A centrifugal fan has rotor internal and external diameters ! = 500 mm and " = 750 mm. The diameter of the rotor eye is ( = 450 mm. The rotor has 10 blades with thickness = 4 mm. Blades are simply curved with width ! = 180 mm at the inlet and " = 150 mm at the outlet. There is no pre- swirl. Blade angles at inlet and outlet are ! ) = 60 and " ) = 45 . The fan runs at 1450 rpm and delivers the volume flow rate = 4 m3/s ( * = 1.2 kg/m3). Assume that volumetric efficiency is + = 0.95 and the incidence loss coefficient at rotor inlet is ,-. = 0.80. Apply Pfleiderer's formulae to estimate the slip, with = 0.75.Determine the velocity triangles just upstream of the rotor inlet (section 1) and just downstream of the rotor inlet