One-dimensional unsteady Reynolds-averaged Navier–Stokes computations were performed for oscillatory transitional and turbulent pipe flows the results validated against existing experimental data a wide variety of Reynolds Womersley numbers. An version Johnson–King model was implemented with optional near-wall modification to account temporal pressure gradient variations, predictions compared t...

Deepwater and ultra-deepwater oil gas exploitation might be challenge due to the fatigue damage at touchdown zone (TDZ). Therefore, development of risers with thicker pipe ends (upset end) is a solution diminish issues related through reducing average axial stress. In current study, manufacturing an upset end was carried out by friction welding in API X65 PLS2 steel outer diameter 220 mm. Consi...

Over time, oil pipes are scaled, which causes problems such as a reduction in the effective diameter of pipe, an efficiency reduction, waste energy, etc. Determining exact value scale inside pipe is very important order to take timely action and prevent mentioned problems. One accurate detection methodology use non-invasive systems based on gamma-ray attenuation. For this purpose, research, thi...

Three-dimensional travelling wave solutions are found for pressure-driven fluid flow through a circular pipe. They consist of three well-defined flow features streamwise rolls and streaks which dominate and streamwise-dependent wavy structures. The travelling waves can be classified by the m-fold rotational symmetry they possess about the pipe axis with m = 1, 2, 3, 4, 5 and 6 solutions identif...

Different failure modes should be carefully analyzed to effectively design the pipe-in-pipe (PIP) repair systems rehabilitate natural gas and water pipelines in place service. This study characterizes through analytical numerical modelling of different performance objectives have a comprehensive understanding overall behavior PIP with range thicknesses elastic moduli. It focused on assessing st...

The results of an experimental investigation into the threshold boundary between laminar and disordered pipe flow are presented. Complex features have been uncovered using a highly refined experimental approach where an intermediate periodic state forms an integral part of the transition sequence. In accord with the suggestions produced by a numerical investigation, the boundary is found to be ...

Fluid flow, heat transfer and entropy generation characteristics of micro-pipes are investigated computationally by considering the simultaneous effects of pipe diameter, wall heat flux and Reynolds number in detail. Variable fluid property continuity, Navier-Stokes and energy equations are numerically handled for wide ranges of pipe diameter (d = 0.50–1.00 mm), wall heat flux ( ' ' q = 1000–20...

Multipactor in beam-pipe transitions of superconducting RF cavities can be explained using RF potential well theory [1]. In this paper we present simulation results supporting this explanation for both RF cavities and transmission lines. INTRODUCTION Curved-shaped transition regions between a cavity and a beam pipe were thought to be multipactor-free. Thus recent experimental observations of mu...

The transition to turbulence exhibits remarkable spatio-temporal behavior that continues to defy detailed understanding. Near the onset to turbulence in pipes, transient turbulent regions decay either directly or, at higher Reynolds numbers through splitting, with characteristic time-scales that exhibit a super-exponential dependence on Reynolds number. Here we report numerical simulations of t...