LIFT FAN WITH DIFFUSER DUCT

A lift fan apparatus (10, 110, 210, 310) includes: a rotor (12, 112, 212) having at least one rotatable hub carrying at least one row of blades; a duct (36, 136, 236) surrounding the rotor (12, 112, 212), the duct (36, 136, 236) including spaced-apart peripheral walls extending between an inlet and an exit, the peripheral walls collectively defining a flow channel which includes a diffuser (50, 150, 250) disposed downstream of the rotor (12, 112, 212), in which a flow area at the exit is greater than a flow area at the rotor (12, 112, 212); and a plurality of spaced-apart splitters disposed in the diffuser (50, 150, 250), each of the splitters having opposed side walls extending between an upstream leading edge and a downstream trailing edge, wherein the splitters divide the diffuser (50, 150, 250) into a plurality of side-by-side flow passages (66, 166, 266, 366).