Axial gap is an important structural parameter of the axial fan

so investigating the influence mechanism of axial gap on rotating stall if of great significance.Based on the Realizable k-εturbulence model

the unsteady evolution process of the stall condition of an axial fan was numerically simulated by software Fluent

under conditions with different axial gaps.The results show that

under the near stall condition

the pressure coefficient at the leading edge and trailing edge of pressure surface decreases rapidly along the streamwise direction.The stall inception first appears in the tip region of the rotor

and the number of channels occupied by the stall inception increases along with the axial gaps broadening.The high turbulent kinetic energy area and numer gets larger and greater as the axial gap enlarges.The pressure decreases with the increasing axial gap at relative position of the Rotor2.