The Design Method of Axial Flow Runners Focusing on Axial Flow Velocity Uniformization and Its Application to an Ultra-Small Axial Flow Hydraulic Turbine

Table 1

Specifications of test runners.

		Hub	Mid	Tip
Original	Radius [mm]	15.1	24.6	34.1
	Solidity	1.04	0.72	0.57
	Blade angle [°]	16.9	21.0	24.7
	Airfoil	MEL031
	Blade number	4
Case 1	Radius [mm]	15.1	24.6	34.1
	Solidity	0.97	0.72	0.58
	Blade angle [°]	31.7	27.8	31.0
	Airfoil	MEL031
	Blade number	4
Case 2	Radius [mm]	15.1	24.6	34.1
	Solidity	0.95	0.72	0.59
	Blade angle [°]	36.4	19.1	11.3
	Airfoil	MEL031
	Blade number	4
Case 3	Radius [mm]	15.1	24.6	34.1
	Solidity	0.95	0.73	0.60
	Blade angle [°]	38.0	17.0	7.6
	Airfoil	MEL031
	Blade number	4