The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

Table 3

Prototype and full size double ended motor tunnel ventilation fan specification.

	Prototype fan	Full size fan
Diameter (metres)	1.8	2.8
Hub ratio	0.44	0.40
Tip solidity	0.5	0.5
Blade number	16	20
Running speed (RPM)	990	890
Blade passing frequency (Hz)	264	297