Aerodynamic Losses in Turbines with and without Film Cooling, as Influenced by Mainstream Turbulence, Surface Roughness, Airfoil Shape, and Mach Number

Table 1

Characteristics of rough surfaces employed for the symmetric airfoil investigations [8].

Surface	Λ𝑠	𝑘𝑠/𝑘	𝑘 (μm)	𝑘𝑠 (μm)	𝑘𝑠/𝑐
Large-sized roughness	15.45	1.96	64.03	125.2	0.0016
Small-sized roughness	20.10	1.89	27.92	52.59	0.0007
smooth	—	0.003	3.50	0.0094	0
Turbine blade from a utility power engine	43.460	1.640	40.820	62.300	0.00080