{"title":"Three-dimensional numerical modelling of floods in river corridor with complex vegetation quantified using airborne LiDAR imagery","authors":"Keisuke Yoshida, Y. Kajikawa, Satoshi Nishiyama, Md. Touhidul Islam, Shin Adachi, Koichi Sakai","doi":"10.1080/00221686.2022.2106596","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106596","url":null,"abstract":"Excessive flood flow over the historic diversion weir in the vegetated Asahi River in Okayama Prefecture, Japan, was recently recorded for the first time after its renovation work. Fluvial researchers analysed the diversion discharge for flood mitigation measures through laboratory studies and conventional two-dimensional (2-D) depth-averaged simulations. The existing model was insufficient for simulation of certain phenomena such as flow resistance caused by vegetation branches and leaves and vertical flow distribution around the river corridor. Therefore, we developed a three-dimensional (3-D) vegetation resistance porous model by estimating topography, land cover, and vegetation distribution from airborne light detection and ranging (LiDAR) topo-bathymetry (ALB) data. Results show that the water level and flow regime were more reproducible than by referenced 2-D calculations when compared to space-time image velocimetry (STIV) data and field measurements. The diversion discharge designed using the proposed model is feasible with the current riverbed and vegetation conditions.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42477902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Air–water flow in a plain stilling basin below smooth and stepped chutes","authors":"I. Stojnic, M. Pfister, J. Matos, A. Schleiss","doi":"10.1080/00221686.2022.2106593","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106593","url":null,"abstract":"In recent decades, stepped chutes followed by a stilling basin became a standard for spillways of dams. The comprehensive knowledge of stepped chute approach flows on internal air–water flow properties of the hydraulic jump is still too limited for an appropriate design of stilling basins. Therefore, an experimental campaign was performed on a large-scale physical model of a plain stilling basin preceded by a 30° sloping smooth or stepped chute. Stepped chute approach flows induce lower deaeration rates along the jump roller as compared to smooth chute approach flows, indicating longer dimensionless jump lengths, normalized by the tailwater depth. Pronounced bottom air concentrations were observed within the first 40% of the jump length in the stilling basin downstream of the stepped chute. Thus, despite the significantly higher pressure fluctuations, this zone seems better protected against cavitation damage than in stilling basins following a smooth chute.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46068088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the equations of open channel flow","authors":"William Guerin Gray, Cass Timothy Miller","doi":"10.1080/00221686.2022.2106597","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106597","url":null,"abstract":"The traditional equations for describing open channel flow have appeared in the literature for decades and are so ingrained that they might seem to be statements of settled science. Careful derivations that detail assumptions and approximations relied upon in the formulation are mostly absent. We derive mass, momentum, and energy equations by averaging their small-scale counterparts and formulate forms that are Galilean invariant as required by continuum mechanics. Averaging is over a time increment and a spatial region in a single step, clarifying the need for closure relations. The derivation leads to the Boussinesq tensor and Coriolis vector as rigorous generalizations of the Boussinesq and Coriolis coefficients typically proposed. Examples are provided for the computation of these coefficients from published data. The approach employed here can be extended to systems such as pipe flow or shallow water equations, and the Galilean invariant forms are also suitable for entropy generation analyses.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45040399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Global linear stability analysis of flow inside an axial swirl generator with a rotating vortex rope","authors":"Z. Seifi, M. Raisee, M. Cervantes","doi":"10.1080/00221686.2022.2106591","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106591","url":null,"abstract":"In hydraulic turbines, either Francis or axial turbines, a high swirling flow is generated at PL conditions at the inlet of the draft tube resulting in the formation of a rotating vortex rope (RVR). This leads to pressure fluctuations which limit the operating range of single regulated turbines. In the present study, an axial hydraulic turbine has been numerically simulated by the and SST-based Scale-Adaptive Simulation model (SST SAS) turbulent models to capture helical RVR. Considering the formation of the RVR as the result of a global instability, linear global stability analysis of the time-averaged turbulent flow field has been conducted. For the first time in axial hydraulic turbines, how boundary conditions affect the unstable mode and which frequency, plunging or rotating, is related to the vortex rope instability have been studied. It is found that the flow inside the draft tube is sensitive to the asymmetrical disturbances with a frequency close to the rotational component.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44141580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Self-similar solutions of shallow water equations with porosity","authors":"V. Guinot, C. Delenne, S. Soares-Frazão","doi":"10.1080/00221686.2022.2106598","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106598","url":null,"abstract":"Simulated free surface transients in periodic urban layouts have been reported to be self-similar in the space-time domain when averaged on the scale of the building period. Such self-similarity is incompatible with the head loss model formulae used in most porosity-based shallow water models. Verifying it experimentally is thus of salient importance. New dam-break flow laboratory experiments are reported, where two different configurations of idealized periodic buildings layouts are explored. A space-time analysis of the experimental water level fields validates the self-similar character of the flow. Simulating the experiment using the two-dimensional shallow water model also yields self-similar period-averaged flow solutions. Then, the Single Porosity (SP), Integral Porosity (IP) and Dual Integral Porosity (DIP) models are applied. Although all three models behave in a similar fashion when the storage and connectivity porosities are close to each other, the DIP model is the one that upscales best the refined 2D solution.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47332815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transport equation for nonuniform suspended sediment","authors":"B. Jia, Lei Zhang, D. Zhong","doi":"10.1080/00221686.2022.2106594","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106594","url":null,"abstract":"Theoretical research on nonuniform sediment suspension is limited due to difficulties of elucidating nonuniform particle interaction. A new transport equation is generalized for nonuniform suspended sediment based on multi-dispersed two-phase flow theory, to account for nonuniform particle interaction and its effect on sediment suspension. Instead of implementing numerical discretization, constitutive relation of drift velocity is derived by solving the momentum equations with the aid of the Sherman–Morrison–Woodbury formula and the perturbation asymptotic technique. Applied to open channel flows, concentration profiles for each grain size of sediment are derived and a satisfactory consistency is obtained in comparison with both experimental and field data. Nonuniform sediment suspension is attributed to fluid turbulence, gravity, particle inertia and nonuniform particle interaction. The nonuniform effect plays an important role in the vicinity of the riverbed and is positively correlated to sediment concentration and grain size ratios, which helps bring insight into the suspension mechanics.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43260340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sensitivity analysis of a three-dimensional simulation of turbidity currents in a sloping flume","authors":"Ruoyin Zhang, Baosheng Wu, Bangwen Zhang","doi":"10.1080/00221686.2022.2106590","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106590","url":null,"abstract":"Sensitivity analysis is necessary in numerical models to establish the optimal model configuration and simulate turbidity currents accurately. The sensitivity of turbidity currents simulated by a three-dimensional numerical model named the semi-implicit cross-scale hydroscience integrated system model (SCHISM) was assessed using domain discretization, the turbulence closure model, and the transport scheme. The results show that a higher horizontal resolution with an appropriate aspect ratio, localized sigma coordinates with shaved cells (LSC2) grid with sufficient layers, a two-phase mixture turbulence closure model, and transport schemes with critical depth ratio lower than 1 could improve the model performance on the turbidity currents. The study can provide helpful guidance to establish accurate turbidity current simulations in complex water environments.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47408810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical modelling of local scour around a spur dike with porous media method","authors":"Xun Han, P. Lin, G. Parker","doi":"10.1080/00221686.2022.2106589","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106589","url":null,"abstract":"ABSTRACT A 3D numerical model is developed to investigate the flow motion and sediment transport around a spur dike. In this model, fluid motion is described by the Navier–Stokes equations, adopting large eddy simulation to capture turbulent transport and dissipation. The spur dike and sand bed are treated by the porous media method. The suspended load concentration and the bed load transport rate is calculated separately, and then the bed variation is updated using the mass-balance equation. A series of flume experiments are employed to validate the model’s performance before being applied for the case of partially emergent spur dikes and submerged spur dikes, respectively. Detailed analyses on the spatial-temporal variation of flow intensity, sediment concentration and shapes of scour holes are made, based on which some innovative findings are discussed such as the scouring process patterns, as well as the influence of flow conditions on the maximum scour depth and location, and then useful engineering suggestions are provided to improve structural safety.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44852664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongxin Guo, Xinlei Guo, Yisen Wang, Tao Wang, Hui Fu, Jiazhen Li
{"title":"Closure to “Flow condition identification and discharge calibration for submerged radial gates” by YONGXIN GUO, XINLEI GUO, YISEN WANG, TAO WANG, HUI FU and JIAZHEN LI, J. Hydraulic Res. 59(4), 2021, 683–690 https://doi.org.10.1080/00221686.2020.1818305.","authors":"Yongxin Guo, Xinlei Guo, Yisen Wang, Tao Wang, Hui Fu, Jiazhen Li","doi":"10.1080/00221686.2022.2106595","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106595","url":null,"abstract":"The Authors appreciate the Discussers for their interest in the work and the concerns they raised. Discharge calibration for gates is certainly a research area that merits a great deal of attention in order to improve discharge measurement and automatic control. Considering the Discussers’ suggestions, the Authors reanalysed the discharge errors predicted by Wingate software using the Buyalski’s (1983) experimental data with hard rubber bar seals. The following conclusions can be drawn:","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44343476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanbin Yang, S. Hou, Wanli Yang, Sijing Li, Hailin Hou, Qiao Li
{"title":"Experimental investigation of current forces on a square caisson with small aspect ratios during the sinking process","authors":"Hanbin Yang, S. Hou, Wanli Yang, Sijing Li, Hailin Hou, Qiao Li","doi":"10.1080/00221686.2022.2106588","DOIUrl":"https://doi.org/10.1080/00221686.2022.2106588","url":null,"abstract":"ABSTRACT The study of flow around a square caisson considering the combined effects of free surface, free end and bottom boundary is limited. Experiments were performed in this study to investigate the characteristics of current forces on a square caisson model considering the combined effects of free surface, free end and bottom boundary. Results show that the drag coefficient and the root mean square coefficient of transverse force generally increase with aspect ratio (AR), and significantly increase at the instant when the free end disappears. The bottom boundary decreases the values of root mean square coefficients of drag force and vertical force. The drag coefficient decreases with incident angle ( ) when , but increases with when . The trim and squat phenomenon caused by shallow water effect when the caisson is nearly touching the riverbed (seabed) during the sinking process should receive extra attention in practice.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59083116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}