1359-4311/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.applthermaleng.2009.07.016 * Corresponding author. Tel.: +91 4422574680; fax E-mail address: [email protected] (A.R. Balakrishna This paper reports a study of heat transfer in the post-critical heat flux (post-CHF) regime under forced convective upflow conditions in a uniformly heated vertical tube of 12.7 mm internal diameter and ...

We report experimental measurements of density waves in granular materials flowing down in a capillary tube. The density wave regime occurs at intermediate flow rates between a low density free fall regime and a high compactness slower flow. We observe this intermediate state when the ratio of the tube diameter and the particles size lies between 6 and 30. The propagation velocity of the waves ...