Natural earth-bounded channel flows usually subject to various sidewall turbulences, i.e. in the form of secondary currents, due to non-constant channel shapes at different sections. This paper investigates an improved Shiono-Knight model (SKM) by combining it with a Multi-Zonal (MZ) method (proposed by Pu, 2019) to represent lateral flow turbulence and secondary currents in different shapes of open channel, i.e. rectangular and trapezoidal. By applying the proposed analytical model to both rectangular and trapezoidal channel flows, we have inspected different streamwise velocity characteristics across transverse direction generated by their sidewalls in order to provide crucial fundamental understanding to real-world natural flow system. The proposed model has also been validated via various experimental data conducted in national UK Flood Channel Facility (UK-FCF). It has been observed that the trapezoidal channel has created a larger sidewall zone where secondary current can affect flow velocity; however, the intensity of the secondary flow in trapezoidal channel has been found lesser than that of the rectangular channel. By improving the modelling of natural flow at sidewall, the studied approach could be adapted into different existing analytical models to improve their accuracy.

由于在不同部分的非恒定通道形状，天然的自然界通道流通常会受到各种侧壁湍流的影响，即以次级电流的形式。本文研究了一种改进的Shiono-Knight模型（SKM），将其与Multi-Zonal（MZ）方法（Pu，2019年提出）相结合，以表示不同形式的明渠（即矩形和梯形）中的横向流动湍流和二次流。通过将所提出的分析模型应用于矩形和梯形通道流，我们检查了由其侧壁产生的横向上不同的水流速度特性，以便为现实世界的自然流系统提供至关重要的基础知识。提议的模型也已通过在英国国家洪水渠道设施（UK-FCF）中进行的各种实验数据进行了验证。已经观察到梯形通道已经形成了较大的侧壁区域，在该侧壁区域中次级电流会影响流速。但是，发现梯形通道中的二次流强度要小于矩形通道中的二次流强度。通过改进侧壁自然流动的建模，可以将研究方法应用于不同的现有分析模型中，以提高其准确性。