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Numerical model of so2 scrubbing with seawater applied to marine engines

Lamas M. I., Rodríguez C. G., Rodríguez J. D., Telmo J.

Polish Maritime Research

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2016

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nr 2

42--47

EN

The present paper proposes a CFD model to study sulphur dioxide (SO2) absorption in seawater. The focus is on the treatment of marine diesel engine exhaust gas. Both seawater and distilled water were compared to analyze the effect of seawater alkalinity. The results indicate that seawater is more appropriate than distilled water due to its alkalinity, obtaining almost 100% cleaning efficiency for the conditions analyzed. This SO2 reduction meets the limits of SOx emission control areas (SECA) when operating on heavy fuel oil. These numerical simulations were satisfactory validated with experimental tests. Such data are essential in designing seawater scrubbers and judging the operating cost of seawater scrubbing compared to alternative fuels.

2

Numerical model to study the valve overlap period in the Wärtsilä 6L 46 four-stroke marine engine

Lamas M. I., Rodríguez C. G., Rebollido J. M.

Polish Maritime Research

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2012

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nr 1

31-37

EN

In this paper, a CFD (Computational Fluid Dynamics) analysis was carried out to study the Wärtsilä 6L 46 medium-speed, four-stroke marine engine. For the purpose, the commercial software ANSYS Fluent 6.3 was employed. The aim is to analyze the scavenging of gases, especially during the valve overlap period. Particularly, the pressure, velocity and mass fraction fields were numerically obtained. In order to validate the CFD results, the in-cylinder pressure was successfully compared to experimental measurements for the exhaust, intake and compression strokes of the cylinder operation. This model can be used in future works to improve the performance of these engines because the information provided is very useful to identify regions in which the pressure, velocity or distribution of gases are inadequate. Besides, to compute the quantity of burnt gases which remain inside the cylinder, fresh charge which is expelled through the exhaust valves and study the influence of parameters such as the exhaust and intake pressures, engine speed, cam profile design, etc.

3

Three-dimensional cfd analysis to study the thrust and efficiency of a biologicallyinspired marine propulsor

Lamas M. I., Rodríguez J. D., Rodríguez C. G., González P. B.

Polish Maritime Research

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2011

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nr 1

10-16

EN

Aquatic animals, which are the result of many millions of years of evolutionary optimization, are very quick, efficient, robust, and versatile. Accordingly, biologically-inspired mechanisms which emulate the movement of animals have recently become very popular. For the efficient design of a propulsion system it is very important to analyze the fluid flow in detail. CFD (Computational Fluid Dynamics) has become a powerful technique to understand the phenomena because it gives extensive information about the fluid flow characteristics. In the present work, a propulsion system consisting of an undulating fin which emulates the fish swimming was built. In order to optimize the mechanism, several undulating configurations were studied using a 3D turbulent CFD model. The thrust, drag, efficiency and hydrodynamic characteristics were analyzed. Furthermore, it was shown that the efficiency and thrust depend strongly on the oscillation frequency, amplitude and wavelength. In order to validate this CFD model, the numerically obtained thrust was successfully compared with experimental results from the laboratory mechanism.