Experiments on a Flettner rotor at critical and supercritical Reynolds numbers

Bordogna, Gloria; Muggiasca, Sara; Giappino, Stefano Giuseppe; Belloli, Marco; Keuning, J A; Huijsmans, R.H.M.; Veer, A P

doi:10.1016/j.jweia.2019.02.006

Cited by 37 publications

(27 citation statements)

References 12 publications

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“…The power consumed by the motor and the thrust produced from the Flettner rotor will regulate the amount of the main engine power that can be replaced. The produced thrust can be calculated as the summation of the lift and drag forces in the ship direction (Ballini et al 2017 ; Bentin et al 2016 ; Bordogna et al 2020 ; Bordogna et al 2019 ; De Marco et al 2016 ; Kray et al 2012 ; Mittal and Kumar 2003 ; Traut et al 2014 ).…”

Section: Flettner Rotors’ Principles and Fundamentalsmentioning

confidence: 99%

Harnessing wind energy on merchant ships: case study Flettner rotors onboard bulk carriers

Seddiek

Ammar

2021

Environ Sci Pollut Res

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Shipping faces challenges of reducing the dependence on fossil fuels to align with the international regulations of ship emissions reduction. The maritime industry is in urgent need of searching about alternative energy sources for ships. This paper highlights the applicability of harnessing wind power for ships. Flettner rotors as a clean propulsion technology for commercial ships are introduced. As a case study, one of the bulk carrier ships operating between Damietta port in Egypt and Dunkirk port in France has been investigated. The results showed the high influence of the interaction between ship course and wind speed and direction on the net output power of Flettner rotors. The average net output power for each rotor will be 384 kW/h. Economically, the results reveal that the use of Flettner rotors will contribute to considerable savings, up to 22.28% of the annual ship’s fuel consumption. The pay-back period of the proposed concept will be 6 years with a considerable value of levelized cost of energy. Environmentally, NO x and CO 2 emissions will be reduced by 270.4 and 9272 ton/year with cost-effectiveness of $1912 and $55.8/ton, respectively, at annual interest rate of 10%.

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Section: Flettner Rotors’ Principles and Fundamentalsmentioning

confidence: 99%

Harnessing wind energy on merchant ships: case study Flettner rotors onboard bulk carriers

Seddiek

Ammar

2021

Environ Sci Pollut Res

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“…The apparent wind angle (AWA) and apparent wind speed (AWS) were assumed to be constant on each strip, but did vary between strips due to the wind profile and the ship motions. The interaction between rotor sails was neglected, which is a valid assumption in apparent beam wind conditions, but becomes questionable close to head wind (AWA − → 0 o ) and tail wind (AWA − → 180 deg) conditions [19,7,5].…”

Section: Computation Of Sail Loadsmentioning

confidence: 99%

“…Propulsion forces vary due to change of propeller loading and inflow angles, (5) The machinery system are affected through change of propulsion point (6) Roll and pitch damping increases due to the presence of sails which affects the added resistance in waves. (7) Inflow on bilge keels is considerably altered. Modeling each of these effects individually poses a challenge in itself, and so does the treatment of the coupling between the interacting effects [5].…”

Section: Nomenclature 1 Introductionmentioning

confidence: 99%

“…It is in practice impossible to fulfill Reynolds number similarity for wind propulsor systems at the same time, and this is a significant issue for e.g. Flettner rotors and wing sails [7] Furthermore, there are technical challenges related to generation of a wind field (which ideally also could be dynamically changed during a test) around a moving object of appropriate quality in a hydrodynamic laboratory.…”

Section: Nomenclature 1 Introductionmentioning

confidence: 99%

“…For floating wind turbines, ReaTHM testing enabled to study the dynamical behaviour of large wind floating wind turbines [11,12], and put in evidence the effect of velocity-dependent eigenmodes that was then studied theoretically [13]. Back to the field of sail-assisted proplusion, advances have been made in the recent years in the numerical modeling of sails, based on analytical approaches [5], numerical studies [14] and wind tunnnel tests [7]. See the review in [5] for details.…”

Section: Nomenclature 1 Introductionmentioning

confidence: 99%

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Hydrodynamic testing of wind-assisted cargo ships using a cyber-physical empirical method

Sauder¹,

Alterskjær²

2021

Preprint

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A novel empirical method to study wind-assisted cargo ships is presented. The physical ship model, including propulsion units, interacts in real-time with a numerical sail model during free-running tests. Loads from the (virtual) sails are applied on the physical model using a cable-driven robot. All loads components except heave are applied with high accuracy and repeatability. The method is described thoroughly, and applied to investigate the benefits of wind assistance on a 190m bulk-carrier, equipped with four rotor sails. Key performance indicators for wind assistance are established when sailing in steady wind profiles of various directions and velocities, and a propulsion analysis is performed. An important conclusion is that the increase of hydrodynamic resistance due to heel, leeway and rudder (that balance transverse sail loads) is rather limited for this ship, except when sailing close-hauled in strong winds. It is also demonstrated that experiments in a unsteady (virtual) wind environment can be successfully conducted. The effect of turbulence on the motions of this ship are found to be very limited. The conclusion discusses the other types of studies that can be enabled by this novel cyber-physical empirical method.

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