An indirect criterion for the laminar to turbulent flow transition in shear-driven annular liquid films. (October 2015)

• Record Type: Journal Article
• Authors: Cioncolini, Andrea; Del Col, Davide; Thome, John R.
• Is Part Of: International journal of multiphase flow. Volume 75(2015)
• Page Start: 26
• Page End: 38
• Publication Date: 2015-10
• Subjects: Laminar to turbulent flow transition -- Annular two-phase flow -- Shear-driven liquid film -- Thin liquid film -- Turbulence emergence -- Laminarization; Multiphase flow -- Periodicals; Écoulement polyphasique -- Périodiques; Multiphase flow; Periodicals; 620.1064
• DOI: 10.1016/j.ijmultiphaseflow.2015.05.002
• Languages: English
• ISSNs: 0301-9322

Abstract

Graphical abstract: Highlights: The near wall structure in shear-driven annular liquid films is resolved. The limit between the laminar sublayer and the buffer layer corresponds to ≈9 wall units. The limit between the buffer layer and the turbulent layer corresponds to ≈40 wall units. New laminar to turbulent flow transition criterion for annular liquid films. New prediction method for the average liquid film thickness. Abstract: An indirect method to identify the laminar to turbulent flow transition in shear-driven annular liquid films has been developed and used, together with literature measurements of the velocity profile, to approximately resolve the near wall structure in shear-driven annular liquid films. The limits between the laminar sublayer and the buffer layer and between the buffer layer and the turbulent layer have been found to correspond to about 9 and 40 wall units, respectively, which are higher than the corresponding limits of 5 and 30 wall units typical of single-phase boundary layers, thus indicating a weaker turbulence intensity in shear-driven annular liquid films with respect to single-phase wall-bounded flows. Additionally, a simple laminar to turbulent flow transition criterion and a prediction method for the average liquid film thickness have been developed for evaporation and condensation applications.