Flow Viz
Heat/Mass Transfer

The smoke-wire flow visualization technique is a valuable tool when investigating complex flow situations. Using an array of smoke-wires, the secondary flow in a turbine passage has been shown to be composed of several, identifiable vortices. The smoke-wire traces allow us to follow the evolution of the horseshoe votices at the blade leading-edge, as they merge with other vortices, grow into the passage vortex and interact on their paths through the blade passage.

While the flow visualization yields valuable qualitative insights into the flow in turbine passages, the naphthalene mass transfer technique yields highly accurate and detailed mass transfer coefficient distributions on the blade surfaces. There is a close correspondance between the visualized secondary flow patterns and the peaks and valleys in the mass transfer coefficient distributions that are measured.

The heat/mass transfer analogy allows one to convert the mass transfer results to heat transfer results. This presentation has outlined the conversion, but there are additional aspects of the conversion that are part of the continuing work in this area.