Hydraulic Model Research Articles

Rarefied gas flow in functionalized microchannels

The interaction of rarefied gases with functionalized surfaces is of great importance in technical applications such as gas separation membranes and catalysis. To investigate the influence of functionalization and rarefaction on gas flow rate in a defined geometry, pressure-driven gas flow experiments with helium and carbon dioxide through plain and alkyl-functionalized microchannels are performed. The experiments cover Knudsen numbers from 0.01 to 200 and therefore the slip flow regime up to free molecular flow. To minimize the experimental uncertainty which is prevalent in micro flow experiments, a methodology is developed to make optimal use of the measurement data. The results are compared to an analysis-based hydraulic closure model (ACM) predicting rarefied gas flow in straight channels and to numerical solutions of the linearized S-model and BGK kinetic equations. The experimental data shows that if there is a difference between plain and functionalized channels, it is likely obscured by experimental uncertainty. This stands in contrast to previous measurements in smaller geometries and demonstrates that the surface-to-volume ratio of 0.4 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}m-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} seems to be too small for the functionalization to have a strong influence and highlights the importance of geometric scale for surface effects. These results also shed light on the molecular reflection characteristics described by the TMAC.

Unsaturated hydraulic property measurements of subtropical anthropogenic (purple) soils in China

AbstractMany anthropogenic soils, often referred to as red bed or purple soils, are distributed in various areas of southern China. Purple soils typically are highly weathered and often lead to natural and engineering hazards because of their relatively poor water retention properties. Knowledge of the unsaturated soil hydraulic properties of purple soils is crucial for their optimal management and various assessment studies. In this work, the hydraulic properties of purple soils from southern China were measured in the laboratory over the full moisture range using a combination of evaporation (HYPROP) and psychrometer (WP4C) approaches. Measured data were analyzed in terms of four different unimodal and bimodal soil hydraulic models. The measurements and analyses showed that bimodality was not overly significant for most samples. The good fit of the Peters–Durner–Iden models furthermore suggested that corner and film flows were important under relative dry conditions. Existing soil pedotransfer functions were found to provide a fairly close match for the slope of water retention curves with the exception of near saturated water contents and the saturated conductivity. To the best of our knowledge, this is the first time that unsaturated hydraulic data of purple soils are provided over the full moisture range.

Calibration of intermittent water supply systems hydraulic models under data scarcity

Abstract Intermittent water supply systems (IWSSs) are unable to meet customer demands due to water scarcity from the sources or due to economic or/and technical scarcity. Conversion to continuous water supply as a means of tackling IWSSs’ inherent problems of inequitable water distribution, limited water supply hours, high non-revenue water, system operation and maintenance costs, and poor water quality is essential for sustainable water supply. Modelling and optimisation techniques have been used to aid the conversion process, optimisation of the operation of these systems, and guiding leakage reduction actions. However, modelling IWSSs have several challenges. These include the lack of accepted existing modelling techniques that include leakage modelling and the lack of comprehensive methodology for calibrating IWSS hydraulic models under limited calibration data. This study proposes a methodology for calibrating IWSS hydraulic models that include leakage modelling. The proposed methodology involves distinct steps to mitigate the problem of data scarcity, it eliminates the trial-and-error procedure of determining the leakage emitters' coefficients by using optimisation and it presents an approach for estimating the lower and upper bounds of the emitters' coefficients. The methodology was applied to a case study in Zambia. The calibration procedure gave accurate results given the limitation of data.

Simulation and optimization of unstable dynamic propagation of multiple fractures in the shale formation

Multi-cluster hydraulic fracturing of horizontal wells is a well-adopted technique with high efficiency to increase the production of tight and shale formations. However, the stress shadows among clusters pose challenges to the synchronous propagation of hydraulic fractures during multi-cluster fracturing. In order to explore the fracture propagation mechanism and characteristics under the influence of stress shadow in low-spacing staged multi-cluster fracturing, a three-dimensional hydraulic fracturing model was generated using a lattice-based method. This model considered the impact of geological and engineering parameters on the propagation behavior of multiple fractures in shale formation. A variable pumping approach is adopted, where the fracturing fluid is initially injected at a high rate and then transitioned to a lower rate. Afterward, a method was proposed to quantitatively assess the extent of fracturing in a specific area (i.e., the stimulated area), considering the impact of stress shadow within a single stage. The simulation results demonstrated significant differences in the fracture stimulation area due to the influence of each parameter in the case of uncontrollable geological factors and controllable engineering factors. An increase in both Young’s modulus and stress anisotropy of the reservoir results led to a corresponding increase in the total fracture stimulation area. As the principal stress orientation increased, the fracture stimulation area gradually decreased. In terms of operational parameters, the stimulated area of hydraulic fractures gradually decreased as the fracture spacing increased. With increasing injection rate, the stimulated area initially expanded and then decreased, peaking at an injection rate of 0.04 m3/s. These findings can provide valuable insights into the propagation behavior of multi-cluster hydraulic fractures under uncertain parameters, with significant implications for future engineering applications.

Improved flood depth estimation with SAR image, digital elevation model, and machine learning schemes

Study regionNhat Le river basin, the floodplains of Central coast of Vietnam. Study focusFlood disasters have a significant impact on population and economies worldwide. To accurately assess flood damage, it is crucial to estimate the water depth and predict the potential spread of damage. However, conventional methods of estimating flood depth can be time-consuming and costly due to the large amount of data required from hydraulic and rain-runoff models. To overcome these limitations, we propose a new approach that integrates a machine learning (ML) algorithm with a floodwater depth estimation tool (FwDET) based on SAR imagery and digital elevation models (DEMs). To evaluate our approach, we trained and tested six ML regression algorithms using 804 sets of inventory flood depth data from the historic flood on the Nhat Le River in Vietnam in October 2020 as the dependent variable. This approach significantly improves flood depth prediction accuracy, enabling a faster and more cost-effective estimation of flood damage. New hydrological insights for the regionOur research shows that by combining ML with FwDET, we were able to significantly enhance water depth prediction accuracy. We observed a 25.05% increase in the R2 coefficient and a 13.46% increase in the R coefficient. We recommend integrating satellite imagery, DEM, and ML for flood depth predictions, especially for floodplains with similar topographical conditions as the Nhat Le basin. This approach offers a practical, cost-effective, and near real-time solution for flood response. Implementing this approach can help improve flood damage assessment and mitigate the potential impacts of flood disasters on communities and economies.

A Combined Computational Fluid Dynamics and Thermal–Hydraulic Modeling Approach for Improving the Thermal Performance of Corrugated Tank Transformers: A Comparative Study

In this study, we present a complete analysis of the thermal behavior of an oil-filled distribution transformer using two different approaches: numerically, by applying computational fluid dynamics (CFD) simulations; and analytically, by using thermal–hydraulic modelling (THM). The THM method becomes challenging when the corrugated transformer tank wall structures are complex, and therefore CFD simulations are required to provide in-depth details of the winding oil thermal–hydraulic behavior and to generate parameters for improving the THM calculation. The numerical and analytical thermal performance results were then compared with heat-run measurements of a case study transformer and the accuracy of both approaches on different thermal performance parameters was validated. This study has certain reference value for improving the thermal performance and operation efficiency of distribution transformers, and eventually aims to provide engineers with an effective tool to design the most efficient and reliable distribution transformers with corrugated tank walls for various applications.

Development of a user-friendly hydraulic model for simulating hybrid water distribution networks: a transition toward sector sustainability

Abstract The conventional computational approach for modeling and simulating drinking water distribution networks (WDNs) is time-consuming and prone to human errors. Therefore, this study developed and implemented a hydraulic modeling tool, the ‘Kyema-Net model’, based on the modified Hardy Cross algorithm in Visual Basic, to simulate a hybrid WDN with the inclusion of pipe cost assessment. The model's accuracy was validated by comparing its outputs with those of EPANET 2.2 software. The Kyema-Net model and EPANET 2.2 simulation results were comparable. Considering the WDN case study, the proposed model initialized nodal inflows in proportions of 60 and 40% for any two pipes exiting the node, reducing the computational steps. The model executed three trials to achieve the final solution against four trials for EPANET 2.2. The mean absolute percentage error, coefficient of determination (R2), and root mean square error metrics for flow velocity were ∼0.00%, 1.00, and ∼0.00 m, respectively. The modified resilience index values ranged between 0.30 and 1.09. Implementing the proposed hydraulic modeling tool in designing and/or rehabilitating WDNs demonstrated compliance with numerous social-, economic-, and technological-related Sustainable Development Goals. This would assist various water sector stakeholders in the sustainable planning, operation, and management of WDNS globally.

Coupled hydro‐mechanical pore‐scale modeling of biopore‐coated clods for upscaling soil shrinkage and hydraulic properties

AbstractEarthworms and plant roots are vital for macropore formation and stabilization. The organo‐mineral coating of biopore surfaces also regulates macropore‐matrix mass exchange during preferential flow. The influence of finer‐textured burrow coatings on macroscopic soil properties during shrinkage could potentially be assessed by upscaling pore‐scale hydraulic and mechanical simulations. The aim was to investigate the influence of micro parameters (particle size, stiffness, and bond strength) on macro parameters (i.e., shrinkage curve and soil hydraulic properties). Drainage experiments and simulations were carried out using biopore‐coated clod‐size samples compared to those without coating. Simulations were performed using a two‐phase pore‐scale finite volume coupled with discrete element model (DEM‐2PFV). The structural dynamics was characterized by analyzing the pore volume and soil shrinkage curve obtained from numerically determined data. The soil hydraulic parameters were described using uni‐ and bimodal van Genuchten (vG) functions. The drainage simulations revealed hydro‐mechanical dynamics characterized by Braudeau‐shrinkage curve subdomains: The matrix‐only samples, with lower particle bond strength, exhibited relatively higher shrinkage. The coated samples, with higher particle stiffness and bond strength, displayed greater hydro‐mechanical stability. The numerically determined initial value of the saturated hydraulic conductivity (Ks) was about 70 times larger for matrix‐only samples than for coated samples. As expected, for the nonrigid soil structures, constant Ks, α, and n values for bimodal vG model resulted in prediction errors. Upscaling DEM‐2PFV pore‐scale model outcomes quantifies micro‐coating effects on macro hydro‐mechanics. This yields void ratio‐based soil water retention and hydraulic conductivity functions, advancing macroscopic soil hydraulic models and enhancing structured soil flow and transport descriptions.

Fixed-time adaptive neural control of electro-hydraulic system with model uncertainties: Theory and experiments

Nonlinearities, uncertainties and unknown external loads decline tracking dynamic performance and steady-state accuracy of electro-hydraulic systems. Most existing electro-hydraulic controllers have well guaranteed both the cylinder position and the load pressure asymptotic stable or uniformly ultimately bounded. However, the corresponding output response is relatively slow and achieves the desired performance in an infinite time, which cannot meet the requirements of fast convergence in some engineering applications. In this study, a fixed-time adaptive neural control (FTANC) is proposed for an electro-hydraulic system to improve the fast convergence performance and steady-state accuracy of the cylinder position in case of hydraulic model uncertainties A rigorous theoretical derivation proves that the electro-hydraulic system obtains practically fixed-time stability, such that all system state errors converge to the zero neighborhood in a fixed time without relation to the initial conditions of electro-hydraulic systems. Finally, both the simulation and experimental results verify the effectiveness of the proposed control method.

Flood Risk Mapping during the Extreme February 2021 Flood in the Juruá River, Western Brazilian Amazonia, State of Acre

Cruzeiro do Sul, a municipality in Northwestern Brazil is recurrently impacted by floods, particularly along the Juruá River. This study presents a comprehensive flood risk analysis by integrating geoprocessing, remote sensing, and hydraulic modeling techniques. Our objectives are to simulate flood extents, identify high-risk areas, and guide sustainable territorial management. Our findings illustrate that the flood impacts are distributed across urban (27%), agricultural (55%), and forest/grassland (17%) landscapes. Historical records and literature reviews also underscore a recurring pattern of extreme floods in the municipality, notably during February’s La Niña events. Some vulnerable urban neighborhoods were identified: Vila Cruzeirinho, Centro, Miritizal, and Da Várzea. These areas are especially susceptible due to their proximity to the river and increased surface runoff during high flood events. By amalgamating various data sources and methods, this research aids decision making for flood mitigation and urban development, fostering resilience against recurrent flooding events in Cruzeiro do Sul.

Model-Assisted Muti-source Fusion Hypergraph Convolutional Neural Networks for intelligent few-shot fault diagnosis to Electro-Hydrostatic Actuator

Electro-Hydrostatic Actuator (EHA) is a critical electro-hydraulic actuator system widely used in aerospace equipment. To ensure its normal operation, the intelligent fault diagnosis of the EHA system has gained increasing attention. However, the EHA exhibits strong nonlinearity, high structural complexity, and difficulty obtaining fault samples. A Model-Assisted Multi-source Fusion Hypergraph Convolutional Neural Network (MAMF-HGCN) is proposed to address the few-shot intelligent fault diagnosis of EHA. Specifically, the fault data obtained from the hydraulic simulation model is used to establish the relationship among each channel signal. This assists in constructing a hypergraph structure for actual multi-source fault data under limited samples. Each node in the hypergraph employs message transmission to fuse signals from different channels. Subsequently, the hypergraph data are input into the constructed hypergraph convolutional neural network to perform fault classification. Finally, validating the EHA hydraulic system test rig from Nanjing University of Science and Technology illustrates the method’s effectiveness in diagnosing hydraulic system problems under limited fault samples.

Generalized predictive control application scheme for nonlinear hydro-turbine regulation system: Based on a precise novel control structure

Generalized predictive control (GPC), which has excellent control performance and robustness, is only applicable to the control object that can be expressed in the transfer function and is difficult to be directly applied to hydraulic turbine regulation systems (HTRS) that contain extremely complex nonlinearity. Therefore, considering the practical applications of GPC in a hydropower station containing the Francis turbine, the double models, real-time feedback linearization module, and a nonlinear characteristic compensator are designed, and a generalized predictive control strategy combining these modules (GPC-DM-RFLM-NCC) is proposed. Firstly, the salp swarm algorithm (SSA) is improved based on the chaotic mapping and Levy flight, an accurate nonlinear hydraulic turbine model is constructed based on the backpropagation neural network (BPNN) and improved SSA (ISSA), and an HTRS simulation platform with nonlinear characteristics is built by combining modules such as water diversion system, servo system, and generator. Then, the irrationality of the commonly used linear hydraulic turbine models in HTRS dynamic process simulation is verified through quantitative calculation. Furthermore, by combining the real-time feedback linearization method and ISSA-based nonlinear characteristic compensator, the GPC-DM-RFLM-NCC is proposed. Finally, the HTRS simulation platform, which consists of GPC, double models, real-time feedback linearization module, and nonlinear characteristic compensator, is built, and the applicability, reliability, and excellent robustness of the proposed GPC-DM-RFLM-NCC are verified by the real data of a hydropower station.

Scaled versus real-scale tests: Identifying scale and model errors in wave damping through woody vegetation

Vegetation in front of levees, dikes and seawalls can decrease wave energy and therefore contribute to the safety against flooding. However, wave damping predictions by vegetation are still inaccurate due to measurement and modelling uncertainties. Many studies focused on finding reliable predictive tools using scaled flume tests with vegetation mimics. Scaling down vegetation can however lead to discrepancies with realistic scales, known as scale errors. In this work scaled tests were conducted on 3D-printed elastic replicas of willow trees and compared with real-scale experiments. We identified differences in measured wave dissipation between the scaled hydraulic model (1:10) and its real-scale prototype with 5m high live willow trees under storm conditions (1:1). The maximum measured wave damping (30%) was roughly 1.5 times higher than the real-scale experiments (20%). Following the same trend of the real-scale experiments, this amount of wave height damping declined for larger water levels. Largest effects are argued to be due to increased viscous damping (smaller branch Reynolds numbers) and non-exact flexibility scaling. These significant deviations illustrate that full-scale experiments, although expensive, are still needed to validate the results of scaled experiments for woody vegetation. Alternatively, accounting for these discrepancies can make scaled experiments more reliable and expensive real-scale experiments less needed for wave damping studies on woody vegetation.

Comparative study and validation of a new analytical method for hydraulic modelling of bidirectional low temperature networks

Bidirectional Low Temperature Networks (BLTNs) are an innovative technology of district heating and cooling systems. Because of their intrinsic feature of supplying simultaneous heating and cooling either directly from an energy source/sink or through distributed heat pumps and chillers, circulation pumps installed at each building extract water from the network and a distinct pressure cone is subsequently created. Variations in the amount (and direction) of the extracted water call for accurate hydraulic design and analysis to ensure safe and adequate network operation. This paper proposes a new analytical solution method for fast hydraulic modelling of BLTNs. The analytical method was compared against three numerical solution methods and validated using different current and future operating scenarios of a real-world bidirectional network. In all modelled cases, the calculated mass flows and pressure drops using the new analytical method yielded very small Normalised Mean Bias Error (NMBE) and Coefficient of Variation of the Root Mean Square Error (CV(RMSE)), suggesting excellent agreement between the analytical and numerical solution methods. The new analytical method offers better performance over its numerical counterparts due to its explicit nature, ease of implementation, and quick modelling time.

Flood Risk Assessment of the Middle Reach of the Helmand River, Afghanistan

The middle reach of the Helmand River is prone to floods, and flood hazard analysis is necessary to manage the flood risk. As the study site is a less-developed basin where available geographical and hydrological data are limited, we must utilize available limited data to conduct the flood hazard analysis. A frequency analysis of the annual peak flow rate was performed using available hydrological data for making representative flood hydrographs. A land-use map is derived by classifying recent Landsat images. Digital elevation model derived by Advanced Land Observing Satellite, roughness coefficient correlated with the land-use map, and the representative flood hydrographs are fed into hydraulic model HEC-RAS 2D. Flood inundation area, depth, and velocity for different flood return periods are estimated. Based on local hazard intensity and vulnerability, risk maps for evacuation and vulnerability of crops on the floodplain are obtained. Spatial flood risk characteristics differ at the upstream and downstream reaches because of distinct floodplain topography. Flood countermeasures for each reach are proposed based on the spatial characteristics of the flood risk. To provide risk information for residents within the region, the flood hazard, risk, and damage maps derived in this study are published as a web map application and a mobile native application.

Numerical Modeling of Potential Large Wood Entrainment in Rivers: Application of Hybrid Modeling in the Inter‐Dam Reach of the Dyje River, Czechia

AbstractMobilization of large wood in river channels during floods represents a hazardous factor, augmenting flood risk and endangering infrastructures such as bridges, weirs, and reservoir dams. A hybrid modeling approach combining numerical models with field‐based surveys has been recently used to elucidate the processes of LW entrainment and deposition in rivers. We used two‐dimensional hydraulic modeling performed in HEC‐RAS to simulate LW entrainment in two valley bottom segments of the Dyje River, Czechia, where LW deposition is a significant hazard to the dam of the downstream Znojmo reservoir. We surveyed all LW pieces in the inundation area of the 2002 extreme (>Q100) flood and simulated their entrainment for eight flood scenarios (1–100‐year recurrence interval). We used the equations of Braudrick and Grant (2000, https://doi.org/10.1029/1999WR900290) to calculate the LW entrainment threshold; we introduced coefficient k accounting for the incomplete submersion of LW pieces resting on an inclined surface into the original equations. Four entrainment categories — stable, wetted stable, wetted buoyant, and wetted entrained — were defined, and the proportion of LW pieces in each category was calculated for the flood scenarios. We found marked differences in entrainment categories for respective flood scenarios between the two valley segments. These were attributed to the differences in pieces' dimensions, their spatial distribution within the inundation area, and valley‐bottom topography, which affects the hydraulic conditions for a given discharge. The presented approach enables the calculation of the LW quantity potentially mobilized by the flood of a certain magnitude indicating the degree of potential risk for the infrastructures located downstream.

Influence of Partition Wall Length on Inlet Flow Regime of a Pumping Station Arranged in Parallel with a Sluice Gate

When a sluice gate is arranged in parallel with pumping station units, biased flow occurs in the forebay when the units are operating. The transverse flow velocity in front of the channel inlet is relatively high, and, in severe cases, it may lead to the formation of suction vortices, impacting the stable operation of pump units. Taking the Liushan Pumping Station project of the Eastern Route of the South-to-North Water Diversion Project as a case study, this paper investigates the effect of the partition wall length on the inlet flow regime of pumping station units arranged in parallel with the sluice gate to reduce the transverse flow velocity in front of the channel inlet. Using numerical simulations, the inlet flow regimes for different partition wall lengths were compared. Moreover, the flow field distributions in the forebay under different operating conditions were analyzed alongside the transverse flow velocity in front of the channel inlet and the uniformity of flow velocity distribution in the section behind the channel inlet. Hydraulic model tests were then conducted to validate the simulation results. The results indicate that in the original design, there existed a vortex zone in the forebay in front of the inlet of the channel where the transverse flow was relatively high. However, the introduction of partition walls significantly reduced the transverse flow velocity in front of the inlet of the channel in the forebay. The optimal effect was achieved when the length of the partition wall was twice the width of the inlet channel. Furthermore, the uniformity of velocity distribution at the inlet of the channel increased by an average of 7.4%, leading to a substantial improvement in the inlet flow regime of the pumping station. The addition of partition walls in the forebay effectively resolved the issues related to the flow regime in the forebay, providing valuable references for similar engineering studies in the future.

Analysis of the Impact of Hydraulic Gates on a Stabilized Tidal Inlet Structure: Mathematical Model and Data Measurements

Tidal inlet structures are engineering projects with associated benefits related to flood control, water quality enhancement, and coastal protection. This study analyzes the performance of hydraulic gates on a stabilized inlet in estuarine systems by developing a simplified hydraulic model that considers inlet and outlet water levels. The proposed model was applied to the stabilized tidal inlet structure in Cartagena de Indias, Colombia. This model offers a practical tool for engineers and designers operating estuarine systems. The analysis focuses on the coastal lagoon of Ciénaga de la Virgen. The proposed model was successfully calibrated using two water sensors, with extreme input and outlet flow rates of approximately 260 m3/s and 110 m3/s, respectively. The average daily output volume in the system is 3,361,000 m3, while the average daily input volume is 3,200,000 m3. Consequently, the manipulation of the opening gates results in a decrease in the estuarine water level, potentially by as much as 25 cm, which local authorities can use to make decisions to reduce extreme water levels during flooding events.

Seepage propagation simulation of a tunnel gasketed joint using the cohesive zone model

The gasketed joint plays a critical role in the waterproof or water-leakage resistance performance of tunnel segmental linings. This study presents a novel numerical simulation method based on the cohesive zone model (CZM) to accurately analyze the seepage phenomena along the interface of elastic sealing gaskets in shield tunnel joints. While traditional finite element methods are widely used, they cannot simulate interface opening, limiting their applicability. To overcome this challenge, the proposed method leverages the concept of hydraulic fracturing and redefines the seepage problem as a seepage problem of elastic impermeable media. By establishing a two-dimensional hydraulic fracturing model using the CZM, this study conducts a comprehensive sensitivity analysis of the cohesive element parameters and validates the accuracy and effectiveness of simulating seepage along the interface of elastic impermeable media. Based on the insights gained from the sensitivity analysis, a seepage calculation model is successfully developed, considering the unique characteristics of elastic sealing gaskets. The model is applied to three cross-sectional shapes of elastic sealing gaskets, and their seepage characteristics are analyzed based on the interface opening displacement and liquid pressure distributions during seepage. The results highlight the SC3 cross-sectional shape, which exhibits minimal opening displacement and the highest net water pressure at the moment of seepage occurrence, demonstrating superior waterproof performance compared to other forms. Through the introduction of the CZM, comprehensive parameter analysis, validation, and practical application, this study overcomes the limitations of traditional finite element methods in simulating interface opening. The proposed model, which more accurately captures seepage characteristics than other methods, provides an optimized simulation method for analyzing hydraulic coupling issues related to seepage at shield tunnel joints and is a significant contribution to the field, enhancing our understanding and enabling more accurate analyses of seepage phenomena in shield tunnel joints using elastic sealing gaskets.

Fast urban inundation simulation with RIM2D for flood risk assessment and forecasting

IntroductionUrban pluvial flooding is a growing concern worldwide as consequence of rising urban population and climate change induced increases in heavy rainfall. Easy-to-implement and fast simulation tools are needed to cope with this challenge.MethodsThis study describes the development of the parsimonious, GPU-accelerated hydraulic model RIM2D for urban pluvial flood simulations. This is achieved by considering the built-up urban area as flow obstacles, and by introducing capacity-based approaches to consider urban drainage by infiltration on pervious surfaces and sewer drainage from roofs and sealed surfaces. The model performance was analyzed by simulating 8 heavy rainfall events in a test area in the city of Dresden, Germany. For these events detailed discharge measurements of sewer discharge are available, providing a unique dataset for evaluating the sewer drainage simulation, which is of high importance for realistic pluvial inundation simulations in urban areas.Results and discussionWe show that the model simulates the temporal dynamics of the sewer discharge and the sewer volume within acceptable ranges. Moreover, the erratic variation of the simulated to measured sewer discharge suggests that the deviations from the measurements are caused by the precipitation input rather than the model simplifications. We conclude that RIM2D is a valid tool for urban inundation simulation. Its short simulation runtimes allow probabilistic flood risk assessments and operational flood forecasts.