Author(s)

WAMEEDH T. M. AL-TAMEEMI & PIERRE RICCO

Abstract

Air–water flow in a 90° sharp elbow (mitre bend) is studied in a new purpose-built experimental facility at the University of Sheffield. For the first time, the two-phase flow is investigated in a mitre bend for water-based Reynolds numbers Re_w  = 5600–12800 and water-to-air mass flow rate ratios m_w/m_a=10–3800. Four different flow patterns are observed in the upstream pipe (plug, slug, slug-annular and annular) by using a high-speed high-resolution camera. The results show that the perturbation length upstream and downstream of the elbow and the pressure drop are significantly affected by the flow patterns. Two new values of the Lockhart–Martinelli parameter C are found for the pressure drop across the elbow.

Keywords

90° sharp elbow, flow patterns, pressure drop, two-phase flow