150 research outputs found
Process-based modelling of hydro- and morphodynamics around the Anmok submerged breakwater
No full textThe use of the detached offshore submerged breakwater (SBW) for coastal protection has an increasing popularity due to its low aesthetic impact on the natural environment. Submerged breakwaters however have only rarely been adopted and therefore its efficacy remains largely unknown (Ranasinghe et al. 2010). Shoreline erosion has been reported in the lee of submerged breakwaters in several field observations and therefore a better understanding of the characteristics of the shoreline response to submerged breakwaters is required. In this thesis insight is gained in the hydrodynamic patterns and the associated morphological response around a constructed submerged breakwater at the frequently monitored field site Anmok beach and in general the capability to reliably simulate coastal morphological response to submerged breakwaters is developed. In addition better understanding on modelling severe wave conditions in Delft3D has led to new possibilities with this model.Civil Engineering and GeosciencesHydraulic Engineerin
Process-based modelling of morphological response to submerged breakwaters
No full textSubmerged breakwaters (SBWs) are becoming increasingly popular as alternative coastal defence system due to the lack of impact on beach amenity and aesthetics compared to common emerged beach protection measures. However, the recent significant amount of failing SBWs resulting in additional shoreline erosion reported in [Ranasinghe and Turner 2006], indicates the importance of understanding the driving processes of salient development before routinely adopting SBWs in practice. The main objective of this thesis is to gain more insight into single shore-parallel detached SBW induced hydrodynamic processes driving morphological changes. In order to study SBW induced hydrodynamic conditions resulting in morphological response, a depth-averaged Delft3D model is used. By online coupling of Delft3D-FLOW and SWAN, the wave-current interaction is accounted. To exclude site-specific conditions, an idealized approach is used, including an alongshore uniform beach profile and shore normal short wave forcing. For this idealized situation, a sensitivity analysis of numerical parameters is performed, as well as a validation on individual SBW induced processes based on published literature. By examining the cross- and alongshore momentum balance for a variety of results from numerical simulations only changing alongshore length and offshore distance of the SBW, dominant SBW induced alongshore differences in water level and resulting currents are explained in detail. In addition, SBW design parameters are studied using the same momentum balances. Besides offshore distance, alongshore length of the SBW and directionality of the incoming waves, these include the crest width, crest height, incoming wave height and breakwater roughness. To confirm the findings from the hydrodynamic analysis as the important driving processes of SBW induced morphological changes, additional morphological simulations are included and morphological SBW induced response is compared to initial hydrodynamic conditions. As a result, a computationally efficient depth-averaged Delft3D model is obtained, which is capable of simulating SBW induced processes accurately compared to published literature. From the idealized simulations, more insight is given in two distinct SBW induced processes driving morphological response. These processes reducing nearshore water level set-up are the spatial distribution of wave forcing (commonly referred as wave sheltering effect) and the momentum balance between wave forcing and bottom stresses over the SBW. In addition to the parameters presented in [Ranasinghe et al. 2010], the breakwater roughness and directional spreading of waves are important parameters to take into account when constructing SBWs. Morphological simulations confirm the relation between the hydrodynamic processes described and the morphological response to SBWs. The ability of Delft3D to simulate morphological response to SBWs, enables a powerful numerical tool for future studies on SBW induced (morphological) processes.Hydraulic EngineeringCivil Engineering and Geoscience
\u3cem\u3eThe Form of Politics: Aristotle and Plato on Friendship\u3c/em\u3e by John Von Heyking
No full textHeyking’s ascent from Aristotle to Plato implies that something Platonic was lost in Aristotle’s accounts of friendship and politics. Plato’s views on love and soul turn out to have more in common with early Christianity. Stressing differences between eros and thumos, using Voegelin’s categories to discuss the Platonic Good, and expanding on Heyking’s use of Hermes, I show how tragic culture and true politics can be further enhanced by refining erotic friendship, repudiating Augustinian misanthropy, positing minimum doctrines about soul and city, and basing reason on Hermes rather than Apollo
Ass, You Like It? Shakespeare\u27s \u3cem\u3eA Midsummer Night\u27s Dream\u3c/em\u3e as Political Philosophy
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Trojan Horse or Troilus\u27s Whore? Pandering Statecraft and Political Stagecraft in \u3cem\u3eTroilus and Cressida\u3c/em\u3e
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