A Lagrangian particle model for one-dimensional transient pipe flow with moving boundary

Engineering Applications of Computational Fluid Mechanics, Journal Year: 2025, Volume and Issue: 19(1)

Published: Jan. 27, 2025

Language: Английский

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Rapid flood inundation mapping by integrating deep learning-based image super-resolution with coarse-grid hydrodynamic modeling

Engineering Applications of Computational Fluid Mechanics, Journal Year: 2025, Volume and Issue: 19(1)

Published: March 25, 2025

Efficient and accurate flood inundation mapping is essential for risk assessment, emergency response, community safety. The deep learning-enabled rapid simulation demonstrates superior computational efficiency compared to traditional hydrodynamic models. However, most learning-based models currently focus on predicting the maximum water depth face challenges in generalizing rainfall events of different durations. This paper proposes a fast method based image super-resolution, utilizing novel DenseUNet architecture predict velocity temporal events. proposed integrates physical catchment characteristics enhance resolution maps generated by coarse-grid model using deep-learning model. applied rural-urban Shenzhen River southern China. effectively reproduces test against fine-grid model, achieving root mean square errors below 0.06 0.07 m/s, respectively, with percentage bias within ±5%. For prediction, exhibits Nash-Sutcliffe Pearson correlation coefficient exceeding 0.99. Similarly, both metrics exceed 0.94. outperforms over 2800 times. developed this study regression classification performance commonly used ResUNet UNet architectures. robust wide range super-resolution scale factors. presents an efficient surrogate mapping, providing valuable insights applying methods simulation.

Language: Английский

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Analysis and mitigation of post-bore noises in modeling mixed flows in closed conduits

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(4)

Published: April 1, 2025

In this paper, the author analyzes post-bore noise problem in mixed pipe-flow modeling, which uses shock-capturing methods within single-equation frameworks. The study reveals that origin of these numerical noises following pipe-filling is sudden jump from free-surface gravity wave speed c to a significantly higher constant pipe acoustic ac during surcharging. This abrupt transition results an excessively large Laplacian type dissipation, overwhelms physical fluxes, reverses their directions, and leads significant decreases mass momentum, particularly at bore front where concavity conserved variable not small relatively sharp profile, periodically manifest initial pressurization cell. Based on analyses above underlying mechanisms, proposes novel noise-mitigation technique: oscillation mitigation (PBOM) approach, diminishes shock profile by allowing ventilated cells ahead fill more rapidly, introduces new smooth transient function for signal prevent viscosity coefficient. Some preliminary tests validate proposed approach.

Language: Английский

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SwinFlood: A hybrid CNN-Swin Transformer model for rapid spatiotemporal flood simulation

Journal of Hydrology, Journal Year: 2025, Volume and Issue: unknown, P. 133280 - 133280

Published: April 1, 2025

Language: Английский

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A depth‐integrated SPH framework for slow landslides

International Journal for Numerical and Analytical Methods in Geomechanics, Journal Year: 2024, Volume and Issue: 48(16), P. 3848 - 3875

Published: Aug. 8, 2024

Abstract Slow and very slow landslides can cause severe economic damage to structures. Due their velocity of propagation, it is possible take action such as programmed maintenance or evacuation affected zones. Modeling an important tool that allows scientists, engineers, geologists better understand causes predict propagation. There are many available models different complexities which be used for this purpose, ranging from simple infinite landslide implemented in spreadsheets fully coupled 3D models. This approach expensive because the time span problems studied (sometimes years), simpler methods depth‐integrated could provide a good compromise between accuracy cost. However, there, step limitation due CFL condition (which states has slower than ratio node spacing physical waves results increments order one‐10th second on occasions. paper extends technique been past glacier evolution using finite differences elements SPH The based assuming (i) flow shallow, (ii) rheological behavior determining propagation viscoplastic, (iii) accelerations neglected. In case, model changes hyperbolic parabolic, with increment much larger classic formulations.

Language: Английский

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Development of Pipeline Transient Mixed Flow Model with Smoothed Particle Hydrodynamics Based on Preissmann Slot Method

Water, Journal Year: 2024, Volume and Issue: 16(8), P. 1108 - 1108

Published: April 12, 2024

The accurate modeling and understanding of complex transient mixed pipe flows is crucial for the optimal design safe efficient operation in pipeline systems such as urban drainage systems. Currently, predominant approach free-surface-pressurized relies on grid-based numerical schemes, with comparatively limited capability exploring its phenomena. This study proposed a novel one-dimensional model that integrates smoothed particle hydrodynamics (SPH) method Preissmann slot (PSM) to explore systems, better potential more flow Empirical parameters SPH-PSM were optimized improving accuracy stability, applicable range these empirical was recommended. performances evaluated by different regimes, including one free surface case, fully pressurized two mixed-flow cases. simulation results regimes demonstrated high level agreement reference data, indicating good simulating Therefore, can be an alternative way modeling, exploring,

Language: Английский

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Modeling Transient Mixed Flows in Sewer Systems with Data Fusion via Physics-Informed Machine Learning

Water Research X, Journal Year: 2024, Volume and Issue: 25, P. 100266 - 100266

Published: Oct. 15, 2024

Language: Английский

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