Characteristics of Pulsating Flow in Pipes

Heat transfer characteristics of pulsating turbulent air ow in a pipe heated at uniform heat ux were experimentally investigated. The experiments were performed over a range of 10000 Re 40000 and 6.6f68 Hz. This situation nds applications in modern power generation facilities and industrial pro- cesses. With installing the oscillator downstream of the tested tube exit, results showed that Nu is strongly affected by both pulsation frequency and Reynolds number. Its local value either increases or decreases over the steady ow value. The variation is more pronounced in the entrance region than that in the downstream fully developed region. It is observed also that the relative mean Nu either increases or decreases, depending on the frequency range. Although the deviations are small, it seems to be obvious at higher values of Reynolds number. The obtained heat transfer results are classi ed according to turbulent bursting model and looked to be qualitatively consistent with previous investigations.

Autorentext

I am Lecturer Assistant in Mechanical Power Engineering Department, Egypt. I have MSc in Mechanical Engineering, in the subject of Heat Transfer and Fluid Dynamics.

Klappentext

Heat transfer characteristics of pulsating turbulent air ow in a pipe heated at uniform heat ux were experimentally investigated. The experiments were performed over a range of 10000 Re 40000 and 6.6f68 Hz. This situation nds applications in modern power generation facilities and industrial pro- cesses. With installing the oscillator downstream of the tested tube exit, results showed that Nu is strongly affected by both pulsation frequency and Reynolds number. Its local value either increases or decreases over the steady ow value. The variation is more pronounced in the entrance region than that in the downstream fully developed region. It is observed also that the relative mean Nu either increases or decreases, depending on the frequency range. Although the deviations are small, it seems to be obvious at higher values of Reynolds number. The obtained heat transfer results are classi ed according to turbulent bursting model and looked to be qualitatively consistent with previous investigations.