Three-dimension efflux velocity characteristics of marine propeller jets

Hamill, Gerard; Ryan, Dona; Kee, Charmaine

doi:10.1680/maen.14.00019

Cited by 9 publications

(13 citation statements)

References 8 publications

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“…Most of these equations are based on experimental studies (e.g. Chiew & Lim, 1996;Hamill, 1987;Hamill & McGarvey, 1996;Hamill, Kee, & Ryan, 2015;Hong, Chiew, & Cheng, 2013;Schokking et al, 2003;Stewart, 1992). Interestingly, Ryan, Hamill, and Johnston (2013) proposed a new methodology based on artificial neural networks to predict maximum erosion as a result of ship docking manoeuvring.…”

Section: Introductionmentioning

confidence: 99%

Erosion caused by propeller jets in a low energy harbour basin

Mujal-Colilles

Gironella²,

Sánchez‐Arcilla³

et al. 2016

Journal of Hydraulic Research

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Field data of a harbour basin are compared with analytical formulations for predicting maximum scouring depth due to propeller jets. Spatial data analysis of seven-year biannual bathymetries quantifies the evolution of the scouring hole along with the sedimentation process within a harbour basin. The maximum scouring depth is found to be of the order of the propeller diameter with a maximum scouring rate within the first six months of docking manoeuvring. Three of the analysed expressions yielded realistic results while observed discrepancies between the theoretical predictions and field data are related to scaling factors. The outcomes of this analysis can be extrapolated to other harbours to improve their management. The obtained results highlight the importance of field data in developing combined physical and numerical models.

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Section: Introductionmentioning

confidence: 99%

Erosion caused by propeller jets in a low energy harbour basin

Mujal-Colilles

Gironella²,

Sánchez‐Arcilla³

et al. 2016

Journal of Hydraulic Research

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“…Lam et al (2012) measured the axial, tangential and radial components of velocity at the efflux plane of a single propeller by using Laser Doppler Anemometry (LDA) method. Hamill et al (2015) investigated the efflux velocity from four different propellers operating at four rotational speeds and made comparison with the previous works. Hamill et al (2016) proposed the semi-empirical equations to determine the location, magnitude and distribution of the axial velocity within a free expanding propeller jet.…”

Section: Introductionmentioning

confidence: 99%

Ship Twin-propeller Jet Model used to Predict the Initial Velocity and Velocity Distribution within Diffusing Jet

Jiang

Lam

Cui

et al. 2019

KSCE Journal of Civil Engineering

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The current research proposed the theoretical model for ship twin-propeller jet based on the axial momentum theory and Gaussian normal distribution. The twin-propeller jet model is compared to the more matured single propeller jet model with good agreement. Computational Fluid Dynamics (CFD) method is used to acquire the velocity distribution within the twin-propeller jet for understanding of flow characteristics and validation purposes. Efflux velocity is the maximum velocity within the entire jet with strong influences by the geometrical profiles of the blades. Twin-propeller jet model showed four-peaked profile at the initial plane downstream to the propeller compared to the two-peaked profile from a single-propeller. The four-peaked profile merges to be two-peaked velocity profile and then one-peaked profile due to the fluid mixing. Entrainment occurs between the ambient still water outside and the rotating flow within jet due to the high velocity gradient. The research proposes a twin-propeller jet theory with a serial of equations enabling the predictions of velocity magnitude within the jet.

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“…The problems within harbours and navigation channels associated with the close proximity of manoeuvring vessels, have been well discussed in a range of both case studies and research investigations, Fuehrer & Römisch (1977), Blaauw, H.G., and van de Kaa, E.J. (1978), Bergh & Cederwall (1981), Berger et al (1981), Fuehrer et (1981), Verhey et al (1987), Hamill (1987), Chait (1987), Stewart (1992), Hashmi (1993), Qurrain (1994), Froehlich & Shea (2000), Sumer & Fredsoe (2002), Hong et al (2013), Geisenhainer & Aberle (2013) and Hamill et al (2014). Guidelines for engineers have been developed (PIANC (2015), BAW (2010) and CIRIA (2007)) incorporating the influence of engineering surfaces, beds and slopes.…”

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confidence: 99%

Predicting axial velocity profiles within a diffusing marine propeller jet

Hamill

Kee²

2016

Ocean Engineering

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12A full understanding of the hydrodynamic processes within the jet produced by a manoeuvring 69fully understood if an engineer is to be able to quantify any scouring damage that may occur, 70and, more importantly, size protection systems to be deployed to prevent further damage. 72The flow field produced by the action of rotating propeller blades is complex in nature. Near 73to the propeller, the passing blades and rotating hub influence the characteristics of the flow. 74As the jet diffuses downstream, the velocity characteristics become similar to a submerged 102The propellers used in this investigation varied in size (Dp), numbers of blades (N), pitch to 103 diameter ratios (P'), thrust coefficients (Ct), rake and blade area ratios (β), as shown in Table 104 1. The number of propeller blades varied from three to six. The pitch to diameter ratio ranged 107The blades of propeller 1, 3 and 4 had no forward inclination i. Equation 3 124 125The rotational speeds used in the programme of work were based on standard Froudian scale 134The propellers were operated across a range of speeds that bounded these target values, 135and these are listed in full in Table 2. 137The Reynolds numbers for the propellers operating at these rotational speeds ranged from 138

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Three-dimension efflux velocity characteristics of marine propeller jets

Cited by 9 publications

References 8 publications

Erosion caused by propeller jets in a low energy harbour basin

Erosion caused by propeller jets in a low energy harbour basin

Ship Twin-propeller Jet Model used to Predict the Initial Velocity and Velocity Distribution within Diffusing Jet

Predicting axial velocity profiles within a diffusing marine propeller jet

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