Heat transfer characteristics of complex serpentine channels with leading-edge impingement in static turbine blade were investigated using the transient thermochromic liquid crystal technique under different Reynolds numbers.Distributions of local heat transfer coefficient at different positions were obtained on both pressure and suction sides.Experimental results show that:local heat transfer between two ribs is stronger than that in smooth region on inner surface of blade channels.A single heat transfer peak occurs between two adjacent ribs along the flow direction.With increase of Reynolds number

heat transfer is enhanced on all surfaces and centrifugal effect of fluid is strengthened in non-rib area downstream the bend

resulting in uneven distribution of local heat transfer there.However

ribs after the bend can reduce this effect significantly.Besides

mainstream speed changes caused by expansion and contraction of channel cross-section also influence the values and distributions of local heat transfer.