Abstract
In order to grasp the heat transfer characteristics on the bottom wall downstream of a 3-D backward-facing step, heat transfer coefficient was measured by making use of a thermo sensitive liquid crystal sheet. Reynolds numbers based on the step height were varied from 1000 to 10000 in 30 steps keeping expansion ratio and aspect ratio constant. Obtained local Nusselt number showed quite unique distribution and it suggested the strong three dimensionality of flow and thermal structures. Peak Nusselt number appears near the sidewall for every Reynolds number, namely it does not vary in the spanwise direction. However, its streamwise location moves upstream toward the step as Reynolds number increases from 1000 to 2300, and they again moves downstream as Reynolds number increases from 3000 to 10000.
