Pub Date : 2023-07-03DOI: 10.1088/1873-7005/ace37b
Lizhong Huang, Chun Shao, Ruijin Wang, Jiayou Du, Zefei Zhu
The sedimentation of particles with various shapes and orientations in a closed channel using smoothed particle hydrodynamics is investigated in this paper. The continuity and momentum equations of both fluid and solid are discretized using kernel approximation in the Lagrangian frame. The sedimentation behavior of different general shapes, including circle, pentagon, square, ellipse, rectangle, and triangle, at various initial orientations in the suspending fluid is simulated. The stable equilibrium orientation (SEO) of these shapes is examined, excluding the circle which serves as a validation case. Specifically, the major axis of the ellipse and rectangle tends to align horizontally, whereas the orientations of the pentagon and square seem to be random due to the lack of a major axis and the finite channel height. The settling behavior of the three types of triangles is also discussed, and the von Mises stress of these shapes during their settling is presented. This study offers valuable insights into fluid-particle interactions, specifically regarding the SEO and internal stress of settling particles with varying shapes and orientations.
{"title":"Sedimentation of particles with various shapes and orientations in a closed channel using smoothed particle hydrodynamics","authors":"Lizhong Huang, Chun Shao, Ruijin Wang, Jiayou Du, Zefei Zhu","doi":"10.1088/1873-7005/ace37b","DOIUrl":"https://doi.org/10.1088/1873-7005/ace37b","url":null,"abstract":"The sedimentation of particles with various shapes and orientations in a closed channel using smoothed particle hydrodynamics is investigated in this paper. The continuity and momentum equations of both fluid and solid are discretized using kernel approximation in the Lagrangian frame. The sedimentation behavior of different general shapes, including circle, pentagon, square, ellipse, rectangle, and triangle, at various initial orientations in the suspending fluid is simulated. The stable equilibrium orientation (SEO) of these shapes is examined, excluding the circle which serves as a validation case. Specifically, the major axis of the ellipse and rectangle tends to align horizontally, whereas the orientations of the pentagon and square seem to be random due to the lack of a major axis and the finite channel height. The settling behavior of the three types of triangles is also discussed, and the von Mises stress of these shapes during their settling is presented. This study offers valuable insights into fluid-particle interactions, specifically regarding the SEO and internal stress of settling particles with varying shapes and orientations.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43273477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-03DOI: 10.1088/1873-7005/ace37c
S. Rajakumar, D. A. Perumal, A. Yadav
We utilize the lattice Boltzmann method to conduct three-dimensional simulations of incompressible flows in oscillating cubic lid-driven cavities. Our investigation focuses on examining the impact of Reynolds number and oscillating frequency on the flow field. Notably, we observe that the flow field can be adequately approximated as two-dimensional within the low and intermediate Reynolds number range, but this approximation is no longer valid for high Reynolds numbers. Additionally, we find that high Reynolds numbers correspond to transient flow fields, while low and moderate Reynolds numbers exhibit quasi-steady periodic flow fields. Our study holds significant relevance for industrial processing applications, where the Reynolds numbers and oscillating frequencies can be optimized to achieve a desired flow field.
{"title":"Three-dimensional simulations of fluid flows in oscillating lid-driven cavities using lattice Boltzmann method","authors":"S. Rajakumar, D. A. Perumal, A. Yadav","doi":"10.1088/1873-7005/ace37c","DOIUrl":"https://doi.org/10.1088/1873-7005/ace37c","url":null,"abstract":"We utilize the lattice Boltzmann method to conduct three-dimensional simulations of incompressible flows in oscillating cubic lid-driven cavities. Our investigation focuses on examining the impact of Reynolds number and oscillating frequency on the flow field. Notably, we observe that the flow field can be adequately approximated as two-dimensional within the low and intermediate Reynolds number range, but this approximation is no longer valid for high Reynolds numbers. Additionally, we find that high Reynolds numbers correspond to transient flow fields, while low and moderate Reynolds numbers exhibit quasi-steady periodic flow fields. Our study holds significant relevance for industrial processing applications, where the Reynolds numbers and oscillating frequencies can be optimized to achieve a desired flow field.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48971635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-07-03DOI: 10.1088/1873-7005/ace37a
Y. Vinod, I. Shivakumara, K. R. Raghunatha
The initiation of thermosolutal convective instability is investigated in a horizontal porous layer saturated by a shear-thinning fluid following Ellis’ rheology. The porous layer is heated as well as salted from below and a basic horizontal throughflow prompted by the prescribed pressure gradient is considered. The linear stability analysis is performed using normal mode analysis and the threshold conditions for the onset of convection are obtained in a closed form. The imposed horizontal pressure gradient and the solute concentration gradient reinforce together in resulting the onset of convection through oscillatory motions. The transverse rolls are the most unstable which are found to be both travelling and non-travelling in the reference frame comoving with the basic throughflow. The effect of increasing the Ellis power-law index and the solute Darcy-Rayleigh number is to stabilise, while an increase in the Darcy-Ellis number is to destabilise the base flow. The pressure and temperature/solute concentration lines are presented at the critical state. The results delineated under the limiting cases are shown to be in agreement with those published previously.
{"title":"Exploration of rheological behavior of an Ellis fluid on the onset of thermosolutal porous convection","authors":"Y. Vinod, I. Shivakumara, K. R. Raghunatha","doi":"10.1088/1873-7005/ace37a","DOIUrl":"https://doi.org/10.1088/1873-7005/ace37a","url":null,"abstract":"The initiation of thermosolutal convective instability is investigated in a horizontal porous layer saturated by a shear-thinning fluid following Ellis’ rheology. The porous layer is heated as well as salted from below and a basic horizontal throughflow prompted by the prescribed pressure gradient is considered. The linear stability analysis is performed using normal mode analysis and the threshold conditions for the onset of convection are obtained in a closed form. The imposed horizontal pressure gradient and the solute concentration gradient reinforce together in resulting the onset of convection through oscillatory motions. The transverse rolls are the most unstable which are found to be both travelling and non-travelling in the reference frame comoving with the basic throughflow. The effect of increasing the Ellis power-law index and the solute Darcy-Rayleigh number is to stabilise, while an increase in the Darcy-Ellis number is to destabilise the base flow. The pressure and temperature/solute concentration lines are presented at the critical state. The results delineated under the limiting cases are shown to be in agreement with those published previously.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44970926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-06-01DOI: 10.1088/1873-7005/acdf7c
Akira Noguchi, Yuki Tange, T. Itano, M. Sugihara-Seki
In blood flow through microvessels, platelets are known to be distributed in high concentrations near the vessel wall, termed ‘margination’ or ‘near-wall excess’. At the confluence of two vessels, this preferential distribution of platelets is thought to be compromised and reconstituted in the downstream main vessel. The present study aimed to investigate the distance of this margination reconstruction from the confluence by in vitro experiments using platelet-sized fluorescent particles as a platelet surrogate and a Y-shaped confluence microchannel with rectangular cross sections. Fluorescence microscopy was performed using a confocal laser scanning microscope system to measure the distribution of particles in the red blood cell suspension flow. Immediately after confluence, particles were highly concentrated along a narrow band in the middle of the channel width, where particles located near the inner wall of the daughter channels flowed in. This dense band of particles faded downstream and disappeared less than 5 mm from the confluence. This margination distance is comparable to or smaller than the margination development distance in straight channels, but much smaller than that after bifurcation.
{"title":"Margination of platelet-sized particles in red blood cell suspensions flowing through a Y-shaped confluence microchannel","authors":"Akira Noguchi, Yuki Tange, T. Itano, M. Sugihara-Seki","doi":"10.1088/1873-7005/acdf7c","DOIUrl":"https://doi.org/10.1088/1873-7005/acdf7c","url":null,"abstract":"In blood flow through microvessels, platelets are known to be distributed in high concentrations near the vessel wall, termed ‘margination’ or ‘near-wall excess’. At the confluence of two vessels, this preferential distribution of platelets is thought to be compromised and reconstituted in the downstream main vessel. The present study aimed to investigate the distance of this margination reconstruction from the confluence by in vitro experiments using platelet-sized fluorescent particles as a platelet surrogate and a Y-shaped confluence microchannel with rectangular cross sections. Fluorescence microscopy was performed using a confocal laser scanning microscope system to measure the distribution of particles in the red blood cell suspension flow. Immediately after confluence, particles were highly concentrated along a narrow band in the middle of the channel width, where particles located near the inner wall of the daughter channels flowed in. This dense band of particles faded downstream and disappeared less than 5 mm from the confluence. This margination distance is comparable to or smaller than the margination development distance in straight channels, but much smaller than that after bifurcation.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46968591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-06-01DOI: 10.1088/1873-7005/acdc4e
Dapeng Deng, Huifang Dong, Yusheng Liang
In this paper, a lattice Boltzmann method is used to simulate the dynamic behavior of a droplet flows through a constricted channel, where an obstacle is placed in the center of the constricted channel to split the droplet. The method is first used to simulate the effect of the capillary number Ca on the volume of the divided daughter droplets. Results show that the volume difference between the daughter droplets above and below the obstacle increases as Ca increases. We also find that reducing the capillary number is conducive to the droplet splitting into two daughter droplets with similar volume. The method is then used to simulate the influence of the viscosity ratio λ on the droplet flows through a constricted channel. As λ increases, the volume difference between the daughter droplets above and below the obstacle decreases. Finally, the influence of the confinement ratio Wc on the evolution of the droplet morphology is investigated. With increase in Wc , the volume difference between the daughter droplets above and below the obstacle increases. When Wc⩾1 , the droplet does not break up and completely enters the bottom channel. Comparing with the converging-diverging and ratchet channels, the constricted splitting channel is more conductive to the breakup of the droplet neck.
{"title":"The dynamic behavior of a droplet flows through a constricted splitting channel: a lattice Boltzmann study","authors":"Dapeng Deng, Huifang Dong, Yusheng Liang","doi":"10.1088/1873-7005/acdc4e","DOIUrl":"https://doi.org/10.1088/1873-7005/acdc4e","url":null,"abstract":"In this paper, a lattice Boltzmann method is used to simulate the dynamic behavior of a droplet flows through a constricted channel, where an obstacle is placed in the center of the constricted channel to split the droplet. The method is first used to simulate the effect of the capillary number Ca on the volume of the divided daughter droplets. Results show that the volume difference between the daughter droplets above and below the obstacle increases as Ca increases. We also find that reducing the capillary number is conducive to the droplet splitting into two daughter droplets with similar volume. The method is then used to simulate the influence of the viscosity ratio λ on the droplet flows through a constricted channel. As λ increases, the volume difference between the daughter droplets above and below the obstacle decreases. Finally, the influence of the confinement ratio Wc on the evolution of the droplet morphology is investigated. With increase in Wc , the volume difference between the daughter droplets above and below the obstacle increases. When Wc⩾1 , the droplet does not break up and completely enters the bottom channel. Comparing with the converging-diverging and ratchet channels, the constricted splitting channel is more conductive to the breakup of the droplet neck.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43478093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work proposes an innovative approach for supersonic flow field modeling around airfoils based on sparse convolutional neural networks (SCNNs) and Bézier generative adversarial network (GAN), where (1) the SCNN model is built to end-to-end predict supersonic compressible physical flow fields around airfoils from spatially-sparse geometries and (2) the trained Bézier-GAN is utilized to generate plenty of smooth airfoils as well as the latent codes representing airfoils. The spatially-sparse positions of airfoil geometry are represented using signed distance function (SDF). Particularly, the latent codes are merged with the SDF matrix and the Mach number to form the input of the SCNN model, effectively making the SCNN model possess more robust geometric adaptability to different flow conditions. The most significant contribution compared to the regular convolutional neural network is that SCNN introduces sparse convolutional operations to process spatially-sparse input matrix, specifically, which only focuses on the local area with flow information when performing convolution, eventually saving memory usage and improving the network’s attention on the flow area. Further, the testing results show that the SCNN model can more accurately predict supersonic flow fields with a mean absolute error lower than 5% and save 40% of graphics processing unit memory. These results indicate that the proposed SCNN model can capture the shock wave features of supersonic flow fields and improve learning efficiency and computing efficiency.
{"title":"Computationally effective estimation of supersonic flow field around airfoils using sparse convolutional neural network","authors":"Ming-yu Wu, Jiang-Zhou Peng, Zhi-ming Qiu, Zhi-Hua Chen, Yu-Bai Li, Wei-Tao Wu","doi":"10.1088/1873-7005/acd7a0","DOIUrl":"https://doi.org/10.1088/1873-7005/acd7a0","url":null,"abstract":"This work proposes an innovative approach for supersonic flow field modeling around airfoils based on sparse convolutional neural networks (SCNNs) and Bézier generative adversarial network (GAN), where (1) the SCNN model is built to end-to-end predict supersonic compressible physical flow fields around airfoils from spatially-sparse geometries and (2) the trained Bézier-GAN is utilized to generate plenty of smooth airfoils as well as the latent codes representing airfoils. The spatially-sparse positions of airfoil geometry are represented using signed distance function (SDF). Particularly, the latent codes are merged with the SDF matrix and the Mach number to form the input of the SCNN model, effectively making the SCNN model possess more robust geometric adaptability to different flow conditions. The most significant contribution compared to the regular convolutional neural network is that SCNN introduces sparse convolutional operations to process spatially-sparse input matrix, specifically, which only focuses on the local area with flow information when performing convolution, eventually saving memory usage and improving the network’s attention on the flow area. Further, the testing results show that the SCNN model can more accurately predict supersonic flow fields with a mean absolute error lower than 5% and save 40% of graphics processing unit memory. These results indicate that the proposed SCNN model can capture the shock wave features of supersonic flow fields and improve learning efficiency and computing efficiency.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44949674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-05-16DOI: 10.1088/1873-7005/acd5fb
R. Kian, M. Mahdieh
The propagation of dust acoustic solitary waves (DASWs) has been investigated in a magnetized dusty plasma consisting of negatively charged dust particles, nonthermal ions and nonthermal electrons. Using reductive perturbation method, the Korteweg-de-Vries (K-dV) equation is derived. It is found that the basic structures (such as polarity, amplitude, width) of DASWs are influenced by nonthermal ions and nonthermal electrons. The results show that both compressive and rarefactive DASWs exist in such dusty plasma. It is observed that by increasing the nonthermality parameter of ions and electrons, the nonlinear wave phase velocity increases. Furthermore, nonthermal distributed ions have more effect on the nonlinear wave phase velocity of the DASWs than nonthermal distributed electrons. The dependence of the angle that the external magnetic field makes with the propagation direction of wave on the amplitude and width of DASWs has been also investigated. It was concluded that this angle strongly affects the DASWs. Finally, the effect of the magnetic field appears only in the width and not in the amplitude of the DASWs. The findings of this study can be helpful in understanding the structures of DASWs in the dusty plasma in which both nonthermal ions and nonthermal electrons exist. Such structures can be found in different regions of space and astrophysics mediums such as the upper ionosphere and Saturn’s E-ring.
{"title":"Small amplitude dust acoustic solitary waves in a magnetized dusty plasma with nonthermal distribution for both electrons and ions","authors":"R. Kian, M. Mahdieh","doi":"10.1088/1873-7005/acd5fb","DOIUrl":"https://doi.org/10.1088/1873-7005/acd5fb","url":null,"abstract":"The propagation of dust acoustic solitary waves (DASWs) has been investigated in a magnetized dusty plasma consisting of negatively charged dust particles, nonthermal ions and nonthermal electrons. Using reductive perturbation method, the Korteweg-de-Vries (K-dV) equation is derived. It is found that the basic structures (such as polarity, amplitude, width) of DASWs are influenced by nonthermal ions and nonthermal electrons. The results show that both compressive and rarefactive DASWs exist in such dusty plasma. It is observed that by increasing the nonthermality parameter of ions and electrons, the nonlinear wave phase velocity increases. Furthermore, nonthermal distributed ions have more effect on the nonlinear wave phase velocity of the DASWs than nonthermal distributed electrons. The dependence of the angle that the external magnetic field makes with the propagation direction of wave on the amplitude and width of DASWs has been also investigated. It was concluded that this angle strongly affects the DASWs. Finally, the effect of the magnetic field appears only in the width and not in the amplitude of the DASWs. The findings of this study can be helpful in understanding the structures of DASWs in the dusty plasma in which both nonthermal ions and nonthermal electrons exist. Such structures can be found in different regions of space and astrophysics mediums such as the upper ionosphere and Saturn’s E-ring.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48112347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-04-27DOI: 10.1088/1873-7005/acd0d4
L. L. Ferrás, A. Afonso
This work presents a comparison between the PTT-X (extended Phan-Thien and Tanner (PTT)) and the generalised PTT (gPTT) viscoelastic models. The PTT-X model was derived based on a combination of reptation and network theories, allowing in this way a microstructural justification for the kernel function. The gPTT model is based on the network theory, with an empirical kernel function for the rate of destruction of junctions, that proved to be effective fitting experimental rheological data for polymer melts and solutions. A review on the background of both models is provided and the two models are then compared considering simple flows. This comparison allows one to attribute in some way a microstructural nature to the parameters involved in the gPTT model. Also, a new analytical solution is derived for the Poiseuille flow of the PTT-X model.
{"title":"New insights into the extended and generalised PTT constitutive differential equations: weak flows","authors":"L. L. Ferrás, A. Afonso","doi":"10.1088/1873-7005/acd0d4","DOIUrl":"https://doi.org/10.1088/1873-7005/acd0d4","url":null,"abstract":"This work presents a comparison between the PTT-X (extended Phan-Thien and Tanner (PTT)) and the generalised PTT (gPTT) viscoelastic models. The PTT-X model was derived based on a combination of reptation and network theories, allowing in this way a microstructural justification for the kernel function. The gPTT model is based on the network theory, with an empirical kernel function for the rate of destruction of junctions, that proved to be effective fitting experimental rheological data for polymer melts and solutions. A review on the background of both models is provided and the two models are then compared considering simple flows. This comparison allows one to attribute in some way a microstructural nature to the parameters involved in the gPTT model. Also, a new analytical solution is derived for the Poiseuille flow of the PTT-X model.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44398728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-04-25DOI: 10.1088/1873-7005/acd025
L. M. Lin
Through direct numerical simulations, the transition from pure mode A to mode B in the near wake of a circular cylinder is studied with no effect of vortex dislocations. The Reynolds number is computed from 100 to 330 with the computational spanwise length of 4 diameters. In the present part, fluid forces are analyzed. The results show that mode swapping still exists in the range of Reynolds numbers from 230 to 240. In this range, fluid forces with low and high levels occur intermittently. Moreover, when the critical Reynolds number of 193 ( ± 0.5) is exceeded, with the increase of the Reynolds number, the vortex-shedding frequency gradually shifts from a single low frequency, high and low frequency coexistence to a single high frequency.
{"title":"Phase transition between pure modes A and B in a circular cylinder’s wake. Part I: analysis of fluid forces","authors":"L. M. Lin","doi":"10.1088/1873-7005/acd025","DOIUrl":"https://doi.org/10.1088/1873-7005/acd025","url":null,"abstract":"Through direct numerical simulations, the transition from pure mode A to mode B in the near wake of a circular cylinder is studied with no effect of vortex dislocations. The Reynolds number is computed from 100 to 330 with the computational spanwise length of 4 diameters. In the present part, fluid forces are analyzed. The results show that mode swapping still exists in the range of Reynolds numbers from 230 to 240. In this range, fluid forces with low and high levels occur intermittently. Moreover, when the critical Reynolds number of 193 ( ± 0.5) is exceeded, with the increase of the Reynolds number, the vortex-shedding frequency gradually shifts from a single low frequency, high and low frequency coexistence to a single high frequency.","PeriodicalId":56311,"journal":{"name":"Fluid Dynamics Research","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46789409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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