Journal of Fluids and Structures最新文献

{"title":"Synchronized shock wave and compliant wall interactions: Experimental characterization and aeroelastic modeling","authors":"C. Riveiro Moreno ,&nbsp;M. Couliou ,&nbsp;N. Fabbiane ,&nbsp;R. Bur ,&nbsp;O. Marquet","doi":"10.1016/j.jfluidstructs.2024.104142","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104142","url":null,"abstract":"<div><p>The static and dynamic interaction of a normal shock wave (upstream Mach number 1.35) with a compliant wall is characterized experimentally by schlieren visualizations and an optical displacement sensor. Depending on the location of the shock wave along the compliant wall, three different regimes of interaction are found: large-amplitude synchronized regime, small-amplitude synchronized regime and unsynchronized regime. The regime of large-amplitude synchronized oscillations is found for shock locations close to the mid-point of the compliant wall along the streamwise direction; at this location, the coupled system locks to the second vibration frequency of the structure. Three regimes of small-amplitude synchronized oscillations are found depending on the shock position. When the shock is located upstream the center of the compliant wall, the shock may oscillate either periodically at the frequency of the first vibration mode or quasi-periodically with highest amplitudes at the three frequencies of the vibration modes. When the shock is located downstream the center of the compliant wall, the shock oscillates periodically at the frequency of the third vibration mode. Finally, close to the trailing edge of the compliant wall, the shock oscillation is not synchronized with the compliant wall which oscillates with a very small amplitude. An empirical model is proposed to investigate the energy exchange between the flow and the compliant wall during the limit cycle oscillations. A negative aerodynamic damping – and, hence, the possibility of a limit cycle – is observed when a sufficiently extended separation is considered in the model for the pressure distribution at the wall.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S088997462400077X/pdfft?md5=99f79a674d3bc707715d170d9d544237&pid=1-s2.0-S088997462400077X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141323372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of angle of attack on the large oscillations of a thin elliptical cylinder","authors":"Jonathan C.C. Lo ,&nbsp;Mark C. Thompson ,&nbsp;Kerry Hourigan ,&nbsp;Jisheng Zhao","doi":"10.1016/j.jfluidstructs.2024.104153","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104153","url":null,"abstract":"<div><p>The effect of angle of attack on the flow-induced vibration (FIV) response of an elastically mounted thin elliptical cylinder has been investigated by measuring the structural displacement and fluid forces acting on the body in water-channel experiments. Specifically, an elliptical cylinder with a cross-sectional elliptical ratio of <span><math><mrow><mi>ɛ</mi><mo>=</mo><mi>b</mi><mo>/</mo><mi>a</mi><mo>=</mo><mn>5</mn></mrow></math></span> was chosen due to the presence of a region of vibration response associated with the combined effect of vortex-induced vibration (VIV) and galloping, where large vibration amplitudes nearly eight times the cross-flow dimensions can be sustained. Here, <span><math><mi>a</mi></math></span> and <span><math><mi>b</mi></math></span> are the semi-minor axis (aligned with the streamwise direction) and the semi-major axis, respectively. The present experimental results demonstrated that the large vibration amplitudes (i.e. where the maximum observed value was approximately 6<span><math><mi>b</mi></math></span>) generally decrease with the angle of attack, resulting in substantial reductions for <span><math><mrow><mi>α</mi><mo>≳</mo><msup><mrow><mn>2</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> (with <span><math><mrow><mi>α</mi><mo>=</mo><mn>3</mn><mo>.</mo><mn>5</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> corresponding to a <span><math><mo>∼</mo></math></span> 60% decrease in the maximum vibration amplitude). Particle image velocimetry (PIV) measurements revealed that the dominant vortex shedding mode consists of two single opposite-signed vortices shed per body vibration cycle. The presence of additional vorticity regions that were absent in the zero angle of attack case was also observed, including crescent-shaped wake structures and secondary inline vortices. This study shows the importance of maintaining axial symmetry in such an FIV system, and that the flow incidence angle is an essential consideration for efficient energy harvesting using this elliptical geometry.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0889974624000884/pdfft?md5=a94bb0b33ff80a21346e1f1def32874d&pid=1-s2.0-S0889974624000884-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141323373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of magnetic field on supersonic flutter characteristics of dielectric plate: Dependence amplitude-speed","authors":"Marine A. Mikilyan,&nbsp;Iren A. Vardanyan","doi":"10.1016/j.jfluidstructs.2024.104140","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104140","url":null,"abstract":"<div><p>For aircraft design, design of the wing shape (for example, as a panel) is critical as it affects aerodynamic performance. In case, when panel is made of a material with magnetic properties, magnetic field of different origin plays an important role. As aircraft designers strive for improved efficiency and performance, accurate prediction of magneto-aeroelastic effects is becoming a necessity. For example, while high aspect ratio wings have higher aerodynamic efficiency, the structural deformation of the wing under the influence of both aerodynamic load and magnetic field is no longer negligible and a coupled analysis needs to be carried out to during the design phase.</p><p>This paper offers the authors’ views on critical magneto-aeroelastic behavior for dielectric rectangular isotropic plates and is a continuation of the work (<span>Baghdasaryan et al., 2023</span>): “Supersonic flutter characteristics of dielectric rectangular plate: The effects of magneto-aero-hydrodynamic interactions, Journal of Fluids and Structures, 2023”.</p><p>The work \"Supersonic flutter characteristics of dielectric rectangular plate: The effects of magneto-aero-hydrodynamic interactions\" presents both, linear and non-linear flutter behaviour of an isotropic dielectrical plate streamlined by a perfectly conductive supersonic gas flow and immersed in a longitudinal magnetic field. It is assumed, that flowing liquid is an inviscid, non-heat-conducting one with infinite conductivity. For the first time, an analytical expression of the aerodynamic pressure accounting for an applied magnetic field is presented. This expression generalizes the formula of piston theory to account for magnetic field interactions. Based on the linear problem of aero-magneto-flutter, stability conditions are obtained and corresponding stability boundary is found. As a result, of the analytical description, the influence of magnetic field on the critical speed is investigated for different geometrical parameters and different parameters of the magnetic field. The influence of the number of modes on the critical flutter speed is investigated as well. It is shown, that the magnetic field decreases the stability boundary of a steady flutter type oscillations of rectangular plate.</p><p>Using the expressions for forces, acting on the body, and the theory of thin flexible plates the system of equations, describing vibrations and stability of plates, is obtained. Having solved the formulated boundary-value problems both qualitative and quantitative influence of magnetic field and flowing stream on the existence of non-linear flutter type oscillations and on the dependence of the amplitude of oscillations on the frequency for the fixed values of flowing stream are investigated. The presented work differs from the previous one in the subject of research. There are many studies in the scientific literature that study the amplitude-frequency dependence of both natural and forced oscillations. Ther","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141323371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of machine learning to optimize actuator configuration on an airfoil","authors":"M. Tadjfar ,&nbsp;Dj. Kamari ,&nbsp;A. Tarokh","doi":"10.1016/j.jfluidstructs.2024.104141","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104141","url":null,"abstract":"<div><p>Machine learning was used to optimize the geometric arrangement of a pair of unsteady actuators on flow separation over an efficient low Reynolds number airfoil in post-tall conditions. Large eddy simulation was used to validate the results. Two actuators: one with blowing and the other with suction openings were installed on the top surface of an airfoil at low Reynolds number of 60,000. An SD7003 airfoil at a post stall angle of attack of 13° was utilized. The boundary layer flow of the top surface was manipulated by the actuators to control flow separation. The influence of several actuator parameters: frequency, energy input, opening area, location and orientation angle were considered in an optimization of the dual actuator configuration. A genetic algorithm-based optimization was implemented to find the most effective configuration of this coupling. Since the optimization process is time-consuming, machine learning was used to train artificial neural networks to be coupled with genetic algorithm to reduce the computational cost. The artificial neural networks and their training was constantly upgraded during the optimization cycle. Results for the optimal case indicated an increase in lift coefficient and the objective function in comparison to uncontrolled case by factors of 1.88 and 3.33 respectively. We also found a reduction in drag coefficient. It was also found that using a pair of actuators was more efficient than using a single actuator.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141297977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tip shape effects on the axial-flow-induced vibration of a cantilever rod","authors":"Hao Li ,&nbsp;Andrea Cioncolini ,&nbsp;Shanying Zhang ,&nbsp;Hector Iacovides ,&nbsp;Mostafa R.A. Nabawy","doi":"10.1016/j.jfluidstructs.2024.104132","DOIUrl":"10.1016/j.jfluidstructs.2024.104132","url":null,"abstract":"<div><p>The influence of tip shape on flow-induced vibration of a cantilever rod subjected to axial water flow is experimentally investigated, through optical tracking of the rod movement and mapping of the instantaneous flow field around the rod tip. The experimental setup consists of a vertical cantilever rod housed within a tube. The rod tip shapes considered in this study include a blunt tip and cones with height-to-diameter ratios of 0.5, 1, and 2. The experiments were conducted across a Reynolds number range between 20k to 100k in both clamped-free and free-clamped configurations, representing opposite flow directions. The rod tip motion was captured using fast video image tracking, whereas the flow field near the rod tip was obtained using particle image velocimetry (PIV). The rod vibration dynamics exhibited a primarily fuzzy period-1 behavior, characterized by a periodic motion with a chaotic component. Flutter-like oscillation and buckling were also observed at higher Reynolds numbers, depending on the flow direction. The mechanisms of fluid-structure interaction involved turbulent buffeting and movement-induced excitations. Unsteady flow separation around the rod tip was identified as a further contributing mechanism to flow excitation. In the clamped-free configuration, unsteady flow separation was more pronounced for the cone tips due to the increased rod surface area in the wake region, leading to larger vibration amplitude. In the free-clamped configuration, flow separation effects were more prominent for the blunt tip, as the streamlined cone shapes were less prone to flow separations. Overall, the rod with a blunt tip resulted in smaller displacement in the clamped-free configuration, while the rods with cone tips led to smaller displacement in the free-clamped configuration.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0889974624000677/pdfft?md5=858e530e0235b2163e2ec0d38521d860&pid=1-s2.0-S0889974624000677-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141190020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aerodynamics of flapping wings with passive and active deformation","authors":"Florian Bouard ,&nbsp;Thierry Jardin ,&nbsp;Laurent David","doi":"10.1016/j.jfluidstructs.2024.104139","DOIUrl":"10.1016/j.jfluidstructs.2024.104139","url":null,"abstract":"<div><p>This paper reports direct numerical simulations of the flow past rigid and flexible flapping wings under hovering flight conditions. Both passive and active deformations are considered. It is shown that passive deformation can help increase aerodynamic performance through significant wing bending. Bending occurs at the frequency of the prescribed flapping motion and is, in this case, characterized by moderate amplitude and phase lag with respect to the prescribed flapping motion. Bending is then actively prescribed (rather than being a result of passive deformation) with varying phase lag. This allows to decouple the role of bending amplitude and phase lag on aerodynamic performance of the flapping wing. It is shown that both lift and efficiency can be significantly enhanced for phase lags around <span><math><mrow><mn>3</mn><mi>π</mi><mo>/</mo><mn>2</mn></mrow></math></span> but this enhancement reduces with increasing pitch angle. The influence of morphing on aerodynamic performance can be explained by the concomitant role of quasi-steady and unsteady effects. These results hence demonstrate that morphing can be beneficial to the aerodynamics of flapping wings. Furthermore, they can help define structural properties that promote aerodynamic performance of flapping wings through passive deformations (with relevant amplitude and phase).</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141189876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Controlling the chaotic wake of a flapping foil by tuning its chordwise flexibility","authors":"Chhote Lal Shah ,&nbsp;Dipanjan Majumdar ,&nbsp;Chandan Bose ,&nbsp;Sunetra Sarkar","doi":"10.1016/j.jfluidstructs.2024.104134","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104134","url":null,"abstract":"<div><p>Effects of chord-wise flexibility as an instrument to control chaotic transitions in the wake of a flexible flapping foil have been studied here using an immersed boundary method-based in-house fluid–structure-interaction solver. The ability of the flapping foil at an optimum level of flexibility to inhibit chaotic transition, otherwise encountered in a similar but rigid configuration, has been highlighted. The rigid foil manifests chaotic transition through a quasi-periodic-intermittency route at high dynamic plunge velocities; whereas, increasing the level of flexibility gradually regularises the aperiodic behaviour through a variety of interesting wake patterns. If flexibility is increased beyond an optimum level, aperiodicity sets in again and robust chaos is restored at very high flexibility levels. The mechanisms of triggering the order-to-chaos transition are different between the rigid and the high flexibility cases. Along the route to order and back to chaos, the flexible foil exhibits different flow-field behaviours, including far-wake switching, primary &amp; secondary vortex streets, bifurcated wakes and interactive vortices between the bifurcated wakes. The underlying interaction mechanisms of the flow-field vortices responsible for the associated dynamical signatures of the wake have been closely tracked. This study further examines the optimum propulsive performance range of the flexible flapper and investigates its connection with the periodicity/regularity of the system.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroelasticity effects induced by a single cavitation bubble collapse","authors":"Hemant J. Sagar ,&nbsp;Ould el Moctar","doi":"10.1016/j.jfluidstructs.2024.104131","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104131","url":null,"abstract":"<div><p>To investigate hydroelasticity effects on a single cavitation bubble dynamic, a focused laser was used to generate the bubble in water near a flexible aluminium foil fixed to a specimen holder with a circular aperture to allow the foil to vibrate. The bubble was generated below the foil's center. A laser-based optical sensor measured the displacement at the center of the foil. Simultaneously, a high-speed camera monitored the bubble's dynamics to correlate it with the foil's displacement. By directly measuring the foil's displacements, we provided building block missing in previous investigations. We found that a key difference between bubble dynamics near a rigid and an elastic structure was that, at relative wall distances larger or equal to unity, the bubble did not collapse on the elastic foil. The bubble's dynamics caused dominant foil displacements during its first growth (after plasma seeding) and during its subsequent collapse. Foil displacements during the bubble's first collapse were about twice as large as those during its growth phase. For lower relative wall distances, the induced foil displacements were significant until the bubble's third collapse. At larger relative wall distances, the bubble did not collapse on the elastic foil and, thus, it did not induce erosion. However, it caused foil vibrations and, therefore, may contribute to the foil's structural fatigue damage. Our study postulates that the cavitation may not be erosive, however it can induce impulsive loads causing vibrations and thereby fatigue damage of nearby structures.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0889974624000665/pdfft?md5=7f7074d4d5e4303315121fded4000b3a&pid=1-s2.0-S0889974624000665-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141163654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bandgap accuracy and characteristics of fluid-filled periodic pipelines utilizing precise parameters transfer matrix method","authors":"Wenjie Li,&nbsp;Xiangxi Kong,&nbsp;Qi Xu,&nbsp;Ziyu Hao","doi":"10.1016/j.jfluidstructs.2024.104136","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104136","url":null,"abstract":"<div><p>The phononic crystal theory provides a novel approach for effectively controlling the bending vibrations in fluid-filled pipelines. This paper innovatively proposes the precise parameters transfer matrix method to investigate the band calculation accuracy and bandgap characteristics of fluid-filled periodic pipelines with various beam types. Firstly, the differential equations for bending vibration of fluid-filled pipelines are established based on deformation and force analysis. The parameters of the system state are precisely represented by the structural form of multiplying the constitutive matrix with the derivative matrix. Combined with Bloch's theorem, the novel precise parameters transfer matrix method for calculating the band structure is proposed. Secondly, the validity of this method is verified through a comparison with finite element simulation results. A detailed analysis is provided regarding the mechanism of bandgap formation and the effect of fluid filling on the band structure. Then, the influence of shear deformation, moment of inertia, and their coupling on the band calculation accuracy for fluid-filled periodic pipelines is studied based on various beam theories. Finally, it delves into the bandgap characteristics of fluid-filled periodic pipelines under different material parameters, structural parameters, and excitation conditions. This research offers valuable insights for the structural design and vibration damping application in fluid-filled periodic pipelines, providing theoretical support for accurately determining their bandgaps.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aeroacoustic effect of boundary layer separation control by rod vortex generators on the DU96-W-180 airfoil","authors":"Thanushree Suresh ,&nbsp;Pawel Flaszynski ,&nbsp;Alejandro Rubio Carpio ,&nbsp;Marcin Kurowski ,&nbsp;Michal Piotrowicz ,&nbsp;Oskar Szulc","doi":"10.1016/j.jfluidstructs.2024.104133","DOIUrl":"https://doi.org/10.1016/j.jfluidstructs.2024.104133","url":null,"abstract":"<div><p>An experimental campaign to study the impact of a distinct type of vortex generator — rod type (RVG), on the flow characteristics and the acoustic far-field pressure of a wind turbine airfoil, is conducted. Airfoils exhibit decreased aerodynamic performance at high inflow angles due to turbulent boundary layer flow separation. RVGs are applied to mitigate the flow separation. However, this benefit is accompanied by an acoustic penalty. An assessment of the impact of RVGs on the far-field noise emission is conducted for the DU96-W-180 airfoil. The evolution of the boundary layer impacted by the rods is analyzed through Particle Image Velocimetry (PIV) measurements. The resulting reduction in the separation zone is observed through oil flow visualization. Analysis of the sound spectrum for airfoils with/without RVGs is conducted for a range of frequencies (300 Hz to 4000 Hz). Results show a reduction of the noise level at relatively low frequencies, at the expense of an increased noise level in the mid-high frequency ranges. While the former is caused by the reduction of the flow separation, the latter is determined by the combined contribution of the noise scattered by the RVG and by the change in boundary layer characteristics at the airfoil trailing edge.</p></div>","PeriodicalId":54834,"journal":{"name":"Journal of Fluids and Structures","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141090655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}