### Abstract

As transport aircraft engines get larger and larger, the dominant noise source component becomes the fan (forward and aft). A computational massively parallel aeroacoustics algorithm that has been developed to predict forward noise radiation from such engines is described in this paper. The numerical algorithm is a 4th order accurate (both in space and time), Euler/Navier-Stokes solver that is written in essentially High Performance Fortran (HPF). The scheme uses the classical four-stage Runge-Kutta time integration, central differencing for spatial derivatives, and a blend of second and sixth order, Jameson type artificial dissipation to sup press high frequency numerical oscillations. On the outer boundaries of the computational domain, non-reflecting boundary conditions are used. Specifically the algorithm has been optimized for the CM-5 of Thinking Machines Corporation. An overlap ping mixture of the fluxes of the interior points and the far-field boundary points is established by making use of the MERGE statement which the programming languages, CM Fortran and Fortran 90, facilitate. This procedure leads to a simultaneous discretization of the spatial derivatives for the three different sets of governing equations across the domain: Navier-Stokes/Euler equations, radiation boundary conditions and outflow boundary conditions. Hence, approximately 60% reduction in computing the residuals of the governing equations is obtained on the Connection Machine computers. Results for a steady engine inlet flow, oscillating flat plate in a viscous fluid, scattering from a sphere, sound radiation from a baffled oscillating piston, and sound propagation through an axisymmetric inlet are presented.

Original language | English (US) |
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Pages | 527-539 |

Number of pages | 13 |

State | Published - Jan 1 1995 |

Event | 12th Computational Fluid Dynamics Conference, 1995 - San Diego, United States Duration: Jun 19 1995 → Jun 22 1995 |

### Other

Other | 12th Computational Fluid Dynamics Conference, 1995 |
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Country | United States |

City | San Diego |

Period | 6/19/95 → 6/22/95 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Engineering(all)

### Cite this

*A new efficient algorithm for computational aeroacoustics on massively parallel computers*. 527-539. Paper presented at 12th Computational Fluid Dynamics Conference, 1995, San Diego, United States.

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**A new efficient algorithm for computational aeroacoustics on massively parallel computers.** / Özyörük, Yusuf; Long, Lyle Norman.

Research output: Contribution to conference › Paper

TY - CONF

T1 - A new efficient algorithm for computational aeroacoustics on massively parallel computers

AU - Özyörük, Yusuf

AU - Long, Lyle Norman

PY - 1995/1/1

Y1 - 1995/1/1

N2 - As transport aircraft engines get larger and larger, the dominant noise source component becomes the fan (forward and aft). A computational massively parallel aeroacoustics algorithm that has been developed to predict forward noise radiation from such engines is described in this paper. The numerical algorithm is a 4th order accurate (both in space and time), Euler/Navier-Stokes solver that is written in essentially High Performance Fortran (HPF). The scheme uses the classical four-stage Runge-Kutta time integration, central differencing for spatial derivatives, and a blend of second and sixth order, Jameson type artificial dissipation to sup press high frequency numerical oscillations. On the outer boundaries of the computational domain, non-reflecting boundary conditions are used. Specifically the algorithm has been optimized for the CM-5 of Thinking Machines Corporation. An overlap ping mixture of the fluxes of the interior points and the far-field boundary points is established by making use of the MERGE statement which the programming languages, CM Fortran and Fortran 90, facilitate. This procedure leads to a simultaneous discretization of the spatial derivatives for the three different sets of governing equations across the domain: Navier-Stokes/Euler equations, radiation boundary conditions and outflow boundary conditions. Hence, approximately 60% reduction in computing the residuals of the governing equations is obtained on the Connection Machine computers. Results for a steady engine inlet flow, oscillating flat plate in a viscous fluid, scattering from a sphere, sound radiation from a baffled oscillating piston, and sound propagation through an axisymmetric inlet are presented.

AB - As transport aircraft engines get larger and larger, the dominant noise source component becomes the fan (forward and aft). A computational massively parallel aeroacoustics algorithm that has been developed to predict forward noise radiation from such engines is described in this paper. The numerical algorithm is a 4th order accurate (both in space and time), Euler/Navier-Stokes solver that is written in essentially High Performance Fortran (HPF). The scheme uses the classical four-stage Runge-Kutta time integration, central differencing for spatial derivatives, and a blend of second and sixth order, Jameson type artificial dissipation to sup press high frequency numerical oscillations. On the outer boundaries of the computational domain, non-reflecting boundary conditions are used. Specifically the algorithm has been optimized for the CM-5 of Thinking Machines Corporation. An overlap ping mixture of the fluxes of the interior points and the far-field boundary points is established by making use of the MERGE statement which the programming languages, CM Fortran and Fortran 90, facilitate. This procedure leads to a simultaneous discretization of the spatial derivatives for the three different sets of governing equations across the domain: Navier-Stokes/Euler equations, radiation boundary conditions and outflow boundary conditions. Hence, approximately 60% reduction in computing the residuals of the governing equations is obtained on the Connection Machine computers. Results for a steady engine inlet flow, oscillating flat plate in a viscous fluid, scattering from a sphere, sound radiation from a baffled oscillating piston, and sound propagation through an axisymmetric inlet are presented.

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M3 - Paper

AN - SCOPUS:84983158115

SP - 527

EP - 539

ER -