comparison of the result of turbulence models and experimental data can identify the most appropriate simulation model.…”

“…The turning vane mitigates pressure loss, and upstream of the vane, the heat transfer and flow field are not remarkably affected significantly by the vane. Lei et al 27 evaluated the influences of rotation and the turning vane on the overall performance of a four-pass serpentine using numerical simulations. They concluded that under stationary conditions, the turning vane suppresses flow recirculation and increases heat transfer on the inner wall of the turning vane.…”