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Recent advances of computational aeroacoustics 被引量:2
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作者 Xiao-dong LI Min JIANG +3 位作者 Jun-hui GAO Da-kai LIN Li LIU Xiao-yan LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第1期131-140,共10页
Computational aeroacoustics (CAA) is an interdiscipline of aeroacoustics and computational fluid dynamics (CFD) for the investigation of sound generation and propagation from various aeroacoustics problems. In thi... Computational aeroacoustics (CAA) is an interdiscipline of aeroacoustics and computational fluid dynamics (CFD) for the investigation of sound generation and propagation from various aeroacoustics problems. In this review, the foundation and research scope of CAA are introduced firstly. A review of the early advances and applications of CAA is then briefly surveyed, focusing on two key issues, namely, high order finite difference scheme and non-reflecting boundary condition. Furthermore, the advances of CAA during the past five years are highlighted. Finally, the future prospective of CAA is briefly discussed. 展开更多
关键词 aeroacoustics computational aeroacoustics (CAA) high order finite difference scheme non-reflecting boundary condition
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ACOUSTIC PROPAGATION IN SHEARED MEAN FLOW USING COMPUTATIONAL AEROACOUSTICS 被引量:1
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作者 司海青 王兵 吴晓军 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2013年第1期33-38,共6页
Acoustic propagation problems in the sheared mean flow are numerically investigated using different acoustic propagation equations , including linearized Euler equations ( LEE ) and acoustic perturbation equations ( A... Acoustic propagation problems in the sheared mean flow are numerically investigated using different acoustic propagation equations , including linearized Euler equations ( LEE ) and acoustic perturbation equations ( APE ) .The resulted acoustic pressure is compared for the cases of uniform mean flow and sheared mean flow using both APE and LEE.Numerical results show that interactions between acoustics and mean flow should be properly considered to better understand noise propagation problems , and the suitable option of the different acoustic equations is indicated by the present comparisons.Moreover , the ability of APE to predict acoustic propagation is validated.APE can replace LEE when the 3-D flow-induced noise problem is solved , thus computational cost can decrease. 展开更多
关键词 computational aeroacoustics acoustic propagation problems sheared mean flow acoustic propagation equations
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Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan 被引量:1
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作者 Mohammad Jafari Atta Sojoudi Parinaz Hafezisefat 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第2期483-494,共12页
Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study... Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated. 展开更多
关键词 Bladeless fan · computational fluid dynamic (CFD) · aeroacoustic performance · Ffowcs Williams and Hawkings (FW-H) formulation
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Aircraft noise and its nearfield propagation computations 被引量:8
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作者 Xin Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第4期960-977,共18页
Noise generated by civil transport aircraft during take-off and approach-to-land phases of operation is an environmental problem. The aircraft noise problem is firstly reviewed in this article. The review is followed ... Noise generated by civil transport aircraft during take-off and approach-to-land phases of operation is an environmental problem. The aircraft noise problem is firstly reviewed in this article. The review is followed by a description and assessment of a number of sound propagation methods suitable for applications with a background mean flow field pertinent to aircraft noise. Of the three main areas of the noise problem, i.e. generation, propagation, and ra- diation, propagation provides a vital link between near-field noise generation and far-field radiation. Its accurate assessment ensures the overall validity of a prediction model. Of the various classes of propagation equations, linearised Euler equations are often casted in either time domain or frequency domain. The equations are often solved numerically by computational aeroacoustics techniques, bur are subject to the onset of Kelvin-Helmholtz (K-H) instability modes which may ruin the solutions. Other forms of linearised equations, e.g. acoustic perturbation equations have been proposed, with differing degrees of success. 展开更多
关键词 Aircraft noise computational aeroacoustics Sound propagation
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Numerical simulation on the NACA0018 airfoil self-noise generation 被引量:4
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作者 Min Jiang Xiaodong Li +1 位作者 Baohong Bai Dakai Lin 《Theoretical & Applied Mechanics Letters》 2012年第5期39-42,共4页
Airfoil self-noise is a common phenomenon for many engineering applications. Aiming to study the underlying mechanism of airfoil self-noise at low Mach number and moderate Reynolds number flow, a numerical investigati... Airfoil self-noise is a common phenomenon for many engineering applications. Aiming to study the underlying mechanism of airfoil self-noise at low Mach number and moderate Reynolds number flow, a numerical investigation is presented on noise generation by flow past NACA0018 airfoil. Based on a high-order accurate numerical method, both the near-field hydrodynamics and the far-field acoustics are computed simultaneously by performing direct numerical simulation. The mean flow properties agree well with the experimental measurements. The characteristics of aerodynamic noise are investigated at various angles of attack. The obtained results show that inclining the airfoil could enlarge turbulent intensity and produce larger scale of vortices. The sound radiation is mainly towards the upper and lower directions of the airfoil surface. At higher angle of attack, the tonal noise tends to disappear and the noise spectrum displays broad-band features. 展开更多
关键词 direct numerical simulation computational aeroacoustics airfoil self-noise broad-band features
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COMPACT FINITE VOLUME SCHEMES AND THEIR APPLICATIONS
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作者 Ju Hongbin (School of Power and Energy Engineering, Shanghai Jiaotong University, Shanghai, 200030, China) Shen Mengyu (Dept. of Engineering Mechanics, Tsinghua University, Beijing, 100084, China) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1997年第4期18-25,共8页
A class of Compact Finite Volume Schemes (CFVS) with small support stencils are developed based on a new reconstruction method for cell face variables. The accumulative errors of these schemes for a scalar wave equat... A class of Compact Finite Volume Schemes (CFVS) with small support stencils are developed based on a new reconstruction method for cell face variables. The accumulative errors of these schemes for a scalar wave equation are analyzed and compared. The established compact schemes are proved suitable for steady and unsteady flow simulations by several numerical experiments in this paper. 展开更多
关键词 computational fluid dynamics cascade flow unsteady flow computational aeroacoustics finite volume scheme
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Numerical Modelling of Aerodynamic Noise in Compressible Flows
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作者 Slawomir Dykas Sebastian Rulik Wlodzimierz Wroblewski 《Open Journal of Fluid Dynamics》 2012年第3期65-69,共5页
The solution of the AeroAcoustics (CAA) problems by means of the Direct Numerical Simulation (DNS) or even the Large Eddy Simulation (LES) for a large computational domain is very time consuming and cannot be applied ... The solution of the AeroAcoustics (CAA) problems by means of the Direct Numerical Simulation (DNS) or even the Large Eddy Simulation (LES) for a large computational domain is very time consuming and cannot be applied widely for engineering applications. In this paper the in-house CFD and CAA codes are presented. The in-house CFD code is based on the LES approach whereas the CAA code is an acoustic postprocessor solving the non-linearized Euler equations for fluctuating (acoustic) variables. These codes are used to solve the aerodynamically generated sound field by a flow over a rectangular cavity with inlet Mach number 0.53. 展开更多
关键词 computational aeroacoustics Noise Pressure Waves Cavity Noise
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Numerical Investigation of Sound Generation due to Laminar Flow Past Elliptic Cylinders
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作者 Bikash Mahato Naveen Ganta Yogesh G.Bhumkar 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE CSCD 2020年第1期27-62,共36页
Numerical investigation of sound generation due to unsteady laminar flow past elliptic cylinders has been carried out using direct numerical simulation(DNS)approach at a free-stream Mach number of 0.2.Effects of aspec... Numerical investigation of sound generation due to unsteady laminar flow past elliptic cylinders has been carried out using direct numerical simulation(DNS)approach at a free-stream Mach number of 0.2.Effects of aspect ratio(0.6≤AR≤1.0)and Reynolds number(100≤Re≤160)on the characteris-tics of radiated sound fields are analyzed.Two-dimensional compressible fluid flow equations are solved on a refined grid using high resolution dispersion relation pre-serving(DRP)schemes.Using present DNS data,equivalent noise sources as given by various acoustic analogies are evaluated.Amplitudes and frequencies associated with these noise sources are further related to characteristics of disturbance pressure fields.Disturbance pressure fields are intensified with increase in Reynolds number and aspect ratio.Thus,radiated sound power increases with increase in Reynolds number and aspect ratio.Among various cases studied here,minimum and max-imum values of radiated sound power are found at Re=120&AR=0.6 and Re=160&AR=1.0,respectively.Directivity patterns show that the generated sound fields are dominated by the lift dipole for all cases.Next,proper orthogonal decomposition(POD)technique has been implemented for decomposing distur-bance pressure fields.The POD modes associated with the lift and the drag dipoles have been identified.POD analyses also clearly display that the radiated sound fields are dominated by the lift dipole only.Further,acoustic and hydrodynamic modes obtained using Doak’s decomposition method have confirmed the patterns of radiated sound field intensities. 展开更多
关键词 computational aeroacoustics acoustic analogies aeolian tones proper orthogonal decomposition Doak’s decomposition
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Sound Propagation Properties of the Discrete-Velocity Boltzmann Equation
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作者 Erlend Magnus Viggen 《Communications in Computational Physics》 SCIE 2013年第3期671-684,共14页
As the numerical resolution is increased and the discretisation error decreases,the lattice Boltzmann method tends towards the discrete-velocity Boltzmann equation(DVBE).An expression for the propagation properties of... As the numerical resolution is increased and the discretisation error decreases,the lattice Boltzmann method tends towards the discrete-velocity Boltzmann equation(DVBE).An expression for the propagation properties of plane sound waves is found for this equation.This expression is compared to similar ones from the NavierStokes and Burnett models,and is found to be closest to the latter.The anisotropy of sound propagation with the DVBE is examined using a two-dimensional velocity set.It is found that both the anisotropy and the deviation between the models is negligible if the Knudsen number is less than 1 by at least an order of magnitude. 展开更多
关键词 Lattice Boltzmann method discrete-velocity Boltzmann equation sound propagation computational aeroacoustics
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