Wyniki wyszukiwania - BazTech

1

Innovative Suction Anchor System (SAFL) with Extendable Fastening Legs: Design, Prototype Development, and Initial Field Testing in Soft Seabed Environments

Rutkowski G., Jaskulska O.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2026

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Vol. 20 No. 1

217--222

EN

The article introduces the innovative seabed anchor system SAFL (Suction Anchor with extendable Fastening Legs) and presents the results of the research team’s initial tests. Traditional seabed anchors often struggle to maintain stability in soft seabed environments, limiting their effectiveness in various marine applications. This breakthrough system is specifically designed for anchoring objects in such conditions. The project aims to develop an anchor that, once embedded in the seabed, deploys lateral, extendable legs to significantly enhance its holding capacity. The research team successfully developed a SAFL anchor prototype and conducted preliminary field tests. The initial results not only demonstrate the effectiveness of the SAFL system but also lay the groundwork for significant advancements in marine engineering and offshore construction, enabling more reliable and efficient anchoring solutions for a wide range of marine applications

2

Effect of Perforated Baffle Shapes on Sloshing Reduction in Prismatic Tanks Using SPH Analysis

Trimulyono A., Riadi N.A., Mulyatno I.P., Chrismianto D., Iqbal M., Firdhaus A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2026

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Vol. 20 No. 1

167--171

EN

Sloshing is a phenomenon that is nonlinear in a liquid carrier, such as LNG or a tanker ship. One type of LNG carrier is the membrane-type carrier. The membrane type is similar to a prismatic tank, whose shape is suitable for a ship. This paper investigates the mitigation of sloshing in a prismatic tank by implementing a perforated baffle. There are four models of perforated baffle circles, rectangular, long ellipsoid, and short ellipsoid. The baffle position is at the midpoint of the tank, with a longitudinal position to suppress fluid in rolling motion. The filling ratios of the tank are 25% and 50%, mimicking experimental conditions with the excitation force rolling. The pressure sensor located near the free surface in 25% filling ratio was used to validate and verify the numerical approach of smoothed particle hydrodynamics (SPH). SPH is one of the numerical approaches for computational fluid dynamics (CFD) based on the particle method, which is suitable for large deformations and nonlinear free surface flows, such as sloshing. The dynamic pressure and free surface deformation after installation of the perforated baffle significantly decreased and proved the perforated baffle design suitable for the prismatic tank.

3

An Innovative Approach to the Problem of Transporting Spoil from Great Depths in Deep-Sea Mining

Filipek Wiktor, Broda Krzysztof, Tora Barbara

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2025

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Vol. 19 No. 1

229--234

EN

The article presents an innovative approach to one of the key challenges in offshore mining – transporting ore from the seabed to the surface. Traditional methods, such as CLB (with continuareline bucket), HP (hydraulic pumping), ALP (air-lift pumping) or hybrid techniques, are associated with high energy consumption and high operating and environmental costs. To adddress these limitations, the authors propose an alternative solution based on the use of physicochemical phenomena, which significantly reduces energy consumption. The starting point is the analysis of basic physical principles, such as potential energy or the buoyancy principle, in the context of the aquatic environment and high pressure conditions at great depths. The authors consider the use of the natural properties of the working medium as a source of power for the ascent process, as well as the potential for energy recovery, which enhances the energy balance and the transport system’s efficiency. The article presents the results of theoretical and simulation studies, which have laid foundation for numerous patents and scientific publications. The authors emphasize the practical potential of the proposed solutions, indicating at the same time the need for further work on their implementation in real-world conditions.

4

Optimising the Operation of Ships with Artificial Intelligence Systems

Bolkvadze Nugzar, Verdzadze Ruslan, Bazaian Aram, Bolkvadze Levan, Gabedava George

Polish Maritime Research

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2025

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nr 4

119--131

EN

The objective of this study was to conduct an empirical evaluation of the effectiveness of artificial intelligence systems in optimising the operation of commercial maritime vessels. The methodology involved collecting and processing telemetry from 58 synchronised onboard measurement channels, including temperatures, vibration metrics, gyroscopic data, trim and heel angles, and data from automatic identification systems, differential global positioning systems, and radar signals. Data were sampled at intervals of 1 s, filtered using the Hampel method, and aggregated into frames of 3 min. A hybrid deep learning model was developed to forecast vessel speed, fuel usage, and stability. Experiments were conducted on 16 vessels: six container carriers (3,000 20-foot equivalent units class) and 10 Handymax bulk carriers (40,000–55,000 deadweight tons). These vessels completed 97 voyages between March 2023 and February 2024, 45% of which took place in the Black Sea and 55% in the North Sea. A validation campaign comprising 9,230 h of simulator trials and real-world deployment was carried out to test the artificial intelligence model under variable sea states and in scenarios involving disruptions to automatic identification and differential global positioning systems. The results showed a 12.4% reduction in average fuel consumption and an 8.2% decrease in voyage duration. Ship stability improved, with a 22% reduction in roll amplitude. Predictive maintenance algorithms achieved 95% accuracy, enabling early fault detection and reducing unscheduled downtime. Only three manual interventions were recorded during deployment, and course deviations remained below 1.3°. An environmental analysis revealed a 4.2% improvement in carbon intensity, demonstrating compliance with the International Maritime Organization Carbon Intensity Indicator standards.

5

Hydrofoil Installation and Performance Optimisation for Ship Resistance Reduction in Trimaran Through Particle Swarm Optimisation Method

Ghadimi Aliakbar, Ghadimi Parviz, Ghassemi Hassan

Polish Maritime Research

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2025

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nr 1

54--63

EN

The trimaran vessel performs well both in calm waters and in waves. To improve its hydrodynamic efficiency, a hydrofoil is installed at the rear part of the trimaran. The primary aim of this hydrofoil is to reduce the overall resistance while the ship is moving. This study focuses on minimising the ship’s total resistance. An optimisation process is designed to determine the best position and angle of attack (AoA) for the hydrofoil at the design speed. To achieve this, a multi-disciplinary optimisation (MDO) platform is employed to conduct a computation fluid dynamics (CFD)-based automated design study. The optimisation method integrates STAR-CCM+ software with the particle swarm optimisation (PSO) algorithm as the optimiser. The flow field and wave patterns around the trimaran are analysed to assess resistance improvements. The results reveal that the optimal position for the NACA6612 hydrofoil is towards the stern and away from the midship, with the ideal AoA being 5.19 degrees at cruising speed. Comparisons indicate that the resistance of the trimaran with the optimised hydrofoil is reduced by approximately 4.49% compared to a trimaran without the hydrofoil.

6

Development and validation of a high-resolution hydrodynamic model for the Polish Marine Area

Dybowski Dawid, Janecki Maciej, Nowicki Artur, Jakacki Jaromir, Dzierzbicka-Głowacka Lidia

Oceanologia

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2025

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No. 67 (1)

Art. no. 67105

EN

This study presents the development and validation of a high-resolution 3D hydrodynamic model, CEMBS-PolSea, designed to resolve submesoscale features in Polish Marine Areas. The model, derived from the Community Earth System Model (CESM), employs a horizontal resolution of 575 m and 66 vertical layers. It incorporates advanced parameterizations for horizontal and vertical mixing processes, and integrates meteorological and river inflow data. A novel satellite data assimilation module was implemented to enhance model accuracy. The model was calibrated and validated using in situ measurements from the International Council for the Exploration of the Sea (ICES) database and satellite observations over the period 2019–2023. Results demonstrate strong agreement between model outputs and observational data, particularly for surface temperature (Pearson’s r = 0.95) and salinity (r = 0.89). The model successfully captures temporal and spatial variations in temperature and salinity profiles, with some discrepancies noted in deeper layers. The integration of satellite data assimilation significantly improved model performance, particularly in surface temperature predictions. This high-resolution model represents a significant advancement in simulating complex coastal dynamics and submesoscale features in the Polish Marine Areas, offering a valuable tool for marine ecosystem management and climate change impact studies in the region.

7

Modelowanie numeryczne przepływu stali w krystalizatorze podczas odlewania ciągłego wlewków długich

Cwudziński Adam, Mędrecki Marcin

Hutnik, Wiadomości Hutnicze

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2025

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Vol. 92, nr 2

19--23

PL

Krystalizator jest jednym z urządzeń, przez które przepływa ciekła stal podczas procesu ciągłego odlewania i które pełni ważną rolę w kontroli procesu krzepnięcia. Przeprowadzone symulacje komputerowe miały na celu analizę wpływu prędkości odlewania na hydrodynamikę ciekłej stali w krystalizatorze. W badaniach zwrócono uwagę na gradient prędkości ciekłej stali oraz obszar występowania strumieni wstecznych w przestrzeni krystalizatora. Określono również wpływ prędkości odlewania na naprężenia styczne powstające w wyniku interakcji ciekłej stali z krzepnącym wlewkiem.

EN

Mould is the one of the device of the continuous casting process, during the liquid steel flows through it, and it plays an important role of solidification control. Aim of the conducted computer simulations was to analyze influence of the casting speed on liquid steel hydrodynamics in the mould. In the investigations liquid steel velocity gradient and backflow zone occurring in the working space of the mould were paid attention. The influence of the casting speed on the shear stress creating by liquid steel interaction with billets shell was also determined.

8

Specific aspects of hydrodynamic cavitation in water treatment. An overview

Viktor Voroshchuk, Kravets Oleh, Drozdziel Pawel, Rudawska Anna

Economics and Environment

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2025

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No. 4

art. no. 1363

EN

This paper reviews the development and applications of hydrodynamic cavitation in water treatment, with a particular emphasis on the removal of organic and microbiological contaminants. A comparative analysis of published studies is conducted to evaluate the performance of various cavitation configurations, including Venturi tubes, diaphragm systems, and rotor-stator devices. The findings show that hydrodynamic cavitation combines mechanical, thermal, and radical mechanisms that enable the degradation of dyes, pharmaceutical residues, and persistent organic pollutants, as well as the inactivation of pathogenic microorganisms. The analysis identifies cavitation number, flow velocity, pressure drop, and physicochemical properties of the medium as key factors influencing process efficiency. Practical implications include reduced chemical demand and lower energy consumption compared with conventional disinfection methods. The review highlights the potential of hybrid systems (HC+H2O2, HC+O3, HC+TiO3/UV), which often achieve over 90% COD and TOC removal, and indicates directions for optimisation and scale-up of cavitation reactors.

PL

Celem artykułu jest przedstawienie aktualnego stanu wiedzy na temat zastosowań kawitacji hydrodynamicznej w oczyszczaniu wody oraz identyfikacja kluczowych uwarunkowań procesowych. Zastosowano metodę systematycznego przeglądu literatury obejmującą badania z lat 2015-2025. Analiza uwzględnia mechanizmy działania kawitacji, parametry hydrodynamiczne, właściwości fizykochemiczne cieczy oraz efektywność różnych konfiguracji urządzeń. Szczególna uwaga poświęcona jest hybrydowym rozwiązaniom (HC+H2O2, HC+O3, HC+TiO3/UV), które osiągają ponad 90% redukcji zanieczyszczeń organicznych (COD i TOC). Przedstawiono także ograniczenia wynikające z różnorodności geometrii reaktorów, braku standaryzacji parametrów oraz niewystarczającej liczby badań pilotowych. Wartością dodaną pracy jest systematyzacja czynników wpływających na skuteczność kawitacji oraz wskazanie kierunków dalszych badań istotnych dla praktycznej implementacji technologii.

9

A simplified computational approach to hydrodynamic behaviour of an ammonia-phosphoric acid mixing system within a tubular reactor

Murasiewicz Halina, Zakrzewska Barbara

Chemical and Process Engineering : New Frontiers

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2025

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Vol. 46, nr 4

art. no. e107

EN

This study employs a simplified computational approach to investigate the hydrodynamic behaviour within tubular reactors for Monoammonium Phosphate (MAP) fertilizer production. The main objective is to understand the impact of key parameters, including volumetric flow rates, fluid properties, reactor geometry, operating conditions, and distinct inlet configurations, on reactant distribution and mixing efficiency. Two primary cases were investigated: Case 1, where ammonia was injected coaxially with phosphoric acid introduced via a side inlet; and Case 2, where phosphoric acid was injected coaxially with ammonia entering through a side inlet. A significant effect of the reactant dosing location into the reactor was observed and was more effective in Case 2 with respect to the MAP formation reaction. High ammonia and acid velocities were obtained at the constriction (nozzle) in the reactor tube. The nozzle design caused a uniform discharge of the reactants to the further part of the reactor, where there was good mixing of the components, comparable to Cases 1 and 2. These simulations provide a practical tool for engineers to adjust design parameters, optimize residence times, and ensure consistent product quality, facilitating both laboratory and industrial-scale applications. Future studies should incorporate chemical species transport and reaction kinetics to further enhance model accuracy and provide a more comprehensive understanding of the reaction process. Ultimately, this research offers valuable insights for informed decision-making in optimizing tubular reactor design and operation, leading to improved MAP production efficiency and product quality.

10

Numerical prrediction of pneumatic Life raft performance

Jachowski J., Książkiewicz E.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2024

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Vol. 18 No. 1

229--232

EN

The success of the Search and Rescue (SAR) operation depends on the correct assignation of the search area for the drifting pneumatic life raft, with particular emphasis on leeway. The leeway is directly dependent on the hydrodynamic drag and wind pressure force acting on above-water and underwater parts of the life raft. The paper presents the numerical study on the pneumatic life raft performance including hydrodynamic and aerodynamic characteristics in a wide range of operational conditions. The numerical simulation results were compared with model test results obtained in towing tank and wind tunnel. The proper prediction of life raft performance is important for determination of life raft safety function dependent on wind velocity and operational characteristics. The results of numerical simulation are in line with data available in literature and obtained from empirical investigations.

11

Comparative assestment of the effect of changing the breadth (b) of the ship on the stability of the tugboat

Alamsyah A., Fikri M., Suardi Suardi, Pawara Muhammad Uswah, Ikhwani R.J., Setiawan Wira, Paroka D.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2024

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Vol. 18 No. 4

905--914

EN

This paper reviews the effect of changing the breadth of a tugboat before and after production on ship stability. The numerical simulation method (maxurf stability) is applied. Likewise, another approach uses the Benjamin Spence (integrator) method. The standard used is IMO. Several limits become parameters for assessing the increase and decrease in ship stability. Several ship load cases are simulated to produce righting arm curves. The construction of a tugboat with a length of 28 meters is the object of this research as a case study. We compared the righting arm curve from the Maxurf stability analysis with Benjamin Spence's analysis to confirm the accuracy of the calculation results. Both methods show a significant influence regarding changes in the breadth of the tugboat. The produced righting arm curve consistently shows changes in the stability and performance of the ship. There is a reduction in the area under the GZ curve. The IMO provides three of the five standards and recommendations regarding the area under the GZ curve. The reduction of the area under the GZ curve is 17~22% for the Benjamin Spence method and 12~18% for the Maxurf stability. This percentage applies to all load-case simulations. This research contributes to providing an understanding of the effect of changes in ship width on decreasing stability.

12

A note on model-as-usual for leeway and drift track in marine navigation

Aldea Nicoleta, Kopacz Piotr

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2024

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Vol. 18 No. 4

943--948

EN

In this note, we briefly discuss and compare the simplified models of the water current and wind effects on ship’s resultant track in marine navigation, which are represented by drift and leeway. Our focus is on a compensation of the lateral component of perturbation with respect to the ship heading line, which is included in the equations of resultant motion. The variable magnitude of the compensation affects ship navigation, in particular, total drift angle, speed and course over ground. The corresponding unit time fronts, speed changes and drift angle in relation to the various ranges of the cross compensation and own ship true course are also compared by some illustrative examples.

13

Comparative Study on the Microplastics Abundance and Characteristics in Marine Protected Area in Karimunjawa National Park, Indonesia

Widiaratih Rikha, Marganita Dia, Suryoputro Agus Anugroho Dwi, Handoyo Gentur, Maslukah Lilik, Satriadi Alfi, Satya Eridhani Dharma

Journal of Ecological Engineering

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2024

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Vol. 25, nr 4

119--130

EN

Microplastics (MPs) are discovered in various places even encroaching on marine protected areas (MPA). The aim of this research is to investigate the occurrences of MPs pollutant in MPA and non-MPA in Karimunjawa National Park (KNP). The results showed that MPs from sea surface water were higher in MPA than non-MPA with range as 47.89–106.20 items/L, dominated by fragment, 1–50 µm size, black color and HDPE, LDPE, PP, Nylon, PVC, ABS, and PET in polymer types. It induced since it supplied from it surrounding, specifically the south of MPA, whereas there have been cottage constructions generating many marine debris. These findings indicate that occurrence of MPs still dominantly influenced from anthropogenic activity. However, the hydrodynamic and MPs characteristic as well play an important role in MPs distributions.

14

Development and validation of an operational fast time ship manoeuvring solver to increase navigation efficiency in horizontally restricted waterways

Kazerooni M. F., Rahimian M., Tree M., Womersley T., Jensen B.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

71--76

EN

Growth of demand for containerized cargo shipping has put more ports into pressure to accommodate larger vessels. Considering the limitations on dimensions of navigation channels, this is not feasible unless aiming for significant capital dredging or alternatively creating high precision predictions of vessel motions subjected to environmental forcing and interaction with shallow and restricted waterway. NCOS ONLINE (Nonlinear Channel Optimisation Simulator) is a state of the art navigation support tool which combines DHI’s high level forecast of environmental conditions with mathematical model of ship motions to add an extra level of accuracy in predicting the under-keel clearance and vessel swept path to boost the efficiency of navigation and pilotage within restricted channels. NCOS Manoeuvring Module utilizes an autopilot scheme based on PID (Proportional / Integral / Derivative) controller and Line of Sight Algorithm to FORCE Technology’s SimFlex4 manoeuvring solver for prediction of manoeuvring ship swept path and response, which will effectively bring the accuracy of real time full bridge simulator to fast time operation support tool. In this paper, the result of mathematical model is validated against fullscale measurements of containership transits through Port of Auckland Navigation channel by comparing pilot commands, leeway drift and swept path through output of portable pilotage unit. According to the results the model is found promising to predict the behaviour of human pilots with precision required in operational use. Finally, the swept path and manoeuvring performance of a sample transit is assessed on different environmental conditions and tide stages to evaluate the safe transit windows in operation.

15

Flotation of copper-bearing shale at different pH values of solutions and sodium chloride concentrations

Sajewicz Jakub, Ratajczak Tomasz

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 6

art. no. 176242

EN

Flotation of copper-bearing shale in aqueous solutions of NaCl at their different pH values was investigated. The tests were carried out in a laboratory flotation machine. The pH range was between 5 and 10 while NaCl concentrations were 0.5M, 1.0M and 2.0M. It was observed that the flotation recovery of the copper shale was increasing with the increase of pH and concentration of the salt solution. On the basis of thermodynamic and hydrodynamic considerations it was postulated that the increasing surface tension was responsible for better shale flotation observed with increasing salt concentration. The observed improved shale flotation caused by increasing pH is most likely due to changes in the properties of the thin film between particle and bubble including mosaic structure of water on the surface of shale. It was shown that the zeta potential of shale particles, zeta potential of air bubbles, solution surface tension, and shale hydrophobicity were not responsible for the increasing with pH recoveries.

16

Control of capillary instability under hydrodynamic impact on the reservoir

Panahov Geylani M., Abbasov Eldar M., Sultanov Babek N.

Nafta-Gaz

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2023

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R. 79, nr 2

71--83

EN

The paper presents the results of studies on optimisation of water impact on a reservoir by means of sequential periodic increase in hydrodynamic pressure in order to extract capillary trapped oil. The method provides a coordinated account of both displacement conditions and capacitive-filtration characteristics of fluid-saturated reservoirs. The results of experimental, theoretical and field studies of mass transfer processes in the presence of hydrodynamic nonequilibrium in heterogeneous porous media are presented. This paper considers a case where capillary forces are the determining factor for the displacement of immiscible liquids. Laboratory test results have shown that the formation of CO2 in the reaction of an alkaline solution with naphthenic components can make an additional contribution to the control of surface tension in porous media. A series of experimental studies were carried out on a core sample model to simulate the oil displacement by in-situ generated CO2 gas-liquid system. The article offers an analytical and technological solution to the problem of ensuring the value of “capillary number” and capillary penetration corresponding to the most complete extraction of trapped oil by regulating the “rate” of filtration (hydrodynamic injection pressure). The paper presents the field cases of implementing the new reservoir stimulation techniques to increase sweep efficiency. For effective residual oil recovery in fluid flow direction, conditions of stepwise (staged) maintenance of specified hydrodynamic water pressure at the boundary of injection contour are considered. Estimated calculations allow to determine time duration and stage-by-stage control of injection pressure as a requirement for reaching the expected increase in oil recovery.

PL

W artykule przedstawiono wyniki badań nad optymalizacją oddziaływania wody na złoże poprzez sekwencyjne, okresowe zwiększanie ciśnienia hydrodynamicznego w celu wydobycia kapilarnie zatrzymanej ropy. Metoda ta pozwala w sposób skoordynowany uwzględnić zarówno warunki wyporu, jak i charakterystykę kapilarno-filtracyjną złóż nasyconych cieczą. Przedstawiono wyniki badań doświadczalnych, teoretycznych i praktycznych procesów przenoszenia masy w obecności braku równowagi hydrodynamicznej w heterogenicznych ośrodkach porowatych. W artykule rozpatrywany jest przypadek, w którym siły kapilarne są czynnikiem decydującym o wypieraniu niemieszalnych cieczy. Wyniki badań laboratoryjnych wykazały, że powstawanie CO2 w reakcji roztworu zasadowego ze składnikami naftenowymi może mieć dodatkowy udział w kontroli napięcia powierzchniowego w ośrodkach porowatych. Przeprowadzono serię badań eksperymentalnych na modelu próbki rdzeniowej w celu symulacji wypierania ropy przez generowany in-situ układ gazowo-cieczowy CO2. W artykule zaproponowano analityczne i technologiczne rozwiązanie problemu zapewnienia wartości „liczby kapilarnej” i przenikania kapilarnego odpowiadających najbardziej pełnemu wydobyciu zatrzymanej ropy, poprzez regulację „szybkości” filtracji (ciśnienia zatłaczania hydrodynamicznego). W artykule przedstawiono przykłady praktycznego zastosowania nowych technik stymulacji złoża w celu zwiększenia efektywności wydobycia. W celu osiągnięcia efektywnego wydobycia ropy resztkowej w kierunku przepływu cieczy rozważono warunki stopniowego (podzielonego na etapy) utrzymywania określonego ciśnienia hydrodynamicznego wody na granicy konturu zatłaczania. Przeprowadzone obliczenia szacunkowe pozwalają na określenie czasu trwania i etapowego kontrolowania ciśnienia zatłaczania jako warunku osiągnięcia oczekiwanego wzrostu odzysku ropy.

17

Improvement of baffle type Rotating Packed Bed’s packing by visual study

Zawadzki Dawid, Majdzik Małgorzata, Hájek Ondrej, Malý Milan, Blatkiewicz Michał

Chemical and Process Engineering : New Frontiers

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2023

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Vol. 44, nr 3

art. no. e28

EN

Process intensification is one of the key branches of process engineering. High gravity equipment achieves intensification by substituting gravity with much higher centrifugal force. Rotating Packed Bed is the leading example of high gravity solutions, strongly facilitating gas-liquid mass transfer. However, cylindrical packings come with certain drawbacks, such as dry spots, that can be overcome with new solutions, such as baffle-based packing geometries. However, when baffles are arranged too close to each other, liquid bridges are formed between them, which may lead to decrease in mass transfer efficiency. This work is concerned with improvement of a Zickzack-like internal by the means of visual studies with the use of high-speed camera. According to measured ligament break-up length, two new packings were designed for particular rotational speeds and tested experimentally for effective mass transfer area and wet pressure drop.

18

A review of the state of research on bridge pier scour under combined action of waves and current

Kumar Lalit, Afzal Mohammad Saud

Acta Geophysica

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2023

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Vol. 71, no. 5

2359--2379

EN

This article presents a review of the state of research on bridge pier scour under combined wave–current flow. The hydrodynamics and scour around the bridge pier under combined wave–current flow have been explained in detail based on the information available in the literature. The impact of relative flow velocity (Ucw), Keulegan–Carpenter number (KC), absolute Reynolds number (Rea), and sediment characteristics on bridge pier scour under combined wave–current flow is presented. This study includes physical modelling of scour with various formulations to predict scour depth and calculation procedures related to scour under combined wave–current flow in the coastal environment. In addition, this study also provides the development of numerical models to investigate bridge pier scour in detail. In the end, future prospects of hydrodynamics and scour around the bridge pier under combined wave–current flow are delineated.

19

Rutile to tourmaline index – a tool for the recognition of the hydrodynamics of the depositional environment; a case study from the Campanian Szozdy Delta System, SE Poland

Cyglicki Michał, Remin Zbigniew

Acta Geologica Polonica

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2023

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Vol. 73, no. 4

833--851

EN

The newly discovered mid-Campanian Szozdy Delta System (Roztocze Hills, SE Poland) located in the south-ern part of the Polish Cretaceous Basin, at the northern edge of the Łysogóry-Dobrogea Land, has revealed in-teresting features concerning the relationship between the abundance of rutile and tourmaline. A distinct inverse relationship between rutile and tourmaline can be readily recognised in the succeeding units of the tripartite cyclothems (calcareous mudstone, calcareous sandstone, and calcareous gaize) representing the submarine part of the Szozdy Delta System. In the Szozdy section, both minerals are of similar shape (highly rounded), dura-bility, and size; they are, however, characterised by markedly different densities. Therefore, it might be expected that these two mineral phases will be strongly dependent, both vertically and spatially, on the local energy of the sedimentary environment hydrodynamic power that existed during the deposition of the succeeding units of the cyclothems. The lighter tourmaline was likely transported further to the more quiescent prodelta environment, rendering the prodelta facies overrepresented in this mineral, whereas the heavier rutile was deposited closer to the river discharge. Such relative change in the abundance of these two mineral phases, emphasised by a standardised Z-score statistics, is referred here to as rutile to tourmaline index (RuTidx). Accordingly, as the RuTidx increases, the hydrodynamic power in the sedimentary environment increases as well. Since these two mineral phases are comparatively immune to alteration during the sedimentary cycle, the RuTidx is considered here to be an independent tool in recognising the hydrodynamics of the depositional environments of any age.

20

Simulation study of hydrodynamic cavitation in the orifice flow

Pietrykowski Konrad, Karpiński Paweł

Applied Computer Science

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2022

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Vol. 18, no. 3

31--41

EN

Hydrodynamic cavitation is a phenomenon that can be used in the water treatment process. For this purpose, venturis or orifices varying in geometry are used. Studying this phenomenon under experimental conditions is challenging due to its high dynamics and difficulties in measuring and observing the phase transition of the liquid. For this reason, the CFD method was used to study the phenomenon of hydrodynamic cavitation occurring in water flow through the orifice and then analyze flow parameters for different boundary conditions. The research was performed for four different orifice geometries and two defined fluid pressure values at the inlet, based on a computational 2D model of the research object created in Ansys Fluent software. As a result of the numerical simulation, the distribution of fluid velocity and pressure and volume fraction of the gas phase were obtained. A qualitative and quantitative analysis of the phenomenon of hydrodynamic cavitation under the considered flow conditions was conducted for the defined orifice geometries. The largest cavitation zone and thus the largest volume fraction of the gas phase was obtained for the orifice diameter of 2 mm with a sharp increase in diameter. However, the geometry with a linear change in diameter provided the largest volume fraction of the gas phase per power unit.