To investigate the effects of internal surface roughness of precision casting turbine blade on heat transfer of pin-fin with lamilloy structure

the heat transfer coefficient of the pin in typical lamilloy were simulated

with internal surface roughness of 0 μm

10 μm

20 μm and 30 μm

at Reynolds number range from 1× 10~4 to 5× 10~4. The results show that

the influence of the internal surface roughness on heat transfer of the pin-fin mostly concentrates on the windward side. The average heat transfer coefficient on the pin increases with the surface roughness

and this influence becomes more obvious as the Reynolds number increases. When the Reynolds number varies from 1× 10~4 to 5× 10~4

the area-averaged heat transfer coefficient on the pin-fin with internal surface roughness of 30 μm are 13% to 134% higher than that on the smooth pin.