<p>Based on the independently developed water jet experimental platform, experiments and numerical studies were conducted on the inclined jet erosion of cohesive soil under different jet velocities (U<sub>0</sub>), inclination angles (θ), and target distances (h) to reveal the dynamic evolution characteristics of the three-dimensional flow field inside the erosion hole. A physical model for cohesive soil jet scouring was established, in which the Bingham rheological parameters were incorporated into the solver via User-Defined Function (UDF), and the Volume of Fluid (VOF) method was employed to track the evolution of the water–soil interface. Experimental results indicate that, with increasing θ, the scour hole morphology gradually transforms from “deep and narrow” to “shallow and wide,” accompanied by a significant reduction in sediment accumulation and a marked enhancement in inner-wall stability. The maximum scour depth (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\varepsilon_{m}\)</EquationSource> </InlineEquation>), radius (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\({\text{r}}_{{\text{m}}}\)</EquationSource> </InlineEquation>), and volume (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\xi\)</EquationSource> </InlineEquation>) increase markedly with increasing U₀. When θ = 30°, the scour hole length and volume reach their maximum values, with <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\({\text{r}}_{{\text{m}}}\)</EquationSource> </InlineEquation> = 832 mm and <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\( \sqrt[3]{\xi } \)</EquationSource> </InlineEquation> = 511 mm, respectively. Whereas the maximum scour depth <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\varepsilon_{m}\)</EquationSource> </InlineEquation> = 590 mm is obtained at θ = 22.5°. The erosion process induced by the inclined jet can be divided into three stages: initial impingement, unstable expansion, and dynamic equilibrium, during which the scour hole morphology evolves from an elliptical shape to a wing-like pattern and ultimately develops into a stable scour hole. On this basis, a dimensionless scouring equation for predicting the equilibrium scour depth was established by combining theoretical analysis with experimental data. The scour depth exhibits a logarithmic growth with dimensionless time. This study provides important guidance for optimizing subsea pipeline installation and improving the efficiency of dredging operations.</p>

Experimental and simulation study on the scouring of cohesive soil by submerged circular turbulent obliqued jet

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发表日期：

2026年5月27日

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Shengqun Jiang,
Jixiang Yue,
Yancong Liu,
Yangli Zhou

摘要

Based on the independently developed water jet experimental platform, experiments and numerical studies were conducted on the inclined jet erosion of cohesive soil under different jet velocities (U₀), inclination angles (θ), and target distances (h) to reveal the dynamic evolution characteristics of the three-dimensional flow field inside the erosion hole. A physical model for cohesive soil jet scouring was established, in which the Bingham rheological parameters were incorporated into the solver via User-Defined Function (UDF), and the Volume of Fluid (VOF) method was employed to track the evolution of the water–soil interface. Experimental results indicate that, with increasing θ, the scour hole morphology gradually transforms from “deep and narrow” to “shallow and wide,” accompanied by a significant reduction in sediment accumulation and a marked enhancement in inner-wall stability. The maximum scour depth ( \(\varepsilon_{m}\) ), radius ( \({\text{r}}_{{\text{m}}}\) ), and volume ( \(\xi\) ) increase markedly with increasing U₀. When θ = 30°, the scour hole length and volume reach their maximum values, with \({\text{r}}_{{\text{m}}}\) = 832 mm and \( \sqrt[3]{\xi } \) = 511 mm, respectively. Whereas the maximum scour depth \(\varepsilon_{m}\) = 590 mm is obtained at θ = 22.5°. The erosion process induced by the inclined jet can be divided into three stages: initial impingement, unstable expansion, and dynamic equilibrium, during which the scour hole morphology evolves from an elliptical shape to a wing-like pattern and ultimately develops into a stable scour hole. On this basis, a dimensionless scouring equation for predicting the equilibrium scour depth was established by combining theoretical analysis with experimental data. The scour depth exhibits a logarithmic growth with dimensionless time. This study provides important guidance for optimizing subsea pipeline installation and improving the efficiency of dredging operations.