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Computation of interactional aerodyn...

Hennes, Christopher C.

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Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft./
Author:	Hennes, Christopher C.
Description:	294 p.
Notes:	Source: Dissertation Abstracts International, Volume: 75-06(E), Section: B.
Contained By:	Dissertation Abstracts International75-06B(E).
Subject:	Engineering, Aerospace. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3585582
ISBN:	9781303781797

Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft.
Hennes, Christopher C.

Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft. - 294 p.

Source: Dissertation Abstracts International, Volume: 75-06(E), Section: B.

Thesis (Ph.D.)--The Pennsylvania State University, 2013.

Many computational tools are used when developing a modern helicopter. As the design space is narrowed, more accurate and time-intensive tools are brought to bear. These tools are used to determine the effect of a design decision on the performance, handling, stability and efficiency of the aircraft. One notable parameter left out of this process is acoustics. This is due in part to the difficulty in making useful acoustics calculations that reveal the differences between various design configurations. This thesis presents a new approach designed to bridge the gap in prediction capability between fast but low-fidelity Lagrangian particle methods, and slow but high-fidelity Eulerian computational fluid dynamics simulations. A multi-pronged approach is presented. First, a simple flow solver using well-understood and tested flow solution methodologies is developed specifically to handle bodies in arbitrary motion. To this basic flow solver two new technologies are added. The first is an Immersed Boundary technique designed to be tolerant of geometric degeneracies and low-resolution grids. This new technique allows easy inclusion of complex fuselage geometries at minimal computational cost, improving the ability of a solver to capture the complex interactional aerodynamic effects expected in modern rotorcraft design. The second new technique is an extension of a concept from flow visualization where the motion of tip vortices are tracked through the solution using massless particles convecting with the local flow. In this extension of that concept, the particles maintain knowledge of the expected and actual vortex strength. As a post-processing step, when the acoustic calculations are made, these particles are used to augment the loading noise calculation and reproduce the highly-impulsive character of blade-vortex interaction noise. In combination these new techniques yield a significant improvement to the state of the art in rotorcraft blade-vortex interaction noise prediction.

ISBN: 9781303781797Subjects--Topical Terms:

1018395
Engineering, Aerospace.

Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft.
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100 1 $a Hennes, Christopher C. $3 3169079
245 1 0 $a Computation of interactional aerodynamics for noise prediction of heavy lift rotorcraft.
300 $a 294 p.
500 $a Source: Dissertation Abstracts International, Volume: 75-06(E), Section: B.
500 $a Adviser: Kenneth S. Brentner.
502 $a Thesis (Ph.D.)--The Pennsylvania State University, 2013.
520 $a Many computational tools are used when developing a modern helicopter. As the design space is narrowed, more accurate and time-intensive tools are brought to bear. These tools are used to determine the effect of a design decision on the performance, handling, stability and efficiency of the aircraft. One notable parameter left out of this process is acoustics. This is due in part to the difficulty in making useful acoustics calculations that reveal the differences between various design configurations. This thesis presents a new approach designed to bridge the gap in prediction capability between fast but low-fidelity Lagrangian particle methods, and slow but high-fidelity Eulerian computational fluid dynamics simulations. A multi-pronged approach is presented. First, a simple flow solver using well-understood and tested flow solution methodologies is developed specifically to handle bodies in arbitrary motion. To this basic flow solver two new technologies are added. The first is an Immersed Boundary technique designed to be tolerant of geometric degeneracies and low-resolution grids. This new technique allows easy inclusion of complex fuselage geometries at minimal computational cost, improving the ability of a solver to capture the complex interactional aerodynamic effects expected in modern rotorcraft design. The second new technique is an extension of a concept from flow visualization where the motion of tip vortices are tracked through the solution using massless particles convecting with the local flow. In this extension of that concept, the particles maintain knowledge of the expected and actual vortex strength. As a post-processing step, when the acoustic calculations are made, these particles are used to augment the loading noise calculation and reproduce the highly-impulsive character of blade-vortex interaction noise. In combination these new techniques yield a significant improvement to the state of the art in rotorcraft blade-vortex interaction noise prediction.
590 $a School code: 0176.
650 4 $a Engineering, Aerospace. $3 1018395
650 4 $a Physics, Acoustics. $3 1019086
650 4 $a Engineering, General. $3 1020744
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773 0 $t Dissertation Abstracts International $g 75-06B(E).
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