Staff publications (AEPe)

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  • Item type: Item , Access status: Open Access ,
    Comparison of laboratory-scale methods for assessing deposit-induced corrosion of boiler materials in biomass combustion and recovery boilers
    (Springer, 2025-08-01) Eriksson, Jan-Erik; Mori, Stefano; Silvander, Linus; Hupa, Leena; Lehmusto, Juho
    Various instrumental methods for analyzing high-temperature corrosion of boiler materials were explored and compared. These methods were applied to gain deeper insights into corrosion due to two salt mixtures containing Na, K, SO4, and Cl below and above the mixtures’ first melting points. Stainless steel AISI316 and high-alloyed Sanicro28, typically used in heat exchangers in power plants, were exposed to salt mixtures in a laboratory tube furnace for 168 h. The extent of the metal corrosion following exposure was measured through mass loss, changes in the surface topography using optical 3D imaging, and dimensional metrology. Additionally, the morphology, thickness, and composition of the formed oxide scales were characterized using SEM–EDX. The information gathered from each method confirmed the impact of the synthetic salt deposit and temperature on the metal corrosion. Combining several methods enables detailed studies of changes taking place on the metal surface after exposure to challenging environments. The results also suggested that partial melting of the deposit had a higher impact on the corrosion than its chloride content.
  • Item type: Item , Access status: Open Access ,
    Toward intuitive drift assist control: driver drift intention recognition using a data-based approach
    (Taylor and Francis, 2025) Sun, Yiwen; Velenis, Efstathios; Krishnakumar, Ajinkya
    In contrast to autonomous drifting where path-planning determines when and where the vehicle drifts, to support drift-assist control systems in the framework of Advanced Driving Assistance System (ADAS), the human driver’s intention needs to be recognised before the system intervenes with its assist functionality to facilitate drifting at the desired moment. We propose a method based on Bidirectional Long Short-Term Memory Network (Bi-LSTM) to interpret driver’s intention to start/exit drifting, utilising only basic driver inputs and vehicle state signals. Firstly, to comprehensively understand driver’s behaviour during drifting, we discuss the distinctive features in throttle and steering inputs and the corresponding vehicle acceleration signals during drift cornering and normal cornering, respectively. Next, two Bi-LSTM models are designed separately for the recognition of the ‘Intention to Start Drifting’ and the ‘Intention to Exit Drifting’. Then, these models are trained and evaluated through a data set that contains over 500 laps of driving collected from the racing simulator Assetto Corsa. To validate the proposed approach, test sets of different drivers, track layouts and car models are adopted. The proposed intention recognition models successfully reach an accuracy of over 90% in recognising the two concerned intentions and outperform other classification methods in comparison.
  • Item type: Item , Access status: Open Access ,
    An optimization-driven design framework for inertance-integrated hydraulic shock absorbers: incorporating nonlinear and parasitic effects
    (Springer, 2025-12-31) He, Haonan; Wang, Zixiao; Li, Yiyuan; Song, Zhiguang
    Integrated spring-damper-inerter systems have been shown to outperform traditional damper-only absorbers in suppressing mechanical vibrations, driving interest in incorporating hydraulic stiffness, damping, and inertance components into automotive shock absorbers to enhance ride comfort. Extensive research has been conducted to identify the optimal absorber configuration from a vast design space. However, existing design approaches often neglect the nonlinear and parasitic effects (NPEs) inherent in hydraulic components and consider only limited topological layouts, thereby limiting the comprehensiveness and accuracy of the design space exploration. This oversight can result in discrepancies between simulated and real-world performance, potentially leading to suboptimal designs. To address this, a novel computer-aided engineering (CAE) framework is proposed for optimizing the configuration of inertance-integrated hydraulic shock absorbers. The framework follows a three-step process: (i) a graph-based method for enumerating all feasible hydraulic network layouts from a predefined catalog of components, (ii) an automated MATLAB subroutine for modeling these networks in Simscape, incorporating component models that explicitly account for NPEs, and (iii) a MATLAB-CarMaker co-simulation workflow for optimizing the hydraulic networks within a high-fidelity vehicle model. A case study involving a saloon car subjected to an ISO 8608 rough road input demonstrates the effectiveness of the framework. The optimized absorber design improves ride comfort by 17.6% when the NPE associated with hydraulic inertance realization is neglected and by 8.3% when it is considered, both while meeting dynamic tire load and suspension travel constraints. These results emphasize the importance of incorporating NPEs in the design process and validate the framework as an effective CAE tool for developing high-performance hydraulic absorbers for practical applications.
  • Item type: Item , Access status: Open Access ,
    Fast implicit direct-forcing immersed boundary method (FIDF-IBM)
    (Elsevier, 2025-10) Farah, Elias; Ouahsine, Abdellatif; Verdin, Patrick G.
    A fast implicit direct-forcing immersed boundary method (FIDF-IBM) is introduced for the simulation of incompressible flows over arbitrarily moving solid structures. This method leverages the operator splitting approach of the pressure implicit with splitting of operators (PISO) algorithm to decouple the pressure, velocity, and boundary force in the solution process. This maintains the no-slip/no-penetration (ns/np) boundary constraint and enforces the divergence-free condition in a segregated manner in the solid and fluid domains, respectively. The proposed scheme produces a modified pressure Poisson equation (PPE) that includes the boundary force already satisfying the ns/np boundary constraint, allowing the usage of fast iterative PPE solvers. The term “fast direct-forcing” is achieved by coupling Lagrangian weight methods that enhance the reciprocity of the IBM-related linear operators with the IBM implicit formulation. Additionally, an appropriate boundary force inheritance from previous time-steps further boosts the performance of the implicit DF-IBM algorithm. The method’s efficiency and capability are verified through different stationary and moving immersed boundary benchmark tests.
  • Item type: Item , Access status: Open Access ,
    Techno-economic assessment of pressure swing adsorption tail gas decarbonisation for blue hydrogen production
    (Elsevier, 2025-10) Golmakani, Ayub; Khallaghi, Navid; Amiri, Amirpiran; Manovic, Vasilije; Nabavi, Seyed Ali
    Steam methane reforming (SMR) is a leading technology for hydrogen production. However, this technology is still carbon-intensive since, in current SMR units, the PSA tail gas containing H2, CO, and CH4 is burned at the reformer with air and exits the stack at a CO2 purity of less than 5%, which is not feasible to capture. In this paper, we aim to either harness the energy content of this gas to generate power in a solid oxide fuel cell (SOFC) or burn it via chemical looping combustion (CLC) or oxy-combustion process to produce off-gas with high CO2 purity ready to storage. Therefore, an industrial-scale PSA with 72,000 Nm3/h feed capacity was modelled to obtain the tail gas flow rate and composition. Then, CLC, SOFC, and oxy-combustion were modelled to use tail gas. Finally, a techno-economic analysis was conducted to calculate each technology's levelised cost of hydrogen (LCOH). It was observed that CO2 purity for CLC meets the criteria for storage (>95%) without further purification. On the other hand, from the economic point of view, all three technologies show a promising performance with an LCOH of 1.9 €/kg.
  • Item type: Item , Access status: Open Access ,
    Strain based finite fracture mechanics for fatigue life prediction of additively manufactured samples
    (Springer, 2025-08) Mirzaei, Amir M.; Mirzaei, A. H.; Sapora, A.; Cornetti, P.
    A novel failure criterion, named Strain-based Finite Fracture Mechanics, is proposed to predict the fatigue life of additively manufactured notched components under uniaxial loading conditions. The model relies on the simultaneous fulfillment of two conditions: a non-local strain requirement and the discrete energy balance. The inputs of the model are strain and the stress intensity factor at failure, which depend on the number of cycles according to power law equations. The inputs can be obtained based on strain-life and stress intensity factor-life data from plain and notched specimens. The present approach is comprehensively validated against experimental datasets on additively manufactured samples from the literature for different materials, raster angles, notch geometries and loading conditions. Predictions by other approaches, such as Finite Fracture Mechanics (in its original stress formulation) and the Theory of Critical Distances, are also considered, for the sake of completeness. Results show that, in general, the proposed strain-based model is more accurate and provides consistently precise predictions across different cases.
  • Item type: Item , Access status: Open Access ,
    Effects of Reynolds number and layout on aerodynamic and heat transfer characteristics of an aluminum sheet treated in a gas-cushion furnace
    (Elsevier, 2025-08-01) Wu, Licheng; Kang, Can; Verdin, Patrick G.; Yin, Jin; Xie, Yu
    Heat treatment of an aluminum sheet through a gas-cushion furnace is numerically investigated. The sheet of 0.6 mm thick was suspended due to simultaneous impingement of upward and downward gas jets. Effects of Reynolds number (Re = 8,000–32,000) and upper/lower distance ratio (du/dl = 3:5, 1:1, 5:3) on flow and heat transfer characteristics were investigated, along with the structural characteristics of the sheet. The validation of the numerical results was implemented though experimental data. The results indicate that an increase in Re leads to an increase in circulating flow intensity in the gas-cushion furnace, due to an increase in the peak value of Nusselt number (Nu). However, the variation of Re imposes an insignificant effect on the pressure coefficient distribution over the sheet. At Re = 24,000, an upward deformation is evidenced at the middle part of the sheet. As Re decreases to 16,000, relatively slight downward deformation appears at the middle part of the sheet. At an upper/lower distance ratio of 3:5, a uniform pressure distribution is obtained at the lower surface of the sheet. Furthermore, the near-wall flow in the middle part of the sheet brings benefits, and such a layout is responsible for high average temperature of the sheet.
  • Item type: Item , Access status: Open Access ,
    Stress, strain, or displacement? A novel machine learning based framework to predict mixed mode I/II fracture load and initiation angle
    (Elsevier, 2025-08-25) Mirzaei, Amir M.
    Accurate prediction of fracture load and initiation angle under complex loading conditions, like mixed mode I/II, is essential for reliable failure assessment. This paper aims to develop a machine learning framework for predicting fracture load and crack initiation angles by directly utilizing stress, strain, or displacement distributions represented by selected nodes as input features. Validation is conducted using experimental data across various mode mixities and specimen geometries for brittle materials. Among stress, strain, and displacement fields, it is shown that the stress-based features, when paired with Multilayer Perceptron models, achieve high predictive accuracy with R2 scores exceeding 0.86 for fracture load predictions and 0.94 for angle predictions. A comparison with the Theory of Critical Distances (Generalized Maximum Tangential Stress) demonstrates the high accuracy of the framework. Furthermore, the impact of input parameter selections is studied, and it is demonstrated that advanced feature selection algorithms enable the framework to handle different ranges and densities of the representing field. The framework’s performance was further validated for datasets with a limited number of data points and restricted mode mixities, where it maintained high accuracy. The proposed framework is computationally efficient and practical, and it operates without any supplementary post-processing steps, such as stress intensity factor calculations.
  • Item type: Item , Access status: Open Access ,
    Engineering aqueous electrolytes with vicinal s‐based organic additives for highly reversible zinc‐ion batteries
    (Wiley, 2025-05-19) Li, Teng; Naveed, Ahmad; Zheng, Jiongzhi; Chen, Bixian; Jiang, Mingfeng; Liu, Biyuan; Zhou, Yu; Li, Xiaowei; Su, Mingru; Guo, Ruiqiang; Sumner, Joy; Li, Cheng Chao; Liu, Yunjian
    The commercial deployment of aqueous zinc‐ion batteries (AZIBs) is hampered by dendrites, the hydrogen evolution reaction (HER), and corrosion reactions. To tackle these challenges, we have introduced 3,3′‐dithiobis‐1‐propanesulfonic acid disodium salt (SPS), a symmetrical sulfur‐based organic salt, as an electrolyte additive for AZIBs. Unlike conventional electrolyte additives that favor (002) deposition, SPS enables dense (100) growth through a unique symmetrically aligned concentration‐controlled adsorption network, affording structural uniformity and compactness to the Zn deposit layer. The dual‐action symmetrical SPS additive adsorbs onto the Zn surface via vicinal sulfur atoms, blocking electrolyte access to the Zn anode, enhancing the transportation kinetics of Zn2+, and simultaneously promoting desolvation by displacing water molecules from the solvation shell. This synergistic effect improves the stability of the Zn anode by mitigating HER and corrosion, resulting in over 1100 h of cycling at 5 mA cm−2, 5 mAh cm−2, stable operation at even 15 mA cm−2, 15 mAh cm−2, and achieving impressive Coulombic efficiency (CE) of 99.41%. As validation, the Zn/NaV3O8·1.35H2O cell with SPS‐additive afforded high cycling stabilization and excellent capacity retention of 95.5%. This study offers valuable insights for advancing AZIBs and other metal‐based batteries.
  • Item type: Item , Access status: Open Access ,
    Navigating barriers to decarbonisation of UK’s aviation sector through green hydrogen: a multi-scale perspective
    (MDPI, 2025-06-20) Mirzania, Pegah; Balta-Ozkan, Nazmiye; Rothe, Henrik; Gratton, Guy
    Aviation is widely recognised as one of the most carbon-intensive modes of transport and among the most challenging sectors to decarbonise. The use of green hydrogen (H2) in airside operations can help reduce emissions from air transport. While the pace and scalability of technology development, including H2-powered and ground support equipment, will be key factors, other financial, regulatory, legal, organisational, behavioural, and societal issues must also be considered. This paper investigates the key opportunities and challenges of using H2 in the aviation industry through eleven semi-structured interviews and a virtual expert workshop (N = 37) with key aviation industry stakeholders and academia. The results indicate that, currently, decarbonisation of the aviation sector faces several challenges, including socio-technical, techno-economic, and socio-political challenges, with socio-technical challenges being the most prominent barrier. This study shows that decarbonisation will not occur until the UK government is ready to have all the required infrastructure and capacity in place. Governments can play a significant role in directing the necessary ‘push’ and ‘pull’ to develop and promote zero-carbon emission aircraft in the marketplace and ensure safe implementation.
  • Item type: Item , Access status: Open Access ,
    Coupled hydro-aero-turbo dynamics of liquid-tank system for wave energy harvesting: numerical modellings and scaled prototype tests
    (Elsevier, 2025-09) Zhang, Chongwei; Zhu, Xunhao; Zhang, Cheng; Huang, Luofeng; Ning, Dezhi
    The wave-energy-harvesting (WEH) liquid tank with an air-turbine system has distinct advantages in survivability and durability. Its air-turbine effects have long been simplified using orifices, perforated plates, or empirical formulae. This study proposes an integrated numerical model to couple with actual turbine motions. A series of experiments are conducted on a scaled prototype of the WEH liquid tank with an impulse air turbine system. Benchmark experimental data are obtained for validation of the numerical model. The proposed integrated numerical model accurately reproduces the experimental observations. The effects of turbine parameters on the coupled hydro-aero-turbo behavior are systematically investigated. The optimal power take-off damping for the WEH liquid tank is identified. A multi-layered impulse air turbine system (MLATS) is creatively introduced into the liquid-tank system to explore its capability in improving efficiency and reliability. Compared to the single-rotor case, the MLATS with three rotors can increase the averaged power output of the WEH liquid tank by up to 40%. Through a series of failure tests, a three-rotor turbine shows greater reliability than a conventional single-rotor turbine.
  • Item type: Item , Access status: Open Access ,
    Life cycle analysis of ammonia-driven calcium looping processes for post-combustion CO2 capture in NGCC power plants
    (Elsevier, 2025-08) Zheng, Yawen; He, Song; Liu, Jianhui; Wang, Junyao; Zhu, Mingming; Yang, Guang; Wang, Wenxiang
    Integrating calcium looping (CaL) based carbon capture and storage (CCS) technology with an existing natural gas combined cycle (NGCC) power plants offers a promising solution for low-carbon energy production. This work introduces a novel NH3-driven CaL process for retrofitting NGCC plants. The economic performance and environmental impacts of the process were analyzed through life cycle analysis and compared with those of conventional oxy-fuel CaL and solar-driven CaL technologies. Results indicate that, the NH3-driven CaL demonstrates with a very low energy penalty of only 2.6 points, while the solar-driven CaL method faces a 14-points energy penalty. From an environmental perspective, the NH3-driven CaL method, with considering various ammonia sources, significantly impacts the environment more than oxy-fuel and solar-driven methods, with global warming potential values of 207.7 (oxy-fuel), 170.7 (solar), and 197.6–258.8 g CO2-eq/kWh (green NH3). Economically, based on an annual operation time of 4000 h of NGCC, the solar-driven CaL system has the lowest Life Cycle Cost of GHG Removed (LCOR) at 247.7 $/t CO2. With anticipated reductions in ammonia prices to 240 $/t in 2050, the NH3-driven CaL system is expected to gain a significant advantage in economic at 46.5 $/t CO2 when natural gas price is 0.6 $/Nm3. And it is important to pay attention the clean production process of ammonia to reduce its impact on the environment.
  • Item type: Item , Access status: Open Access ,
    A first-of-its-kind two-stage dew-point evaporative cooler with high energy efficiency and compact design
    (Elsevier, 2025-10-01) Chen, Zhang; Zhao, W. J.; Wang, B. C.; Huang, Luofeng; Ding, J. N.; Cheng, G. G.; Bui, D. T.
    This research addresses the long-standing high working air ratio problem of conventional single-stage dew-point evaporative coolers (DPECs) by developing a first-of-its-kind two-stage DPEC. The system introduces a novel indirect cooling mechanism that distributes the cooling load across two sequential stages, significantly reducing the product air required for evaporation and enhancing energy efficiency. The key component of the cooler is a compact heat and mass exchanger capable of handling four fluid flows within a single unit, ensuring high performance and space efficiency. Tested under subtropical climate conditions, the developed two-stage DPEC demonstrated exceptional performance, preserving 88–90 % of the product air while maintaining its temperature below the wet-bulb and near the dew point. Additionally, it achieved a coefficient of performance (COP) of 15–17 under actual operating conditions, far surpassing conventional air conditioning systems. These results highlight its superior cooling capacity, energy efficiency, and compactness compared to existing single-stage M–cycle DPECs. The two-stage DPEC, with its high efficiency and compact design, is a scalable and sustainable cooling solution for real-world heating, ventilation, and air conditioning (HVAC) systems, offering significant energy savings and improved thermal comfort. This study underscores its potential as a transformative technology for reducing energy consumption and addressing cooling demands in subtropical and tropical climates.
  • Item type: Item , Access status: Open Access ,
    Optimising vehicle performance with advanced active aerodynamic systems
    (Taylor and Francis, 2025-01-01) Rijns, Steven; Teschner, Tom-Robin; Blackburn, Kim; Siampis, Efstathios; Brighton, James
    This study investigates the performance potential of advanced active aerodynamic systems on high-performance vehicles. Static and active aerodynamic configurations, including asymmetrically actuated systems, are evaluated to identify performance gains and the mechanisms driving these improvements. Vehicle performance is optimised using a minimum lap time simulation framework, which utilises a transient vehicle dynamics model and CFD-derived aerodynamic data. Results indicate that configurations with greater aerodynamic adaptability enhance acceleration, braking, cornering, and straight-line performance, yielding notable lap time reductions compared to a static aerodynamic configuration. The asymmetrically controlled aerodynamic configuration achieves the highest lap time reduction of approximately 0.92 s (0.76%) due to its ability to modulate downforce both longitudinally and laterally. Optimal control strategies show that aerodynamic elements are actuated to balance vertical tyre load shifts resulting from load transfer, prioritising downforce on underloaded tyres in demanding scenarios like braking, cornering, and acceleration. Additionally, optimal design parameters for the brake, torque and roll stiffness distributions shift rearward as configurations provide greater control of aerodynamic loads on the rear axle. Overall, this research demonstrates the performance advantages of active aerodynamic systems and offers insights into the mechanisms underlying these enhancements, establishing a foundation for further innovations in the field.
  • Item type: Item , Access status: Open Access ,
    Hydrogen bond enhanced electrochemical hydrogenation of benzoic acid over a bimetallic catalyst
    (Royal Society of Chemistry (RSC), 2025-06-07) Catizane, Cesar; Jiang, Ying; Sumner, Joy
    Electrochemical hydrogenation (ECH) is a sustainable alternative to traditional hydrogenation methods, offering selective reduction of organic compounds under mild conditions. This study investigates the co-hydrogenation of benzoic acid (BA) and phenol on a platinum-ruthenium on activated carbon cloth (PtRu/ACC) catalyst, with a focus on the synergistic effects arising from hydrogen bonding. Density Functional Theory (DFT) calculations reveal that the formation of a hydrogen-bonded complex between BA and phenol facilitates adsorption energy and lowers activation barrier energies compared to BA alone. Experimental results demonstrate that a 20 mM BA and 5 mM phenol mixture achieves the highest conversion rate (87.33%) and faradaic efficiency (63%), significantly outperforming single-compound systems. Notably, co-hydrogenation facilitates the reduction of BA to cyclohexanemethanol, a valuable product for biofuel applications, which has reduced corrosiveness and improved energy density. These findings underscore the potential for optimising multi-compound ECH systems through targeted catalyst design and reagent concentration tuning, thus advancing the development of efficient strategies for bio-oil upgrading and sustainable chemical production.
  • Item type: Item , Access status: Open Access ,
    Unveiling host-guest interactions and stability of amine-functionalized silica sorbents for carbon capture
    (Elsevier, 2025-06-01) Ogunedo, Briggs M. O.; Wadi, Basil; Manovic, Vasilije; Nabavi, Seyed Ali
    Despite making significant progress in terms of capture kinetics and capacity, the thermochemical and cyclic instability of silica-based amine functionalized adsorbents present challenges for their practical implementation and economic viability. Accordingly, this work provides a critical review to analyse factors affecting thermal and cyclic stability of functional silica-based sorbents. The first section provides background information and context for the review. The second section focuses on the synthesis routes employed for silica-based amine functionalized adsorbents. The third section delves into the mechanism underlying the thermal and cyclic instability observed in these adsorbents. The fourth section explored the factors that influence the thermal and cyclic stability of silica-based amine functionalized adsorbents. The last section dissects host-guest interaction in silica-based amine functionalized adsorbents. The review concludes by underscoring the importance of further research and development into host-guest interaction studies in amine functionalized adsorbents to optimize performance and address the challenges associated with thermal and cyclic instability, thereby enhancing the practical feasibility of these adsorbents in carbon capture applications.
  • Item type: Item , Access status: Open Access ,
    Optimization of dual-module floating photovoltaic arrays: layout configuration and damping mechanisms for enhanced stability and energy performance
    (Elsevier, 2025-09-01) Zheng, Zhi; Hu, Jianjian; Huang, Qiang; Jin, Peng; Yang, Yifeng; Huang, Luofeng; Zhou, Zhaomin; Zhou, Binzhen
    Floating Photovoltaic (FPV) systems are a promising solution for offshore renewable energy, with modular FPV arrays offering significant potential for large-scale deployment. However, the development of FPV systems is hindered by insufficient understanding of their hydrodynamic performance, which affects stability and energy efficiency. This study proposes a dual-module FPV array combining box-type and semi-submersible modules to improve hydrodynamic stability under mild wave conditions in the South China Sea. The effects of array layout and PTO damping are examined under various wave conditions. The system is optimized to balance energy harvesting and motion control, and its performance is further evaluated under irregular waves at selected operational sites. Results indicate that the dual-module design effectively leverages the hydrodynamic characteristics of both module types, reducing motion responses and dynamic loads. The incorporation of optimal PTO damping further enhances system stability and energy efficiency by effectively suppressing pitch and heave motions, with maximum reductions of 31.43 % and 41.56 %, respectively, under the selected operational wave conditions. While damping remains effective under head-on waves, its performance slightly decreases under oblique waves, underscoring the importance of aligning the array with the predominant wave direction. Additionally, integrating a wave energy PTO system into the FPV array enables wave power to supplement solar energy, contributing 17.04 % of the total energy output at the selected operational sites. The proposed FPV system offers a practical solution for stabilizing floater motion, enhancing solar power generation, and capturing wave energy, advancing the feasibility of FPV technology for large-scale offshore applications.
  • Item type: Item , Access status: Open Access ,
    Hydrodynamic modeling of unstretched length variations in nonlinear catenary mooring systems for floating PV installations in small Indonesian Islands
    (MDPI, 2025-06-01) Jifaturrohman, Mohammad Izzuddin; Utama, I Ketut Aria Pria; Putranto, Teguh; Setyawan, Dony; Suastika, I Ketut; Sujiatanti, Septia Hardy; Satrio, Dendy; Hayati, Noorlaila; Huang, Luofeng
    Floating photovoltaic (FPV) systems offer a promising renewable energy solution, particularly for coastal waters. This preliminary numerical study proposes a single-array pentamaran configuration designed to maximize panel installation and enhance stability by reducing rolling motion. The study investigates the effect of mooring length on the motion behavior of FPV systems and actual line tension using the Boundary Element Method (BEM) in both frequency and time domains under irregular wave conditions. The results demonstrate that the mooring system significantly reduces all horizontal motion displacements, with reductions exceeding 90%. Even with a reduction of up to 51% in the unstretched mooring length, from the original design (304.53 m) to the shortest alternative (154.53 m), the motion response shows minimal change. This is supported by RMSE values of only 0.01 m/m for surge, 0.02 m/m for sway, and 0.09 deg/m for yaw. In the time-domain response, the shortened mooring line demonstrates improved motion performance. This improvement comes with the consequence of stronger nonlinearity in restoring forces and stiffness, resulting in higher peak tensions of up to 15.79 kN. Despite this increase, all configurations remain within the allowable tension limit of 30.69 kN, indicating that the FPV’s system satisfies safety criteria.
  • Item type: Item , Access status: Open Access ,
    Effect of the combined use of cryogenic + aging treatment on mechanical and damping property of Mn-Cu alloy based on response surface model
    (Elsevier, 2025-06-01) Ding, Ran; Liu, Guang-lei; Liu, Shu-cong; Ranjbar, Mostafa; Potter, Andrew; Liu, Hai-xia
    In this paper, the response surface method (RSM) is used to model the response surface between the target values and the cryogenic + aging treatment parameters. The effects of cryogenic + aging treatment on microstructures, mechanical, and damping properties of Mn-20Cu-5Ni-2Fe alloy are then investigated. The outcome indicates cryogenic + aging treatment can effectively enhance both mechanical and damping properties, and the optimum parameters cryogenic (-196 °C/30 h) + aging (428 °C/2 h) were obtained. The associated microstructural changes caused by the precipitated phase after the compound treatment resulted in an increase in the tensile strength from 358.3 MPa to 396.7 MPa, 38 MPa higher compared to that of the as-cast alloy. Meanwhile, it has the best damping property within a wide temperature range. At 50 °C, the internal friction value increased from 0.033 to 0.074, which was increased by 124 %. The damping strengthening mechanisms were discussed mainly from the perspective of the change in formation of {101} twins and motionable interface induced by fcc-fct transformation after the compound treatment. The obtained results provide a new reference for simultaneously improving mechanical and damping behaviors of Mn-Cu based alloys.
  • Item type: Item , Access status: Open Access ,
    A study of the motion response of floating solar PV and cross-flow savonius turbine in moored conditions
    (EDP Sciences, 2025-02-05) Ramsy de Fretes, Patrick; Jifaturrohman, Mohammad Izzuddin; Putranto, Teguh; Utama, I Ketut Aria Pria; Huang, Luofeng
    The transition towards Net Zero Emissions (NZEs) is being accelerated by hybrid renewable technologies such as Floating Photovoltaic (FPV) systems and marine current turbines, which combine solar panels and cross-flow marine turbines mounted on floating structures for near-shore applications. Despite their innovative potential, these renewable technologies face significant challenges in stability and durability due to the effects of wind, waves, and ocean currents. Therefore, a flexible mooring system is essential to address these challenges. This research examines the influence of variations in the number of mooring lines and wave direction on the hydrodynamic response of FPV systems. Utilizing a catenary mooring system consisting of anchors, mooring lines, floats, and connectors, the study evaluates various configurations to determine the optimal solution for enhanced motion stability. Computational Fluid Dynamics (CFD) simulations are employed to analyze the dynamic response of FPV systems under different environmental conditions, represented on a sea-state scale, with a focus on pure oscillatory motions: heave, roll, and pitch. The findings aim to provide valuable insights for the design and operation of more stable and efficient FPV systems in marine environments, thereby supporting the advancement of sustainable renewable energy.