Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 09, 2018 - September 12, 2018
Effect of expansion ratio on the backward-facing step flow is investigated experimentally. The expansion ratio ER ranges from 2.0 to 5.0. The Reynolds number Re based on the mean velocity and the hydraulic diameter of inlet channel ranges from 2.0 × 103 to 7.0 × 103. This Reynolds number range includes laminar, transition and turbulent flows. The wall static pressure coefficient Cp and Nusselt number Nu on the lower wall behind the step measured. The position where the maximum value appears in the Cp distribution moves in the downstream direction as the ER increases. However, when the position is nondimensionalized by the step height, it moves to the step side as the ER increases. When the ER is large, the dependence of Reynolds number on the pressure and the heat transfer characteristics becomes small, because the flow behind the step transitions to turbulence with low Reynolds number.
