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Water-jet propulsion system with vectorised thrust
Published in Petar Georgiev, C. Guedes Soares, Sustainable Development and Innovations in Marine Technologies, 2019
A pump-jet, hydro-jet, or as it is called water jet is a device designed to produce a jet of water for marine propulsion. The traditional mechanical arrangement may be a ducted propeller (axial pump), centrifugal pump or mixed flow pump. The design also incorporates an intake to provide water to the pump and a nozzle to direct the flow of water out of the pump, see Figure 2.
Stationary Gas Turbines
Published in Don M. Pirro, Martin Webster, Ekkehard Daschner, Lubrication Fundamentals, 2017
Don M. Pirro, Martin Webster, Ekkehard Daschner
Gas turbines are used for marine propulsion when faster ship speed is required and where the ship operates primarily at full throttle. Reduced thermal efficiency with turbines and higher fuel costs often preclude its use in favor of diesel engines.
Prospects for Nuclear Microreactors: A Review of the Technology, Economics, and Regulatory Considerations
Published in Nuclear Technology, 2023
G. Black, D. Shropshire, K. Araújo, A. van Heek
The final profile market analyzed in the INL study is Marine Propulsion. The use of microreactors is well suited for marine propulsion for commercial marine vessels that require 40 MW or less power or for larger vessels, where several microreactors could be stacked together. In addition to the negative environmental consequences of using bunker fuel for virtually all commercial marine transport, the economics of using microreactors are enhanced by the increased availability of cargo space due to the removal of bunker fuel storage. Countries with high potential for microreactor deployment in marine transport are those with either very large ports capable of handling many ships, those with many smaller commercial ports, or those that serve as shipping hubs for other countries in their region.
Engineering Laboratory Experiments – a Typology
Published in Engineering Studies, 2022
According to Walter Vincenti, Systematic Parameter Variation (PV) is a ‘procedure of repeatedly determining the performance of some material, process, or device while systematically varying the parameters that define the object of interest or its conditions of operation’.20 According to the PV method, first all relevant variables must be identified, then they are systematically varied and, finally, the results of the dependent variable(s) are presented in an orderly fashion in tables. The normative, more distant results (e.g. the highest lift/drag coefficient or the lowest resistance, etc.) are closely connected to these descriptive, proximate results. In 1901, the Wright brothers (bicycle repairers by trade) famously designed the first systematic wind tunnel PV experiments. Another well-known and more recent example of PV is the Wageningen B-screw series (1930s–1970s), in which the torque and thrust of 120 propeller models are measured (ranging between two and seven blades), at different speeds, and for blade-propeller area ratios between 0.3 and 1.05. The results are still being discussed in modern handbooks on marine propulsion.21
Optimisation scheme applied to the Voith-Schneider propulsion system using genetic algorithm
Published in Ships and Offshore Structures, 2021
Mohammad Bakhtiari, Hassan Ghassemi, Abdollah Sakaki, Guanghua He
In a marine cycloidal propulsion system, the propulsion and manoeuvring units are combined together as a single unit. Therefore, no separate rudder is required for manoeuvring. Nandy et al. (2015) reported that a marine cycloidal propeller has four to six blades. The VSP is a specialised marine propulsion system. It is used primarily for ships that have to satisfy particularly demanding safety and manoeuvrability requirements. VSP consists of a rotating disk on which outer end blades are connected parallel to the rotation axis. The pitch angle of the blades is variable and fulfils an overlaid motion when doing one revolution. This motion can be influenced to generate a thrust in the desired direction. The magnitude of the thrust can be set by the rotational speed of the disk. Since the blade pitch can be set nearly step-less within a short time, the thrust generation and manoeuvring are very fast and accurate compared to propeller-based propulsions. VSP permits continuously variable thrust adjustment through 360°. Thus, the VSP has no preferential direction of thrust and allows infinite variation in the magnitude and direction of thrust.