Dr. Buddhika2026-06-082026-06-08https://dspace.academy.edu.ly/handle/123456789/2214The phase distributions within the pipes were measured using Electrical Capacitance Tomography (ECT) and Wire Mesh Sensors (WMS). The behaviour of the flow was examined qualitatively using high speed imaging. To study the flow development in the riser, both ECT and WMS were placed in series and moved along three axial locations downstream of the mixing section. During the experiments at the bends, the ECT was kept immediately upstream while the WMS was moved to different positions downstream of the bend.Considering the gap in available information and the need of the industries such as oil and gas production, energy, and food processing, this study focuses on the two-phase flows around bends in process pipelines. The aim of this study is to investigate the influence of 90° bends on the gas-liquid two phase flow behaviour in vertical and horizontal orientations using advanced two-phase flow measuring techniques. An experimental study has been conducted using silicone oil with a viscosity of 5 mPa.s and air to examine the transitional flows around 90° bends of 68 mm internal diameter (ID) with different configurations. Experiments were conducted at ambient conditions in an open system which consists of a 68 mm ID riser of 4.5 m long, vertical upward 90° bend and two horizontal sections of a 9.2m and 5.5m long in series with a horizontal 90° bend in between. The experimental matrix comprises 60 combinations of gas and liquid superficial velocities, ranging from 0.045 m.s-1 to 3.21 m.s-1 and 0.15 m.s-1 to 0.53 m.s-1 respectivelytwo-phase flow around 90° bends