SPLITTER EFFECT IN CONICAL DIFFUSERS. PART I. EXPERIMENTAL PHASE INCOMPRESSIBLE FLOW,

The effects of a ring-airfoil used as a splitter in a conical diffuser were critically examined. The influence of a ringairfoil on a turbulence intensity and boundary layer profile at the diffuser inlet, b velocity distributions across the diffuser at stations along the main flow direction, c the growth of boundary layer and the velocity gradient at the diffuser wall and d the pressure field inside the diffuser, are presented and discussed. The conclusions of this investigation are 1 The diffuser performance improvement was attributed to the induced velocity around the airfoil, which modified the pressure field inside the diffuser. 2 The diffuser inlet velocity profile and turbulence intensity were very secondary effects. The experimental results were summarized in a partial performance map, which can be used as a designers guide. The map shows that diffuser pressure recovery efficiency can be increased from 55 to 72, and improvement of 31 by placing a thin, ring-airfoil in the diffuser as a splitter. Author