Large Pipe Research Articles

Contribution of Large and Very Large Scale Motions to the Turbulent Kinetic energy in Turbulent Pipe Flow

AbstractIn the present investigation in turbulent pipe flow we study the contribution of turbulent structures, such as Large scale motion (LSM) and very large scale motion (VLSM) to the turbulent kinetic energy. Hence, the streamwise velocity fluctuation is measured using a single hot wire anemometer in the Cottbus Large Pipe Facility test facility (CoLaPipe) at Brandenburg University of Technology Cottbus‐Senftenberg (BTU) for Reynolds numbers Reτ = 1.3 × 104 and 1.9 × 104, where Reτ is the Reynolds number based on the friction velocity (Uτ) and the pipe diameter (D). By the use of pre‐multiplied power spectra of the streamwise velocity, we aim to understand the influence of the LSM and VLSM onto the turbulent momentum budget at different wall normal locations.

Tin Enrichment in Magmatic-Hydrothermal Environments Associated with Cassiterite Mineralization at Ardlethan, Eastern Australia: Insights from Rb-Sr and Sm-Nd Isotope Compositions in Tourmaline

Abstract Primary cassiterite mineralization is often associated with highly evolved granites, but the magmatic and hydrothermal processes that produce these deposits are often difficult to decipher. In this study, we employed the chemical and Sr-Nd isotope compositions of tourmaline to monitor processes of Sn enrichment in the magmatic and hydrothermal stages of the Ardlethan granite (Australia) and its associated Sn deposits. Initial 87Sr/86Sr (0.710–0.717) and ɛNd (–5.0 to −1.0) values of late magmatic tourmalines indicate derivation of the Ardlethan granite via an assimilation-fractional crystallization (AFC) process in which incorporation of Ordovician sediment into an I-type granitic parental magma produced an enrichment of Sn at least 30 times over that of the assumed mafic-dominated igneous source of the granite. The rare earth element and Sn concentrations of tourmaline in the greisen deposits together with δ18O of coprecipitated quartz indicate that exsolution of a late-stage, Cl-rich fluid from the Ardlethan granite led to cassiterite mineralization in these deposits. In contrast the Fe/(Fe + Mg) and initial εNd (–9.2 to −12.9) compositions of tourmaline that coprecipitated with cassiterite in the large breccia pipes adjacent to the Ardlethan granite suggest that granite-derived fluids scavenged Sn by chemical leaching of an older S-type granite that hosts the pipes. This study shows that tourmaline can act as a robust monitor of key geologic processes in complex and dynamic magmatic-hydrothermal Sn systems and that its 87Sr/86Sr and ɛNd isotope compositions are especially useful for constraining the nature of magmatic and hydrothermal sources that contributed to these deposits.

Implicitly coupled phase fraction equations for polydisperse flows

AbstractThis work presents the implementation, verification and the validation of an incompressible Eulerian multifluid model for polydisperse flows. The proposed model uses a novel monolithic, that is, implicitly coupled phase continuity equation for an arbitrary number of fluids, where the breakup source and sink terms are handled implicitly in the block‐system. The implemented model is tested for an upward bubbly flow inside a large vertical pipe. The selected flow conditions exhibit both breakup and coalescence. The grid refinement study is conducted on four structured grids with varying levels of refinement. In the validation section, the numerical results are compared to the TOPFLOW experimental measurements. The last presented test examines the performance of the novel implicitly coupled phase continuity equation to the corresponding segregated formulation and the standard segregated formulation. The performance is evaluated by comparing the conservation error over the nonlinear iterations. The presented model exhibits good agreement with the experimental measurements and gives stable results on various grids with different levels of refinement. Moreover, the implicit coupling reduces the conservation error during the calculation.

Verticality 3D Monitoring System for the Large Circular Steel Pipe

Verticality 3D Monitoring System for the Large Circular Steel Pipe

The influence of shallow buried double-line parallel rectangular pipe jacking construction on ground settlement deformation

To study the distribution characteristics and variation rules of ground subsidence. The influence law of overburden thickness is studied by 3D numerical simulation. The cumulative sedimentation of the ground decreases linearly with the increase of the thickness of the casing in the range of 0.5 times the width of the central axis of the large pipe tunnel. The cumulative settlement of the ground increases with the thickness of the casing. The thickness of the casing on both sides of the central axis of the small pipe tunnel, the superposition disturbance of the large and small pipe jackers is significantly.

Field Study on Wireless Remote Sensing for Stability Monitoring of Large Circular Steel Pipe for Marine Bridge Foundation

Field Study on Wireless Remote Sensing for Stability Monitoring of Large Circular Steel Pipe for Marine Bridge Foundation

(Invited) Increasing Biogas to Liquid Fuel Yield By Solid Oxide Co-Electrolysis of Biogas CO2 Fraction

OxEon Energy, LLC (OxEon) plans to demonstrate production of liquid hydrocarbon fuels using both the methane and CO2 generated in a food waste digester operated by the Environmental Products & Technologies Corporation (EPT). The EPT food waste digester in Burley Idaho sells produced biogas into a natural gas pipeline after separating and venting the bio-CO2. This project will convert the bio-methane to synthesis gas (syngas, as CO & H2) using a non-thermal plasma catalyzed autothermal reformer. To achieve high bio-carbon utilization, an OxEon high temperature solid oxide co-electrolysis (HTCE) system will electrochemically generate additional syngas from the bio-CO2 combined with steam raised by cooling the Fischer Tropsch (FT) reactor. Syngas from the reformed methane and co-electrolyzed CO2, will be converted to liquid fuels using an OxEon developed FT reactor. Each of the technology components have been field tested independently and will be combined for the first time in this project. The project outcome will be an engineering scale demonstration of liquid hydrocarbon bio-fuel production achieving > 50% conversion to liquids of the biogenic carbon in both CH4 & CO2 produced by an anaerobic digester.Each of the three technology elements of the integrated engineering test incorporates numerous innovations. The plasma reactor is designed to be fuel flexible, sulfur tolerant, and economically scalable to small, distributed bio-gas resources. It is also very efficient using a low power non- thermal plasma. High temperature solid oxide electrolysis has demonstrated efficiency at the thermodynamic limit as shown by analysis and testing at DOE and NASA laboratories, and is unique in its ability to co-electrolyze steam and CO2 directly to syngas. The HTCE stacks use innovations proven for the NASA Mars 2020 project which required exceptional ruggedness and effective high temperature seals. The FT reactor enables economical fabrication of smaller size synthetic fuel plants designed to match the scale of distributed renewable biomass resources. This is achieved with large diameter standard piping combined with a novel internal thermal management structure.The status of the technology elements and the planned engineering demonstration will be presented.This work is supported by the Bioenergy Technologies Office of the US Department of Energy.

Calculation of mass transfer coefficients for corrosion prediction in two-phase gas-liquid pipe flow

Internal corrosion in industrial environments involving gas-liquid flow can be a serious concern. For example, in the oil and gas industry, corrosive water phase is usually transported in pipes along with liquid and/or gas hydrocarbon phases. These gas-liquid flows develop complex flow patterns where the liquid phase can distribute in quite different ways (as stratified layers, intermittent slugs, annular film, etc.) depending on the gas and liquid flow rates and pipe inclination. In these circumstances, the water phase can flow at very high velocities leading to high turbulence and mass transfer rates that can accelerate corrosion of the metallic pipe surface. In general, proper prediction of corrosion rates via mechanistic electrochemical models requires the knowledge of the mass transfer rate of corrosive species in the aqueous phase. There are very few studies in the open literature that show specific experimental data or propose ways to compute mass transfer rates in gas-liquid flow; particularly, for large pipe diameters. The present study introduces a methodology for the estimation of mass transfer rates in gas-liquid flow via the Chilton-Colburn analogy and near-wall eddy diffusivity distribution based on the mechanistic gas-liquid flow modeling. The proposed mechanistic models cover a wide range of fluid's properties and flow rates, different flow patterns and pipe inclinations, and show good agreement with mass transfer experimental data from large-scale gas-liquid flow.

Predicting non-deposition sediment transport in sewer pipes using Random forest

Sediment transport in sewers has been extensively studied in the past. This paper aims to propose a new method for predicting the self-cleansing velocity required to avoid permanent deposition of material in sewer pipes. The new Random Forest (RF) based model was implemented using experimental data collected from the literature. The accuracy of the developed model was evaluated and compared with ten promising literature models using multiple observed datasets. The results obtained demonstrate that the RF model is able to make predictions with high accuracy for the whole dataset used. These predictions clearly outperform predictions made by other models, especially for the case of non-deposition with deposited bed criterion that is used for designing large sewer pipes. The volumetric sediment concentration was identified as the most important parameter for predicting self-cleansing velocity.

Assessment of external corrosion deterioration of large diameter metallic water pipes buried in reclaimed land

Assessment of external corrosion deterioration of large diameter metallic water pipes buried in reclaimed land

State of watermain infrastructure: a Canadian case study using historic pipe break datasets

Over the last two decades, a variety of reports have suggested that watermains in Canada are deteriorating, and break rates are increasing. However, these reports are often limited as the years of break records being utilized are brief; this paper revisits those assessments using over 45 years of break records and shows that three of the five utilities investigated are experiencing significant decreases in break rates over the past 10 years while the two other utilities are maintaining consistent break rates. These results indicate that these utilities are effectively managing their watermain infrastructure, and suggest watermain infrastructure throughout Canada may be performing better than suggested by cross-sectional survey results. Analyses indicate that on average, 22% of the watermains analyzed have exceeded the 0.125 breaks per km per year break rate threshold and may be considered for pipe replacement or rehabilitation. In particular, 50% of cast iron pipes installed post-WWII have exceeded a break rate threshold of 0.125 brks/km/year, suggesting large pipe replacement or rehabilitation of this pipe cohort is required.

Hydraulic analysis of gate valve using computational fluid dynamics (CFD)

As a very important element of most water supply systems, valves are exposed to the effects of strong hydrodynamic forces. When exposed to large physical quantities, the valve and piping can be damaged, which could endanger the performance of a water supply system. This is the main reason why it is necessary to foresee and determine the maximum values of velocity, pressure and other physical quantities that can occur in the system under certain conditions. Predicting extreme conditions allows us to correctly size the valve for the expected conditions to which the valve might be exposed, which is also the main objective of this paper. One of the methods for predicting and determining extreme values on a valve is to perform a simulation with computational fluid dynamics (CFD). This is exactly the method used in the preparation of this paper with the aim of gaining insight into the physical magnitudes for models of gate valves positioned inside a pipe under characteristic degrees of valve closure. The Ansys CFX 19.1 and Ansys Fluent 19.1 software was used to simulate the hydrodynamic analysis and obtain the required results. The hydrodynamic analysis was performed for four opening degrees of gate valve

Validation of interfacial area concentration model for simulating bubbly and cap/slug flow behaviors in large diameter pipes using LSTF, ATLAS, and horizontal pipe experiment data

This study discusses Interfacial Area Concentration (IAC) models developed for bubbly and cap/slug flow regimes in a large diameter pipe incorporating recently developed small bubble fraction correlations in various flow conditions. The main focus of this study was the robust simulation of the behaviors of bubbly and cap/slug flows in large diameter pipes observed in Large Scale Test Facility (LSTF), Advanced Thermal-hydraulic test Loop for Accident Simulation (ATLAS), and horizontal flow test facility. Since the IAC was one of the key parameters to achieve this, an IAC model for large diameter pipes was first derived based on the existing Hibiki-Ishii IAC model for bubbly flow, and the Shen-Hibiki IAC model for cap bubbly-to-churn flow. The volume fraction of group-1 bubbles, i.e., small spherical bubbles, in the IAC model, which have been developed based on the assumption that the group-1 bubbles exponentially decay in the slug flow regime, was refined. As a result, a more physical model of the group-1 bubble number density that remains constant in the cap/slug flow regime was imposed for large diameter pipes. The validity of the IAC model for large diameter pipes in predicting the interfacial drag force between gas and liquid phases in large pipes of multiple test facilities was then examined. The validation of the proposed IAC model was conducted through simulations of 1) the loss of Residual Heat Removal (RHR) during the mid-loop operation of the LSTF, 2) the 6-inch Small Break Loss of Coolant Accident (SBLOCA) of the ATLAS, and 3) the two-phase flow behaviors under a wide range of fluid conditions in the horizontal pipe test facility. Improved results were obtained with the proposed model as it indicated that there was good agreement between the calculated results and the experimental data throughout the whole transient.

Review and recommendations for structural testing of buried gravity storm drain pipes and culverts

Buried pipes are important components of the underground infrastructure. Structural failure of these pipes is costly, socially and environmentally disruptive. To prevent such incidents, a deep understanding of the soil–pipe interaction system behavior is needed. Currently, two common standard methods are available for the structural testing of pipes: parallel-plate loading test and three-edge bearing test, in which the effects of surrounding soil and distributed load on the pipe sample are ignored. However, in the available design methodologies the effect of bedding and load distribution is considered though empirical factors. As of today, there is no standard test method available for structural testing of pipes considering the effect of soil–pipe interaction system. Therefore, the objectives of this paper are to present a literature review of full-scale structural testing methods of relatively large diameter gravity pipes ranging from 36 in (90 cm) and larger, and suggest a general soil–pipe test procedure for structural evaluation of large diameter gravity pipes, such as culverts. Discussions are made for selection of a soil–pipe structural testing condition, loading method, loading rate, loading configurations, and required instrumentations for capturing and recording test results.

Comparison of Two Different Sized Small-Break LOCAs on the Passive Safety Injection Line Using SMART-ITL Data

Even for small modular reactors (SMRs) with all large pipes removed, a small-break loss-of-coolant accident (SBLOCA) is an important design-basis accident (DBA). Experimental simulation of the SBLOCA scenario is essential before a prototype reactor is realized. The system-integrated modular advanced reactor (SMART) is one of the SMRs developed by the Korea Atomic Energy Research Institute. An integral test loop, SMART-ITL, was also constructed to carry out several types of integral thermal-hydraulic effects tests for the prototype reactor. The SMART-ITL was designed with a preserved height, 1/7th diameter, and 1/49th area, and volume-scaling ratios. Two types of passive safety systems were equipped in the SMART-ITL: a passive safety injection system (PSIS) and a passive residual heat removal system (PRHRS). The PSIS was designed to refill the coolant in the reactor coolant system (RCS) for 72 h after an accident. Under accident conditions the PRHRS prevents overheating and overpressurization of the RCS using two-phase natural circulation. The SBLOCA on the passive safety injection line is a significant DBA that should be validated for differences in break size. In this paper, the effects of two different break sizes, 2 and 7/32 in., were analyzed in order to study the effect of the maximum and minimum mass and energy loss of the RCS. In order to simulate a clear difference between maximum and minimum mass and energy loss of the RCS, heat removal by the PRHRS was performed in the maximum break size (2-in.) accident, and heat removal by the PRHRS was not conducted in the minimum break size (7/32-in.) accident. The difference in mass and energy loss of the RCS will have a significant impact on the operation of the automatic depressurization system. Using the two extreme accident simulations, it was possible to confirm the difference in accident progression caused by the difference in break size and the characteristics of the PSIS.

A Study on the Difference in Ballasting Time Arising from the Installation of an Ultraviolet Ballast Water Management System on Existing Ships

This study quantitatively investigated the increase in ballasting time through numerical calculations when an ultraviolet (UV) ballast water management system (BWMS) is installed on an existing vessel. The calculation results indicate that the ballasting time of a gas carrier having 55,000 dead weight tonnage was 2.152 hours without installation of the UV BWMS and implementation of a flow control function. Ballasting time increased by 14.2% after installing the UV BWMS, and it increased by 20.4% with both its installation and implementation of a flow control function. If actual conditions are taken into account, ballasting time after installing the UV BWMS is estimated to increase by at least 30% compared with current ballasting time. Therefore, when concerned parties select a UV type BWMS, it is advisable for them to minimize ship operation losses from an increase in ballasting time by considering the capacity of the actual ballast pumps on board and the flow energy loss of the UV BWMS. Additionally, it is recommended that a BWMS with larger capacity, larger pipes, and pipes with inside coatings be used to minimize the increase in ballasting time after installation of the BWMS.

Thermobarometry and Geochemistry of Mantle Xenoliths from Zapolyarnaya Pipe, Upper Muna Field, Yakutia: Implications for Mantle Layering, Interaction with Plume Melts and Diamond Grade

Minerals from mantle xenoliths in the Zapolyarnaya pipe in the Upper Muna field, Russia and from mineral separates from other large diamondiferous kimberlite pipes in this field (Deimos, Novinka and Komsomolskaya-Magnitnaya) were studied with EPMA and LA-ICP-MS. All pipes contain very high proportions of sub-calcic garnets. Zapolyarnaya contains mainly dunitic xenoliths with veinlets of garnets, phlogopites and Fe-rich pyroxenes similar in composition to those from sheared peridotites. PT estimates for the clinopyroxenes trace the convective inflection of the geotherm (40–45 mW·m−2) to 8 GPa, inflected at 6 GPa and overlapping with PT estimates for ilmenites derived from protokimberlites. The Upper Muna mantle lithosphere includes dunite channels from 8 to 2 GPa, which were favorable for melt movement. The primary layering deduced from the fluctuations of CaO in garnets was smoothed by the refertilization events, which formed additional pyroxenes. Clinopyroxenes from the Novinka and Komsomolskaya-Magnitnaya pipes show a more linear geotherm and three branches in the P-Fe# plot from the lithosphere base to the Moho, suggesting several episodes of pervasive melt percolation. Clinopyroxenes from Zapolyarnaya are divided into four groups according to thermobarometry and trace element patterns, which show a stepwise increase of REE and incompatible elements. Lower pressure groups including dunitic garnets have elevated REE with peaks in Rb, Th, Nb, Sr, Zr, and U, suggesting mixing of the parental protokimberlitic melts with partially melted metasomatic veins of ancient subduction origin. At least two stages of melt percolation formed the inclined PT paths: (1) an ancient garnet semi-advective geotherm (35–45 mW·m−2) formed by volatile-rich melts during the major late Archean event of lithosphere growth; and (2) a hotter megacrystic PT path (Cpx-Ilm) formed by feeding systems for kimberlite eruptions (40–45 mW·m−2). Ilmenite PT estimates trace three separate PT trajectories, suggesting a multistage process associated with metasomatism and formation of the Cpx-Phl veinlets in dunites. Heating associated with intrusions of protokimberlite caused reactivation of the mantle metasomatites rich in H2O and alkali metals and possibly favored the growth of large megacrystalline diamonds.

Experimental and numerical study of pressure drop in pipes packed with large particles

This study investigates the pressure drop in horizontal pipes packed with large particles that result in small pipe-to-particle diameter ratio both experimentally and numerically. Two horizontal pipes of 0.1905 and 0.0254 m ID filled with cylindrical or spherical particles are used to collect the experimental data for single and two-phase flows. The porosity has same value for both pipes when they packed with cylindrical particles which is 0.75, however has different values when packed with spherical particles, 0.7 for the large pipe and 0.57 for the small pipe. The Roe-type Riemann solver proposed by Santim and Rosa Int J Numer Methods Fluids 80 (9), 536–568, [36] which uses the Drift-Flux model is modified aiming to predict the pressure drop in porous media through the implementation of a new source term in the system of equations. Empirical models available in the literature are used to calculate the single and two-phase flows pressure drop. The motivation is to verify the solver capability to reproduce the two-phase flow pressure drop in porous media and to compare some empirical models existing in the literature against the experimental data provided modifying some empirical coefficients when necessary.

Transient Phenomena Generated in Emptying Operations in Large-Scale Hydraulic Pipelines

Air pockets generated during emptying operations in pressurized hydraulic systems cause significant pressure drops inside pipes. To avoid these sudden pressure changes, one of the most widely used methods involves the installation of air valves along the pipeline route. These elements allow air exchange between the exterior and the interior of the pipe, which alleviates the pressure drops produced and thus prevents possible breaks or failures in the structure of the installation. This study uses a mathematical model previously validated by the authors in smaller installations to simulate all hydraulic variables involved in emptying processes over time. The purpose of these simulations is the validation of the mathematical model in real large-scale installations, and to do this, the results obtained with the mathematical model are compared with actual measurements made by the partner company. The hydraulic system selected for the study is a pipeline with a nominal diameter of 400 mm and a total length of 1020 m. The results obtained from the mathematical model show great similarity with the experimental measurements, thus validating the model for emptying large pipes.

Elutriation pipes in ignimbrites: An analysis of concepts based on the Huichapan Ignimbrite, Mexico

The upper portion of the Huichapan Ignimbrite (UHI), central Mexico, is a non-welded massive ignimbrite characterized by large and well-developed fines-poor elutriation pipes. We conclude that the most important pipe-forming process in the Huichapan Ignimbrite was deposition-triggered aggregative-type segregation, and this process is enhanced by positive pore-pressure feedback during the rapid settling of the pyroclastic material. In experiments, pumice concentration zones and elutriation pipes have been formed in separated portions of the deposits. Contrary to the experimental results, in the UHI both pumice concentration zones and elutriation pipes have been observed alongside one another within the deposit. We interpret this association to have formed during time periods of unusually high deposition rate within a long-lived, sustained pyroclastic density current system. Elutriation pipes were formed because of low shearing and vertical channeling of gases, and the pumice concentration zones formed because of pumice segregation during hindered settling. Nevertheless, the deposition rate was so high that the segregated pumice was “frozen” before it could bypass, within the deposit, right next to the elutriation pipes. We present a classification scheme of five types of elutriation pipes based on our field observations in the UHI and a review of field and experimental work from other authors: 1) tubular pipes; 2) irregular tubular pipes; 3) anastomosing pipes; 4) pinch-out pipes; 5) deflected pipes. Irregular tubular pipes are the most common in the volcanic geological record and they form because of deposition-triggered aggregative-type segregation and/or post-depositional upward fluid flow. Likely, anastomosing elutriation pipes are a unique product of deposition-triggered aggregative-type segregation. A comparison between the lower and upper portion of the Huichapan Ignimbrite leads to the conclusion that deposition-triggered pipe formation is enhanced by poor sorting, low shearing, and presence of large clasts (>−5Φ, 32 mm). Pipe-free ignimbrites in the volcanic geological record likely come from relatively better-sorted dispersions with few coarse clasts, but more importantly, strong shearing during deposition may be the main processes that diminish pipe formation.