Aero-thermal investigation of a multi-splitter axial turbine

► Experimental heat transfer results in a multi-splitter low-pressure vane are reported. ► Pneumatic taps and thin-film gauges are used in a short-duration rotating cascade. ► Boundary layer status and transition are assessed at design and off-design conditions. ► Good agreement with correlations for ducts allows detection of transition onset. ► Time-resolved data explain the interaction of vanes with the upstream rotor.