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Pinto Ribeiro, A. (author), Ferreira, Carlos (author), Casalino, D. (author)With distributed propulsion and electric vertical take-off and landing aircraft on the rise, fast and accurate methods to simulate propeller slipstreams and their interaction with aircraft components are needed. In this work, we compare results obtained with a filament-based free wake panel method to experimental and previously validated...journal article 2024
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di Angelo, Monika (author), Durieux, T. (author), Ferreira, João F. (author), Salzer, Gernot (author)Blockchain programs (also known as smart contracts) manage valuable assets like cryptocurrencies and tokens, and implement protocols in domains like decentralized finance (DeFi) and supply-chain management. These types of applications require a high level of security that is hard to achieve due to the transparency of public blockchains....journal article 2024
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Ferreira, J.P. (author), Ferràs, David (author), Covas, Dídia I.C. (author), van der Werf, Job (author), Kapelan, Z. (author)The paper proposes a novel methodology to locate and quantify entrapped air pockets created during pipe-filling events often found in intermittent water supply systems. Different filling conditions were tested in an experimental pipe with a high point. Measurements were taken and video recordings were carried out to assess air pocket volumes...journal article 2024
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van der Hoek, D.C. (author), Van den Abbeele, B.H.L. (author), Ferreira, Carlos (author), van Wingerden, J.W. (author)Wind farm control can play a key role in reducing the negative impact of wakes on wind turbine power production. The helix approach is a recent innovation in the field of wind farm control, which employs individual blade pitch control to induce a helical velocity profile in a wind turbine wake. This forced meandering of the wake has turned...journal article 2024
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Giri Ajay, A. (author), Morgan, Laurence (author), Wu, Y. (author), Bretos, David (author), Cascales, Aurelio (author), Pires, Oscar (author), Ferreira, Carlos (author)This article presents a comparison study of different aerodynamic models for an X-shaped vertical-axis wind turbine and offers insight into the 3D aerodynamics of this rotor at fixed pitch offsets. The study compares six different numerical models: a double-multiple streamtube (DMS) model, a 2D actuator cylinder (2DAC) model, an inviscid free...journal article 2024
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Pasolari, R. (author), Ferreira, Carlos (author), van Zuijlen, A.H. (author), Baptista, C.F. (author)The past few decades have witnessed a growing popularity in Eulerian–Lagrangian solvers due to their significant potential for simulating aerodynamic flows, particularly in cases involving strong body–vortex interactions. In this hybrid approach, the two component solvers are mutually coupled in a two-way fashion. Initially, the Lagrangian...journal article 2024
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Yu, W. (author), Bajarūnas, Lukas K. (author), Zanon, Alessandro (author), Ferreira, Carlos J.S. (author)Vortex generators (VGs) have been widely applied to wind turbines thanks to their potential to increase aerodynamic performance. Due to the complex inflow perceived by a rotor and the proneness to flow separation, VGs on wind turbines usually experience highly unsteady flow. While there are models that exist to simulate the steady effects of...journal article 2024
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Pan, J. (author), Ferreira, Carlos (author), van Zuijlen, A.H. (author)To investigate the effect of force distributions of each turbine component on the power performance of the Darrieus–Savonius combined vertical axis wind turbine (hybrid VAWT), the hybrid VAWT is modeled as idealized turbine under various force distributions. The goal of idealization is to simplify the intricate interactions between the...journal article 2024
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Pasolari, R. (author), Ferreira, Carlos (author), van Zuijlen, A.H. (author)In the field of computational aerodynamics, it is vital to develop tools that can accurately, but also efficiently, simulate the flow around bluff objects and calculate the aerodynamic forces acting on them. When strong body–vortex interactions take place, the simulations become more demanding, since complex phenomena appear. To address this...journal article 2023
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Pinto Ribeiro, A. (author), Casalino, D. (author), Ferreira, Carlos (author)We investigate the aerodynamics of a surging, heaving, and yawing wind turbine with numerical simulations based on a free-wake panel method. We focus on the UNAFLOW (UNsteady Aerodynamics of FLOating Wind turbines) case: a surging wind turbine which was modeled experimentally and with various numerical methods. Good agreement with experimental...journal article 2023
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Pan, J. (author), Ferreira, Carlos (author), van Zuijlen, A.H. (author)To investigate power losses of a Darrieus-Savonius combined vertical axis wind turbine (hybrid VAWT) associated with the interaction between blades and wake, it is crucial to understand the flow phenomena around the turbine. This study presents a two-dimensional numerical analysis of vortex dynamics for a hybrid VAWT. The integration of a...journal article 2023
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Deng, Z. (author), Ferreira, Ana Lucia Morgado (author), Spanjers, H. (author), van Lier, J.B. (author)Bovine serum albumin (BSA) and casein (CAS) were used in batch tests to compare the protein degradation in the presence and absence of carbohydrates and volatile fatty acids (VFAs). The modified Gompertz model was applied to estimate reaction rates. The results showed that deamination was the rate-limiting step, with a rate ranging between 2...journal article 2023
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Bensason, D.Y. (author), Sciacchitano, A. (author), Ferreira, Carlos (author)In the present study, the near wake of a novel vertical-axis wind turbine known as the X-Rotor is experimentally investigated. Particle image velocimetry is used to measure the phase-locked flowfield at several streamwise locations within the rotor's volume of rotation. The results show a clear impact of coned blades on the streamwise and...journal article 2023
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Experimental and numerical study of the wake deflections of scaled vertical axis wind turbine modelsHuang, M. (author), Sciacchitano, A. (author), Ferreira, Carlos (author)Wake steering of vertical axis wind turbines (VAWTs) is investigated experimentally and numerically via stereoscopic particle image velocimetry and Reynolds averaged Navier-Stokes simulations. Three different blade pitch angles (-10°, 0°, 10°) of straight H-type VAWTs are adopted to deflect and deform the wake. The experimental results...journal article 2023
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Deng, Z. (author), Muñoz Sierra, Julian (author), Ferreira, Ana Lucia Morgado (author), Cerqueda Garcia, D. (author), Spanjers, H. (author), van Lier, J.B. (author)Treating protein-rich wastewater using cost-effective and simple-structured single-stage reactors presents several challenges. In this study, we applied an anaerobic sequencing batch reactor (AnSBR) to treat protein-rich wastewater from a slaughterhouse. We focused on identifying the key factors influencing the removal of chemical oxygen...journal article 2023
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Pinto Ribeiro, A. (author), Casalino, D. (author), Ferreira, Carlos (author)This paper presents low speed fluid structure interaction simulations of a highly flexible wing at various flow conditions, including flutter and excitation from sinusoidal gusts. Such wings are becoming more relevant in recent years, due to their potential for improving aerodynamics and reducing weight, while their flutter characteristics...journal article 2023
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Huang, M. (author), Vijaykumar Patil, Yugandhar (author), Sciacchitano, A. (author), Ferreira, Carlos (author)Wakes and wake interactions in wind turbine arrays diminish energy output and raise the risk of structural fatigue; hence, comprehending the features of rotor–wake interactions is of practical relevance. Previous studies suggest that vertical axis wind turbines (VAWTs) can facilitate a quicker wake recovery. This study experimentally...journal article 2023
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Lourenço, Miguel Sério (author), Fernández Ruiz, Miguel (author), Blaauwendraad, J. (author), Bousias, Stathis (author), Hoang, Linh Cao (author), Mata-Falcón, Jaime (author), Meléndez, Carlos (author), Mihaylov, Boyan I. (author), Ferreira, Miguel Pedrosa (author)The introduction of strut-and-tie models in fib Model Code 1990 as a design basis for discontinuity regions constituted a significant step toward promoting consistent design methods for reinforced concrete structures. In fib Model Code 2010, the scope was broadened through the stress field method that was introduced as a complementary tool....journal article 2023
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Ferreira, J.P. (author), Ferras, David (author), Covas, Dídia I.C. (author), Kapelan, Z. (author)Stormwater management model (SWMM) software has recently become a modeling tool for the simulation of intermittent water supply systems. However, SWMM is not capable of accurately simulating the air behavior in the pipe-filling phase, missing therefore a relevant factor during pipe pressurization. This work proposes the integration of a...journal article 2023
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Filgueiras, Manuel (author), Gkiotsalitis, Konstantinos (author), Yap, M.D. (author), Cats, O. (author), Lobo, António (author), Ferreira, Sara (author)A transit network design frequency setting model is proposed to cope with the postpandemic passenger demand. The multiobjective transit network design and frequency setting problem (TNDFSP) seeks to find optimal routes and their associated frequencies to operate public transport services in an urban area. The objective is to redesign the...journal article 2023