Experimental study of heat transfer in pulsating turbulent flow in a pipe

• Published in: The International journal of heat and fluid flow 2008-08, Vol.29 (4), p.1029-1038
• Main Authors: Elshafei, Elsayed A.M., Safwat Mohamed, M., Mansour, H., Sakr, M.
• Format: Article
• Language: English
• Subjects: Convective and constrained heat transfer; Convective heat transfer; Exact sciences and technology; Flows in ducts, channels, nozzles, and conduits; Fluid dynamics; Fundamental areas of phenomenology (including applications); Heat transfer; Hydrodynamic waves; Physics; Pulsating flow in a pipe; Turbulent flow
• ISSN: 0142-727X; 1879-2278
• DOI: 10.1016/j.ijheatfluidflow.2008.03.018

Heat transfer characteristics of pulsating turbulent air flow in a pipe heated at uniform heat flux were experimentally investigated. The experiments were performed over a range of 10 4 < Re < 4 × 10 4 and 6.6 ⩽ f ⩽ 68 Hz. This situation finds applications in modern power generation facilities and industrial processes. 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 flow 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 classified according to turbulent bursting model and looked to be qualitatively consistent with previous investigations.