Tidal energy is one of the world's most predicable renewable energy sources and therefore holds great potential to be a valuable building block for the decarbonisation of electricity production. This paper focuses on a Venturi shaped duct structure (shroud) to accelerate the flow speed at a vertical axis tidal turbine utilising the low static pressure created at the exit of the shroud. This concept is known as a Davidson Hill Venturi (DHV) turbine. By constructing the nozzle and diffusor using hydrofoils, initial demonstrations indicate increased system efficiency. However, owing to the potential number of geometric and structural hydrofoil variations, only a general description of the location of the hydrofoils is provided in order to facilitate modelling while allowing for future geometric variations to be devised. The conducted investigations focus on the influence of the nozzle and diffusor sections as the main geometry variations, identifying the length component in the orthogonal direction as the dominant parameter. By modelling multiple combinations of these variables it is clear that higher fluid velocities result in larger forces which must be supported by the devices structure. Small adjustments to the reference geometries hydrofoil placement and spacing provided improvements to the fluid flow. Thus, taking the slight alteration to the geometry as this papers main outcome, a further in a 3D-simulation study, including turbine interaction and rotation, is to be completed to fully characterise the systems benefits. The insights gained from this work will allow a reduction in computational costs for the detailed optimisation and study into the adaption of the concept for a wide range of (environmental) boundary conditions.

潮汐能是世界上最可预测的可再生能源之一，因此具有成为电力生产脱碳的重要组成部分的巨大潜力。本文重点介绍一种文丘里管结构（护罩），利用护罩出口处产生的低静压来加速垂直轴潮汐涡轮机的流速。这个概念被称为戴维森山文丘里 (DHV) 涡轮机。通过使用水翼构造喷嘴和扩散器，初步演示表明系统效率有所提高。然而，由于几何和结构水翼变化的潜在数量，仅提供水翼位置的一般描述，以便于建模，同时允许设计未来的几何变化。所进行的调查主要集中在喷嘴和扩散器部分作为主要几何形状变化的影响，将正交方向的长度分量确定为主要参数。通过对这些变量的多种组合进行建模，可以清楚地看出，更高的流体速度会产生更大的力，而这些力必须由设备结构支撑。对参考几何形状水翼放置和间距的小调整改进了流体流动。因此，将对几何结构的微小改动作为本文的主要成果，将完成进一步的 3D 模拟研究，包括涡轮机相互作用和旋转，以充分表征系统优势。