Abstract: Adoption the advanced LDV measurement, experimental investigation on cross-flow fans performance on steady and stall conditions are conducted using three rotors of fans with different constructral sizes and but good geometrical similarity, to study similarity and difference of internal flow in cross-flow fans. Based on the data obtained from experiments, the distinctive forming process of the eccentric vortex in the cross-flow fan is analyzed theoretically. From the analysis the rules are put forward on how to be changed the important parameters and the positions of the vortex at the different volume flows.

Key words: Cross-flow fan, Eccentric vortex, Internal flow, LDV measurement