Validation of a high-order prefactored compact code on nonlinear flows with complex geometries

Hixon, Ray; Mankbadi, Reda R.; Scott, James R.

doi:10.2514/6.2001-1103

Cited by 19 publications

(11 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[4], where thorough grid The parallel performance of the code is shown in Figure density domain size sensitivity studies have also 1, with the noticeable dc~rease in the com~utationd been conducted. The reader is referred to this paper for efficiency observed when more then eight processors more details.…”

Section: Resultsmentioning

confidence: 99%

“…Number of processor In this work, the simulations are run for longer time important to provide com~atison for ~Wferent gust periods compared to [4] since stable, time-accurate intensity levels, with the corresponding low-intensity solutions are sought not only for imposed gust results assumed to f d within the linear response limits. 'frequencies but also for higher harmonics and At first, the results of the Il~IIlericd analysis for all gust combination tones.…”

Section: Resultsmentioning

confidence: 99%

“…More time iterations are required for lower gust frequency cases in order to march Numerical Implementation through an adequate number of longer periods. Some The computational code performing nonlinear unsteady differences in results compared to the similar analysis is written in Fortran 90 and uses the WI cases in [4] can be attributed to longer convergence library for parallelization. Numerical solutions are histories in the present -.…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Nonlinear Analysis of Airfoil High-Intensity Gust Response Using a High-Order Prefactored Compact Code

Crivellini

Golubev²,

Mankbadi³

et al. 2002

8th AIAA/CEAS Aeroacoustics Conference &Amp;amp; Exhibit

View full text Add to dashboard Cite

The .nonlinear response of symmetric and loaded airfoils to an impinging vortical gust is investigated in the parametric space of gust dimension, intensity, and frequency. The study, which was designed to investigate the validity limits for a linear analysis, is implemented by applying a nonlinear high-order prefactored compact code and comparing results with linear solutions from the GUST3D frequency-domain solver. Both the unsteady aerodynamic and acoustic gust responses are examined.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear Analysis of Airfoil High-Intensity Gust Response Using a High-Order Prefactored Compact Code

Crivellini

Golubev²,

Mankbadi³

et al. 2002

8th AIAA/CEAS Aeroacoustics Conference &Amp;amp; Exhibit

View full text Add to dashboard Cite

show abstract

“…An unsteady aerodynamic code, called GUST3D [7], has been developed to solve equation (16) for flows with periodic vortical disturbances. The code uses a frequency domain approach with second-order central differences and a pressure radiation condition in the far field [8].…”

Section: Linearized Benchmark Solutionmentioning

confidence: 99%

Benchmark Solutions for Computational Aeroacoustics (CAA) Code Validation

Scott

2004

Noise Control and Acoustics

View full text Add to dashboard Cite

NASA has conducted a series of Computational Aeroacoustics (CAA) Workshops on Benchmark Problems to develop a set of realistic CAA problems that can be used for code validation. In the Third (1999) and Fourth (2003) Workshops, the single airfoil gust response problem, with real geometry effects, was included as one of the benchmark problems. Respondents were asked to calculate the airfoil RMS pressure and far-field acoustic intensity for different airfoil geometries and a wide range of gust frequencies. This paper presents the validated solutions that have been obtained to the benchmark problem, and in addition, compares them with classical flat plate results. It is seen that airfoil geometry has a strong effect on the airfoil unsteady pressure, and a significant effect on the far-field acoustic intensity. Those parts of the benchmark problem that have not yet been adequately solved are identified and presented as a challenge to the CAA research community.

show abstract

“…The method is generally leading to excessive dissipation for the timedependent CAA problems. In contrast, the methods of artificial selective damping [110] and implicit/explicit filters [9,142] absorb spurious numerical waves in the unresolved high wavenumber, whilst kept the resolved wave components unaffected. Among these methods, an implicit filter provides better performance than an explicit filter.…”

Section: Artificial Selective Damping and Filtersmentioning

confidence: 99%

Adaptive Mesh Refinement for Computational Aeroacoustics

Huang

Zhang

2005

11th AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

This thesis describes a parallel block-structured adaptive mesh refinement (AMR) method that is employed to solve some computational aeroacoustic problems with the aim of improving the computational efficiency. AMR adaptively refines and coarsens a computational mesh along with sound propagation to increase grid resolution only in the area of interest.While sharing many of the same features, there is a marked difference between the current and the established AMR approaches. Rather than low-order schemes generally used in the previous approaches, a high-order spatial difference scheme is employed to improve numerical dispersion and dissipation qualities. To use a highorder scheme with AMR, a number of numerical issues associated with fine-coarse block interfaces on an adaptively refined mesh, such as interpolations, filter and artificial selective damping techniques and accuracy are addressed. In addition, the asymptotic stability and the transient behaviour of a high-order spatial scheme on an adaptively refined mesh are also studied with eigenvalue analysis and pseudospectra analysis respectively. In addition, the fundamental AMR algorithm is simplified in order to make the work of implementation more manageable.Particular emphasis has been placed on solving sound radiation from generic aero-engine bypass geometry with mean flow. The approach of AMR is extended to support a body-fitted multi-block mesh. The radiation from an intake duct is modelled by the linearised Euler equations, while the radiation from an exhaust duct is modelled by the extended acoustic perturbation equations to suppress hydrodynamic instabilities generated in a sheared mean flow. After solving the near-field sound solution, the associated far-field sound directivity is estimated by solving the Ffowcs Williams-Hawkings equation. The overall results demonstrate the accuracy and the efficiency of the presented AMR method, but also reveal some limitations. The possible methods to avoid these limitations are given at the end of this thesis.

show abstract

Validation of a high-order prefactored compact code on nonlinear flows with complex geometries

Cited by 19 publications

References 13 publications

Nonlinear Analysis of Airfoil High-Intensity Gust Response Using a High-Order Prefactored Compact Code

Nonlinear Analysis of Airfoil High-Intensity Gust Response Using a High-Order Prefactored Compact Code

Benchmark Solutions for Computational Aeroacoustics (CAA) Code Validation

Adaptive Mesh Refinement for Computational Aeroacoustics

Contact Info

Product

Resources

About