Influence of turbulence closure models on the vortical flow field around a submarine body undergoing steady drift

Manoeuvring underwater vehicles experience complex three-dimensional flow. Features include stagnation and boundary layer separation along a convex surface. The resulting free vortex sheet rolls up to form a pair of streamwise body vortices. The track and strength of the body vortex pair results in a nonlinear increase in lift as body incidence increases. Consequently, accurate capture of the body vortex pair is essential if the flow field around a manoeuvring submarine and the resulting hydrodynamic loading is to be correctly found. This work highlights the importance of both grid convergence and turbulence closure models (TCMs) to the strength and path of the crossflow-induced body vortices experienced by the DOR submarine model at an incidence angle of 15°. Five TCMs are considered; Spalart–Allmaras, k-ε, k-ω, shear stress transport, and the SSG Reynolds stress model. The SSG Reynolds stress model shows potential improvements in predicting both the path and strength of the body vortex over standard one- and two-equation TCMs based on an eddy viscosity approach.     

Strategies of developing part administration in Ireland

This paper reivews a programme recently undertaken by the Irish Government aimed at reforming the administration of Irish ports. Arising from that programme, and as a result of legislative changes, eight key ports were vested as commerical harbour companies (prior to this they were administered by large Boards and were very restricted in their ability to perform commercially). The context for the paper is the global trend towards port reformation, and the paper draws particuarly on the effects of the privatization of UK ports. The paper starts with a review of the role of parts, both generally and within the context of Ireland's growing, geographically peripheral, economy. Observations of the UK ports privatization process are next considered. The history, development and recent performance of Irish ports, together with port investment strategies, are critiqued and the background to the recent programme of administrative reform undertaken by the Irish Government concerning the ports is reviewed. Various observations from a number of sources (including 12 interviews by the authors with key actors in the sector) on the reform process are discussed. It is concluded that there is no uniformity of opinion as to the suitability of the chosen model for Irish ports administration and that it is too soon to judge whether it has been a success (the eight ports were commercialized in March 1997). The paper concludes that, given the critical role of ports within the Irish economy, the situation should be periodically reviewed to ascertain the current applicability of the extant port administration model.     

Strategies of developing part administration in Ireland

This paper reivews a programme recently undertaken by the Irish Government aimed at reforming the administration of Irish ports. Arising from that programme, and as a result of legislative changes, eight key ports were vested as commerical harbour companies (prior to this they were administered by large Boards and were very restricted in their ability to perform commercially). The context for the paper is the global trend towards port reformation, and the paper draws particuarly on the effects of the privatization of UK ports. The paper starts with a review of the role of parts, both generally and within the context of Ireland's growing, geographically peripheral, economy. Observations of the UK ports privatization process are next considered. The history, development and recent performance of Irish ports, together with port investment strategies, are critiqued and the background to the recent programme of administrative reform undertaken by the Irish Government concerning the ports is reviewed. Various observations from a number of sources (including 12 interviews by the authors with key actors in the sector) on the reform process are discussed. It is concluded that there is no uniformity of opinion as to the suitability of the chosen model for Irish ports administration and that it is too soon to judge whether it has been a success (the eight ports were commercialized in March 1997). The paper concludes that, given the critical role of ports within the Irish economy, the situation should be periodically reviewed to ascertain the current applicability of the extant port administration model.