The primary environmental impact caused by seawater intake operation is marine life impingement resulting from the intake velocity. Environmental Protection Agency (EPA) of United State has regulated the use of velocity cap fitted at intake structures to reduce the marine life impingement. The engineering design parameters of velocity cap has not been well explored to date. This study has been set to determine the fundamental relationships between intake velocity and design parameters of velocity cap, using computational fluid dynamic (CFD) model. A set of engineering design criteria for velocity cap design are derived. The numerical evidence yielded in this study show that the velocity cap should be designed with vertical opening (H_vc) and horizontal shelf (ℓ_vc). The recommended intake opening ratio (O_r) shall be 0.36 V_r^−0.31, where O_r = H_vc/ℓ_vc and V_r =V₀/V_pipe. V_o is the velocity at the intake window and V_pipe is the suction velocity at the intake pipe. The volume ratio (ω_r) between the velocity cap (ω_vc) and intake tower (ω_IT) is recommended at 0.11 V_r^−1.23. The positive outlooks that yielded from this study can be served as a design reference for velocity cap to mitigate the detrimental impacts from the existing intake structure.

中文翻译：

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进气道周围流场工程设计准则的推导：数值模拟研究

海水取水作业对环境的主要影响是取水速度对海洋生物的影响。美国环境保护署（EPA）规定了安装在进气口结构上的速度帽的使用，以减少对海洋生物的影响。迄今为止，速度帽的工程设计参数尚未得到很好的探索。这项研究已设置为使用计算流体动力学（CFD）模型确定进气速度与速度上限设计参数之间的基本关系。得出了一套用于速度上限设计的工程设计标准。数值证据在这项研究表明，该速度上限应被设计成具有垂直开口（H产生_VC）和水平搁架（ℓ _VC）。推荐的进气口比（O _{- [R}）应是0.36 V _{- [R} ^-0.31，其中O _{- [R} = H _VC /ℓ _VC和V _{- [R} = V ₀ / V_管。V _o是进气窗处的速度，V _pipe是进气管处的吸气速度。的体积比（ω _{- [R}速度帽之间）（ω _VC）和进气塔（ω _IT）被推荐在0.11 V _{- [R} ^-1.23。这项研究得出的积极观点可以作为速度上限的设计参考，以减轻现有进气口结构的不利影响。