Abrasive flow finishing characteristics of internal cooling channel of turbine blade

Abstract

The internal multi cooling channels of aviation turbine blades, mostly processed by lost foam casting, have high surface roughness, low cooling efficiency, small internal channel section and S-shaped bending and narrow distribution, and are not easy to polish. The Polyflow software is used to simulate the internal cooling channel of blade, and the changes of internal pressure field and velocity field are studied. The workpiece with S-shaped inner runner was machined and tested to study the variation law of surface roughness and material removal in four typical areas of the workpiece. The results show that the pressure drop decreases along the flow direction and the velocity decreases from the center of the channel to the wall; under the same test conditions, the surface roughness at the turning of S-shaped channel is lower than that at the straight channel; there is pressure loss along the flow path, and the material removal in area A is 4～5 times greater than that in area D.

Keywords

• abrasive flow machining
• turbine blades
• s-shaped runners
• polyflow simulation
• internal cooling channels