Cooled turbine rotor
Unsteady turbine cooling flow
- 2 NVIDIA P100 GPUs
- 4 hours per simulation
- 8 million grid nodes
Accurate simulations of cooling flows are essential for calculating the requirements of the cooling system as well as estimating the life of the high-temperature components. The prediction of the cooling flows is complicated by the presence of upstream and downstream periodic disturbances. Typically these effects would be neglected and the cooling hole configuration designed using steady simulations.
This simulation is designed to assess the impact of the unsteadiness associated with the upstream nozzle guide vane (NGV) on the downstream rotor cooling flow. It features a structured mesh of a high pressure turbine NGV and an unstructured mesh of the rotor complete with internal cooling passages and leading edge shower head cooling holes. A time-accurate unsteady simulation is compared to a steady simulation.
These results show how the rotor cooling flow is strongly influenced by the periodic passing of the upstream vane. The rotor surface temperature is both highly unsteady and also exhibits a time-average which differs significantly from that predicted by a steady calculation. The trajectory of the cooling flow also differs noticeably in the time-average compared to the steady prediction.
Turbostream allows these effects to be examined early in the design cycle, allowing the cooling system to be optimised for the real unsteady flow field in which these components will operate, as well as allowing a more accurate prediction of component life.