Steam generator tube vibrations induced by turbulent jets from baffle plates with various hole designs

This report describes the effect of jets from baffle plate flow passages on the steam generator tube vibrations. The secondary coolant passing through baffle plates generates jet turbulence in the flow. This turbulence induces vibrations which cause fretting wear and fatigue of tubes. Basic characteristics of tube vibrations are investigated experimentally using a stem generator tube with drilled hole or broach-quarterfoil type baffle plates. The results show that momentum flux of jets, throat area ratio and holedesigns of baffle plates are significant evaluating factors on tube vibrations, and influence of hole designs can be estimated derivatively from characteristics of confined cylindrical wall jets. (author)