遷移域近傍において管内流の旋回が伝熱促進を引き起こす要因の考察

抄録

In this report, the factors of heat transfer enhancement by swirling the in-pipe flow around the transition regime were considered based on the measurements of spatiotemporal heat transfer and velocity field. In the turbulent regime, the centrifugal instability due to the swirl, which leads to an increase in the streamwise velocity near the wall, is considered to be one of the factors of the heat transfer enhancement against the pressure loss. This effect is considered to be larger closer to the transition regime. In the laminar regime, the turbulent transition due to instability by the swirling is considered to be the factor of a large heat transfer enhancement against the pressure loss. This effect also becomes larger closer to the transition regime.