曲り流路内乱流拡散火炎の熱輸送特性(熱工学, 内燃機関, 動力など)

抄録

Heat transport characteristics of a non-premixed turbulent flame formed in a curved rectangular duct (180° bend) are investigated experimentally. Key turbulence quantities of velocity and thermal fields such as Reynolds stress components and turbulent heat fluxes are measured using a combined LDV and fine-wire thermocouple technique. These measurements show direct evidence of the occurrence of counter-gradient heat transport, which can be ascribed to the existence of a strong pressure gradient in the radial direction of the curved duct. The schlieren photography for visualizing the density field reveals totally different behavior of the burned gas parcels between the high- and the low-pressure sides of the flow, and the observations may help us explain the mechanism of the occurrence of the counter-gradient heat transport in turbulent flows with combustion.