Transonic fan rotor

Shock oscillations on transonic fan and compressor blades can lead to severe pressure fluctuations resulting in performance penalties and dynamic loading on the structure resulting in shortened life cycle. Accurately predicting shock induced flow separation and shock oscillations using high fidelity computational fluid dynamics simulations is essential towards understanding this phenomenon at different operating points on a fan performance map.

Shock structure near design point mass flow of the transonic fan.

Full annulus simulations needed to accurately predict unsteady phenomena in turbomachines.

Transonic buffet on a single blade of a 22 blade full annulus. URANS using SA with Edwards-Chandra correction. Time-step 10^(-6) seconds. Mean shock location is close to the leading edge at the root of the blade and moves towards the trailing edge at the blade tip.

Mean pressure field and SPOD 1st mode reconstruction of the pressure perturbation at 70% span of the 22 blades in the annulus. Pressure disturbances observed circumferentially travelling at ~32% of rotational speed in the direction of fan rotation.

Jyoti Ranjan Majhi and Kartik Venkatraman (2023). Prediction and characterization of transonic buffet in an axial flow fan. In: 57th 3AF International Conference (AERO2023), Bordeaux, France, March 29-31, 2023.