Pub Date : 2023-07-04DOI: 10.1080/00221686.2023.2231396
Yang Xiao, Kang Yuan, Taotao Zhang, Jian Zhou
The prediction of the velocity distribution in adverse-slope flow is improved by analytical and experimental study of the wake and dip effects, based on the log-wake-dip velocity law. This improved equation allows accurate prediction of the wake phenomenon and dip phenomenon. The equation compares very well with the experimental data obtained in the present study and some reference data, and it predicts better than other formulations available in the literature. This study shows that the wake-parameter can be expressed by the linear equation for the pressure-gradient parameter, under the conditions of the respective Reynolds number and aspect ratio. The dip-parameter can be determined as constants using the known position of the maximum velocity point. When the pressure gradient is relatively small, the wake effect is a boost to velocity. In contrast, when the pressure gradient is relatively large, the wake effect is an impediment to velocity.
{"title":"Analytical and experimental study of velocity distribution in adverse-slope channel flow","authors":"Yang Xiao, Kang Yuan, Taotao Zhang, Jian Zhou","doi":"10.1080/00221686.2023.2231396","DOIUrl":"https://doi.org/10.1080/00221686.2023.2231396","url":null,"abstract":"The prediction of the velocity distribution in adverse-slope flow is improved by analytical and experimental study of the wake and dip effects, based on the log-wake-dip velocity law. This improved equation allows accurate prediction of the wake phenomenon and dip phenomenon. The equation compares very well with the experimental data obtained in the present study and some reference data, and it predicts better than other formulations available in the literature. This study shows that the wake-parameter can be expressed by the linear equation for the pressure-gradient parameter, under the conditions of the respective Reynolds number and aspect ratio. The dip-parameter can be determined as constants using the known position of the maximum velocity point. When the pressure gradient is relatively small, the wake effect is a boost to velocity. In contrast, when the pressure gradient is relatively large, the wake effect is an impediment to velocity.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"437 - 451"},"PeriodicalIF":2.3,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48395583","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}
Pub Date : 2023-07-04DOI: 10.1080/00221686.2023.2232784
Panchali Chakraborty, A. K. Barbhuiya
The present laboratory study is done to understand the effect of suction seepage flow on the scour geometry around an abutment placed on non-cohesive bed materials. The experimental data revealed that suction seepage through the channel side and bed affects the scour depth and deposition height. Under the present experimental conditions, it is found that the maximum reduction of scour depth under vertical suction, side suction and combined suction are 37%, 19% and 21% respectively. The results further demonstrate that the reduction of scour depth at the upstream outer nose of the abutment is more under vertical suction, whereas under side suction, the main influence area is closer to the side wall. However, under combined suction seepage, it is found that the reduction of scour depth is in between vertical suction seepage and side suction seepage. Another important finding is that scour reduction increases with increase in seepage rate.
{"title":"Local scour at abutment under vertical and side suction seepage","authors":"Panchali Chakraborty, A. K. Barbhuiya","doi":"10.1080/00221686.2023.2232784","DOIUrl":"https://doi.org/10.1080/00221686.2023.2232784","url":null,"abstract":"The present laboratory study is done to understand the effect of suction seepage flow on the scour geometry around an abutment placed on non-cohesive bed materials. The experimental data revealed that suction seepage through the channel side and bed affects the scour depth and deposition height. Under the present experimental conditions, it is found that the maximum reduction of scour depth under vertical suction, side suction and combined suction are 37%, 19% and 21% respectively. The results further demonstrate that the reduction of scour depth at the upstream outer nose of the abutment is more under vertical suction, whereas under side suction, the main influence area is closer to the side wall. However, under combined suction seepage, it is found that the reduction of scour depth is in between vertical suction seepage and side suction seepage. Another important finding is that scour reduction increases with increase in seepage rate.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"592 - 600"},"PeriodicalIF":2.3,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46479578","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2222276
Yesheng Lu, N. Cheng, M. Wei, Ai-Min Luo
The scour induced by wall jets may cause serious bed erosion and thus damage to hydraulic structures. Previous studies are largely empirical, providing only correlations of experimental data. At present, it is not clear what difference exists in the physical mechanisms of two-dimensional (2D) and three-dimensional (3D) wall jet scour. This study first summarizes previous efforts for predicting wall jet scour depths. Then, a scaling analysis is presented for investigating scour depths by applying the phenomenological theory of turbulence. It is shown that for wall jet cases, the dimensionless equilibrium scour depth can generally be expressed as a power function of the densimetric Froude number and relative roughness height, with the power index depending on jet configurations. The predictions of scour depth using the resulting formulas agree well with published data. The present analysis provides new insights into the understanding of the underlying physical mechanisms of wall jet scour as well as the difference between 2D and 3D configurations.
{"title":"Scaling laws for two- and three-dimensional wall jet scour based on the phenomenological theory of turbulence","authors":"Yesheng Lu, N. Cheng, M. Wei, Ai-Min Luo","doi":"10.1080/00221686.2023.2222276","DOIUrl":"https://doi.org/10.1080/00221686.2023.2222276","url":null,"abstract":"The scour induced by wall jets may cause serious bed erosion and thus damage to hydraulic structures. Previous studies are largely empirical, providing only correlations of experimental data. At present, it is not clear what difference exists in the physical mechanisms of two-dimensional (2D) and three-dimensional (3D) wall jet scour. This study first summarizes previous efforts for predicting wall jet scour depths. Then, a scaling analysis is presented for investigating scour depths by applying the phenomenological theory of turbulence. It is shown that for wall jet cases, the dimensionless equilibrium scour depth can generally be expressed as a power function of the densimetric Froude number and relative roughness height, with the power index depending on jet configurations. The predictions of scour depth using the resulting formulas agree well with published data. The present analysis provides new insights into the understanding of the underlying physical mechanisms of wall jet scour as well as the difference between 2D and 3D configurations.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"422 - 430"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43949124","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2201357
Xun Han, Wang-ru Wei, P. Lin, Jun Deng, Wei-lin Xu
The phenomenon of a water droplet impact on a free surface is studied to understand the physics of free surface bubble entrainment. Particle image velocimetry (PIV) and high-speed image system are used to analyse the flow structure evolutions in the droplet impact cavity period and bubble entrainment cavity period, respectively. The photographic results show that the entrapped surface of the impact cavity remains intact and continuous, and individual bubble entrainment occurs during the secondary entrainment cavity evolution. The instantaneous distributions of velocity fields in the longitudinal and lateral directions are uniform and independent of the approaching impact velocity. For the entrainment cavity evolution, the transverse diffusion intensity is higher than that for the impact cavity period. An individual bubble forms during the transverse velocity penetration across the droplet impact area. Consequently, for the droplet impact on a water surface, the present study implies the presence of a mechanism by which the interior flow field plays a key role in the bubble entrainment.
{"title":"Experimental study on flow fields and bubble entrainments by the water droplet impact using 3D PIV tests","authors":"Xun Han, Wang-ru Wei, P. Lin, Jun Deng, Wei-lin Xu","doi":"10.1080/00221686.2023.2201357","DOIUrl":"https://doi.org/10.1080/00221686.2023.2201357","url":null,"abstract":"The phenomenon of a water droplet impact on a free surface is studied to understand the physics of free surface bubble entrainment. Particle image velocimetry (PIV) and high-speed image system are used to analyse the flow structure evolutions in the droplet impact cavity period and bubble entrainment cavity period, respectively. The photographic results show that the entrapped surface of the impact cavity remains intact and continuous, and individual bubble entrainment occurs during the secondary entrainment cavity evolution. The instantaneous distributions of velocity fields in the longitudinal and lateral directions are uniform and independent of the approaching impact velocity. For the entrainment cavity evolution, the transverse diffusion intensity is higher than that for the impact cavity period. An individual bubble forms during the transverse velocity penetration across the droplet impact area. Consequently, for the droplet impact on a water surface, the present study implies the presence of a mechanism by which the interior flow field plays a key role in the bubble entrainment.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"396 - 408"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46237471","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2201210
Alireza Shamkhalchian, Gustavo A. M. De Almeida
This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accurate in space (i.e. piecewise linear reconstruction of variables) Godunov-type finite volume (FV) method, while the fine mesh is used to incorporate high-resolution topography and roughness into the solution. The accuracy and performance of the model were compared against a first-order version of the model recently proposed by the authors and a second-order conventional FV model using artificial and real-world test problems. Results showed that improved accuracy is delivered by the proposed model, and that at low-resolution meshes, the spatial reconstruction of variables of the numerical scheme plays a major role in the solution's accuracy.
{"title":"Effects of reconstruction of variables on the accuracy and computational performance of upscaling solutions of the shallow water equations","authors":"Alireza Shamkhalchian, Gustavo A. M. De Almeida","doi":"10.1080/00221686.2023.2201210","DOIUrl":"https://doi.org/10.1080/00221686.2023.2201210","url":null,"abstract":"This paper presents a new sub-grid flood inundation model obtained by upscaling the shallow water equations (SWE) to enhance the model efficiency in large-scale problems. The model discretizes study domains using two nested meshes. The equations are solved at the coarse mesh by a second-order accurate in space (i.e. piecewise linear reconstruction of variables) Godunov-type finite volume (FV) method, while the fine mesh is used to incorporate high-resolution topography and roughness into the solution. The accuracy and performance of the model were compared against a first-order version of the model recently proposed by the authors and a second-order conventional FV model using artificial and real-world test problems. Results showed that improved accuracy is delivered by the proposed model, and that at low-resolution meshes, the spatial reconstruction of variables of the numerical scheme plays a major role in the solution's accuracy.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"409 - 421"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49607721","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2207525
Yong Peng, Haichuan Du, Bo Wang
In the present study, a boundary treatment scheme named the partially saturated method (PSM) is incorporated into the discrete Boltzmann model (DBM) for shallow water flows to deal with complex curved boundaries. In this PSM-DBM, the two-dimensional 16 velocity levels scheme is adopted and the finite difference method is used to solve the governing equation. Then, the PSM-DBM has been applied to simulate four cases, i.e. such as steady flow in a bending channel, the flow past a stationary cylinder, a jet-forced flow in a circular basin and flow in a meandering channel with 90° consecutive bends. The simulated results have been compared with the experiments and the simulation by traditional numerical simulation. The study shows that the agreement between simulation and experiments is good. It is demonstrated that the PSM-DBM is stable and accurate to deal with the curved boundaries. Moreover, the implementation of the PSM is relatively straightforward in treating stationary curved geometries and is easy to be incorporated into the DBM for shallow water flows. In conclusion, the proposed PSM-DBM can be used widely for flows with curved boundaries.
{"title":"A curved boundary treatment for discrete Boltzmann model of shallow water flows based on a partially saturated method","authors":"Yong Peng, Haichuan Du, Bo Wang","doi":"10.1080/00221686.2023.2207525","DOIUrl":"https://doi.org/10.1080/00221686.2023.2207525","url":null,"abstract":"In the present study, a boundary treatment scheme named the partially saturated method (PSM) is incorporated into the discrete Boltzmann model (DBM) for shallow water flows to deal with complex curved boundaries. In this PSM-DBM, the two-dimensional 16 velocity levels scheme is adopted and the finite difference method is used to solve the governing equation. Then, the PSM-DBM has been applied to simulate four cases, i.e. such as steady flow in a bending channel, the flow past a stationary cylinder, a jet-forced flow in a circular basin and flow in a meandering channel with 90° consecutive bends. The simulated results have been compared with the experiments and the simulation by traditional numerical simulation. The study shows that the agreement between simulation and experiments is good. It is demonstrated that the PSM-DBM is stable and accurate to deal with the curved boundaries. Moreover, the implementation of the PSM is relatively straightforward in treating stationary curved geometries and is easy to be incorporated into the DBM for shallow water flows. In conclusion, the proposed PSM-DBM can be used widely for flows with curved boundaries.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"346 - 355"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44998132","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2202661
P. Hu, Aofei Ji, Wei Li, Z. Cao
A new slope-failure operator for bank sediment collapsing is proposed and tested. As compared to traditional operators that mainly depend on geometric parameters, the new operator considers the fact that collapsed sediments should firstly enter into the nearby water flow, and whether the collapsed sediments become part of the nearby bed should depend on the local flow and sediment conditions. Both the improved and traditional operators are implemented into the hydro-sediment-morphodynamic modelling framework. The model with these operators is applied to simulate experimental levee-breaching processes induced by overtopping flows. The model with the improved operator can produce numerical solutions (e.g. breaching shape, discharge) of much better accuracy (e.g. the RMSE for breaching discharge is 0.0024–0.0058 m³ s−1), as compared to the using of the traditional operator (e.g. the RMSE for breaching discharge is 0.0033–0.0087 m³ s−1).
{"title":"Numerical modelling of levee breach with an improved slope-failure operator","authors":"P. Hu, Aofei Ji, Wei Li, Z. Cao","doi":"10.1080/00221686.2023.2202661","DOIUrl":"https://doi.org/10.1080/00221686.2023.2202661","url":null,"abstract":"A new slope-failure operator for bank sediment collapsing is proposed and tested. As compared to traditional operators that mainly depend on geometric parameters, the new operator considers the fact that collapsed sediments should firstly enter into the nearby water flow, and whether the collapsed sediments become part of the nearby bed should depend on the local flow and sediment conditions. Both the improved and traditional operators are implemented into the hydro-sediment-morphodynamic modelling framework. The model with these operators is applied to simulate experimental levee-breaching processes induced by overtopping flows. The model with the improved operator can produce numerical solutions (e.g. breaching shape, discharge) of much better accuracy (e.g. the RMSE for breaching discharge is 0.0024–0.0058 m³ s−1), as compared to the using of the traditional operator (e.g. the RMSE for breaching discharge is 0.0033–0.0087 m³ s−1).","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"333 - 345"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41938421","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2209879
Wen Zhang, Ruihua Nie, B. Melville, Colin N. Whittaker, A. Shamseldin, Xing-nian Liu, Lu Wang
Rock weirs are low-head river restoration structures. The present study comprised two sets of flume tests (i.e. fixed bed and moveable sand bed tests) to investigate the rock dislodgement process, which is a primary cause of the failure of rock weirs. The impacts of approach flow intensity, submergence, void ratio and scour of bed sediment on rock weir dislodgement, and the responses of sediment bed scour at rock weirs to the rock weir dislodgement, are analysed and discussed. Three limits are defined to classify the amount of the rock weir dislodgement: (1) limit I indicates the incipient dislodgement of rock from downstream weir toe; (2) limit II indicates that a few rocks are dislodged from downstream weir face and weir crest; (3) limit III indicates that large numbers of rocks are dislodged from downstream weir face and weir crest, which leads to weir failure. A predictor of each limit is proposed for rock weir design.
{"title":"Failure of rock weirs due to rock dislodgements","authors":"Wen Zhang, Ruihua Nie, B. Melville, Colin N. Whittaker, A. Shamseldin, Xing-nian Liu, Lu Wang","doi":"10.1080/00221686.2023.2209879","DOIUrl":"https://doi.org/10.1080/00221686.2023.2209879","url":null,"abstract":"Rock weirs are low-head river restoration structures. The present study comprised two sets of flume tests (i.e. fixed bed and moveable sand bed tests) to investigate the rock dislodgement process, which is a primary cause of the failure of rock weirs. The impacts of approach flow intensity, submergence, void ratio and scour of bed sediment on rock weir dislodgement, and the responses of sediment bed scour at rock weirs to the rock weir dislodgement, are analysed and discussed. Three limits are defined to classify the amount of the rock weir dislodgement: (1) limit I indicates the incipient dislodgement of rock from downstream weir toe; (2) limit II indicates that a few rocks are dislodged from downstream weir face and weir crest; (3) limit III indicates that large numbers of rocks are dislodged from downstream weir face and weir crest, which leads to weir failure. A predictor of each limit is proposed for rock weir design.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"356 - 368"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44555581","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2222094
V. Papaioannou, P. Prinos
Natural convection induced by surface cooling in sloping water bodies with vegetation is investigated numerically. The sloping water body consists of a vegetated region with a bottom slope equal to 0.1 and a deep region with a horizontal bottom. The volume-averaged Navier–Stokes equations together with the volume-averaged energy equation are solved numerically in the vegetated region. Submerged vegetation has an equivalent porosity of 0.85. The vegetation length is either equal to the total or half the sloping region. A differential cooling is applied at the top free surface with a varying heat loss rate between the two regions. The non-vegetated sloping water body is also considered for validation purposes. The results indicate that, when cooling is reduced in the vegetated region (a) there is a time delay for the establishment of the quasi-steady regime and (b) the exchange flow rate and the gravity current's velocity decreases with increasing vegetation length. When cooling is completely blocked, different circulation patterns are developed.
{"title":"Natural convection due to surface cooling in sloping water bodies with vegetation","authors":"V. Papaioannou, P. Prinos","doi":"10.1080/00221686.2023.2222094","DOIUrl":"https://doi.org/10.1080/00221686.2023.2222094","url":null,"abstract":"Natural convection induced by surface cooling in sloping water bodies with vegetation is investigated numerically. The sloping water body consists of a vegetated region with a bottom slope equal to 0.1 and a deep region with a horizontal bottom. The volume-averaged Navier–Stokes equations together with the volume-averaged energy equation are solved numerically in the vegetated region. Submerged vegetation has an equivalent porosity of 0.85. The vegetation length is either equal to the total or half the sloping region. A differential cooling is applied at the top free surface with a varying heat loss rate between the two regions. The non-vegetated sloping water body is also considered for validation purposes. The results indicate that, when cooling is reduced in the vegetated region (a) there is a time delay for the establishment of the quasi-steady regime and (b) the exchange flow rate and the gravity current's velocity decreases with increasing vegetation length. When cooling is completely blocked, different circulation patterns are developed.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"382 - 395"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48092177","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}
Pub Date : 2023-05-04DOI: 10.1080/00221686.2023.2201340
Sixue Cheng, Hai-jiang Liu
In this study, a speed parameter is introduced into the steady Korteweg–de Vries (KdV)–Burgers equation which enables the theoretical undular bore profiles to be adjustable with a proper combination of the speed parameter and the viscous damping parameter. A new criterion for identifying the above two bores is then proposed with respect to these two parameters, whose influence on the undular bore profile is then discussed. For the theoretical solution with a small damping, error after introducing the variable speed parameter is limited. A large speed parameter corresponds to a wide range of acceptable dampings. From the energy perspective, it is confirmed that the speed parameter also denotes the nonlinearity effect. In addition, comparison between the theoretical and experimental results shows the superiority of the present model over the traditional model, which also reveals the physical meanings of the present model.
{"title":"On adjustable undular bore profiles based on the modified steady KdV–Burgers equation","authors":"Sixue Cheng, Hai-jiang Liu","doi":"10.1080/00221686.2023.2201340","DOIUrl":"https://doi.org/10.1080/00221686.2023.2201340","url":null,"abstract":"In this study, a speed parameter is introduced into the steady Korteweg–de Vries (KdV)–Burgers equation which enables the theoretical undular bore profiles to be adjustable with a proper combination of the speed parameter and the viscous damping parameter. A new criterion for identifying the above two bores is then proposed with respect to these two parameters, whose influence on the undular bore profile is then discussed. For the theoretical solution with a small damping, error after introducing the variable speed parameter is limited. A large speed parameter corresponds to a wide range of acceptable dampings. From the energy perspective, it is confirmed that the speed parameter also denotes the nonlinearity effect. In addition, comparison between the theoretical and experimental results shows the superiority of the present model over the traditional model, which also reveals the physical meanings of the present model.","PeriodicalId":54802,"journal":{"name":"Journal of Hydraulic Research","volume":"61 1","pages":"322 - 332"},"PeriodicalIF":2.3,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46014273","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}
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