Mist/steam heat transfer in confined slot jet impingement

Internal mist/steam blade cooling technology has been considered for the future generation of Advanced Turbine Systems (ATS). Fine water droplets of about 5 mum were carried by steam through a single slot, jet onto a heated target surface in a confined channel. Experiments covered Reynolds numbers from 7500 to 25 000 and heat fluxes from 3 to 21 kW/m(2) The experimental results indicate that the cooling is enhanced significantly near the stagnation point by the mist, decreasing to a negligible level at a distance of six jet widths from the stagnation region. Up to 200 percent heat transfer enhancement at the stagnation point was achieved by injecting only similar to1.5 percent of mist. The investigation has focused on the effects of wall temperature, mist concentration, and Reynolds number.