Ten Years of Passion:I.S. Gromeka’s Contribution to Science

The work and life of Ippolit Stepanovich Gromeka is reviewed. Gromeka authored a classical set of eleven papers on fluid dynamics in just ten years before a tragic illness ended his life. Sadly, he is not well known to the western scientific community because all his publications were written in Russian. He is one of the three authors who independently derived an analytical solution for accelerating laminar pipe flow. He was the first to eliminate the contradiction between the theories of Young and Laplace on capillary phenomena. He initiated the theoretical basis of helical (Beltrami) flow, and he studied the movement of cyclones and anticyclones seventeen years before Zermelo (whose work is considered as pioneering). He is also the first to analyse wave propagation in liquid-filled hoses, thereby including fluid–structure interaction.</p

Experimental data on filling and emptying of a large-scale pipeline

Laboratory-scale experiments are one of the most important means to explore the evolution of air-water interfaces and the mechanisms of pressure oscillations in pipelines during rapid filling and emptying processes. This study presents a dataset obtained from the experimental results of the flow behaviours during the pressure-gradient-driven filling and emptying processes of a large-scale pipeline. Based on these data, it is possible to study the evolution of the water-air and air-water interfaces and their breaking during pipe filling and emptying. The experimental equipment includes a variety of components (such as tanks, valves, bends, pipes of different materials and diameters, anchors, supports and water basin) and the operation procedures are rather complex. The flow behaviours are measured by various instruments; hence a thorough hydrodynamic analysis is possible. All these features and data frameworks make the current study particularly useful as a test case for real rapid filling and emptying processes and syphoning.</p

Mass shedding rate of an isolated high-speed slug propagating in a pipeline

An isolated liquid slug in the pipeline can accelerate and achieve a high speed when subjected to a driving pressure. During the slug’s high-speed movement in a pipeline, part of the liquid will shed from it resulting in changes in the slug’s mass and length. To understand the mass shedding mechanism, the mass shedding rate is studied using three-dimensional computational-fluid-dynamics methodology, in which the volume-of-fluid technique is applied to track the water–air interface and the RNG (Formula presented.) model is used to describe the turbulence. The effects of driving pressure, initial slug length, pipe inclination angle, pipe wall roughness and gravity on the slug mass shedding rate are investigated. The results show that the slug mass shedding rate is independent of driving pressure, initial slug length, pipe inclination angle and gravity, and it increases as a power function with the increase in wall roughness. It is explained from the mass shedding rate that when the slug’s traveled distance exceeds six times the initial slug length, the slug will break up. This paper solves the problem that there is no standard to select a reliable mass shedding rate for modeling the isolated high-speed slug propagating in pipelines. Highlights: Simulate the movement of an isolated liquid slug propelled by pressurized air with 3D CFD model. Propose a model for calculating the slug mass shedding rate. Study three influence factors of the slug mass shedding rate.</p

Efficient Computation of Three-Dimensional Flow in Helically Corrugated Hoses Including Swirl

In this article we propose an efficient method to compute the friction factor of helically corrugated hoses carrying flow at high Reynolds numbers. A comparison between computations of several turbulence models is made with experimental results for corrugation sizes that fall outside the range of validity of the Moody diagram. To do this efficiently we implement quasi-periodicity. Using the appropriate boundary conditions and matching body force, we only need to simulate a single period of the corrugation to find the friction factor for fully developed flow. A second technique is introduced by the construction of an appropriately twisted wedge, which allows us to furthermore reduce the problem by a further dimension while accounting for the Beltrami symmetry that is present in the full three-dimensional problem. We make a detailed analysis of the accuracy and time-saving that this novelty introduces. We show that the swirl inside the flow, which is introduced by the helical boundary, has a positive effect on the friction factor. Furthermore, we give a prediction for which corrugation angles the assumption of axisymmetry is no longer valid. It then has to make place for Beltrami-symmetry if accurate results are required

Skalak's extended theory of water hammer

Half a century ago Richard Skalak [see T.C. Skalak, A dedication in memoriam of Dr. Richard Skalak, Annual Review of Biomedical Engineering 1 (1999) 1-18] published a paper with the title "An extension of the theory of water hammer" [R. Skalak, An Extension of the Theory of Water Hammer, PhD Thesis, Faculty of Pure Science, Columbia University, New York, USA, 1954; R. Skalak, An extension of the theory of water hammer, Water Power 7/8 (1955/1956) 458-462/17-22; R. Skalak, An extension of the theory of water hammer, Transactions of the ASME 78 (1956) 105-116], which has been the basis of much subsequent work on hydraulic transients with fluid-structure interaction (FSI). The paper considers the propagation of pressure waves in liquid-filled pipes and the coupled radial/axial response of the pipe walls. In a tribute to Skalak's work, his paper is revisited and some of his less-known results are used to assess the dispersion of pressure waves in long-distance pipelines. Skalak's theory predicts that the spreading of wave fronts due to FSI is small, at most of the order of 10 pipe diameters. © 2007 Elsevier Ltd. All rights reserved.Arris S. Tijsseling, Martin F. Lambert, Angus R. Simpson, Mark L. Stephens, John P. Vítkovský, and Anton Berganthttp://www.elsevier.com/wps/find/journaldescription.cws_home/622899/description#descriptio

Parameters affecting water-hammer wave attenuation, shape and timing. Part 2: Case studies

This two-part paper investigates parameters that may significantly affect water-hammer wave attenuation, shape and timing. Possible sources that may affect the waveform predicted by classical water-hammer theory include unsteady friction, cavitation (including column separation and trapped air pockets), a number of fluid–structure interaction effects, viscoelastic behaviour of the pipe-wall material, leakages and blockages. Part 1 of this two-part paper presents the mathematical tools needed to model these sources. Part 2 of the paper presents a number of case studies showing how these modelled sources affect pressure traces in a simple reservoir-pipeline-valve system. Each case study compares the obtained results with the standard (classical) water-hammer model, from which conclusions are drawn concerning the transient behaviour of real systems.Anton Bergant, Arris S. Tijsseling, John P. Vítkovský, Dídia I. C. Covas, Angus R. Simpson and Martin F. Lamber

An overview of fluid-structure interaction experiments in single-elbow pipe systems An overview of fluid-structure interaction experiments in single-elbow pipe systems An overview of fluid-structure interaction experiments in single-elbow pipe systems

ABSTRACT Sixteen experiments carried out on liquid-filled L-shaped pipe systems are reviewed. The purpose of nearly all the experiments was to study fluid-structure interaction (FSI). The influence of loose elbows on the dynamic behaviour of liquid-filled piping systems is clearly demonstrated. This report has an educational character regarding the execution of laboratory experiments where FSI is involved.