Landing Gear Aerodynamic Noise Prediction Using Building-Cube Method

2011 ◽  
Author(s):  
Daisuke Sasaki ◽  
Hiroshi Onda ◽  
Akihito Deguchi ◽  
Ryotaro Sakai ◽  
Kazuhiro Nakahashi
Keyword(s):  
Landing Gear ◽  
Aerodynamic Noise ◽  
Noise Prediction

Near-Field Noise Prediction for Landing Gear Based on Detached Eddy Simulations

2014 ◽  
Vol 472 ◽  
pp. 105-110
Author(s):  
Ning Hu ◽  
Xuan Hao ◽  
Cheng Su ◽  
Wei Min Zhang ◽  
Han Dong Ma
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Sound Pressure ◽  
Near Field ◽  
Separated Flow ◽  
Landing Gear ◽  
Aerodynamic Noise ◽  
Noise Prediction ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

A four-wheel rudimentary landing gear is studied numerically by detached eddy simulation (DES) based on the Spalart-Allmaras turbulence model. The surface sound pressure level and sound pressure spectra are calculated using the obtained unsteady flow field. The investigation shows that DES can describe the steady and unsteady properties in the flow around rudimentary landing gear. It can give reasonable results since the flow around the landing gear is a massive separated flow. The results prove the feasibility of DES type methods in massive separated unsteady flow field and aerodynamic noise prediction for landing gear, and can be used in the study of landing gear noise reduction.

scholarly journals Landing Gear Aerodynamic Noise Prediction Using Building-Cube Method

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Daisuke Sasaki ◽  
Deguchi Akihito ◽  
Hiroshi Onda ◽  
Kazuhiro Nakahashi
Keyword(s):  
Large Scale ◽  
Building Blocks ◽  
Landing Gear ◽  
Experimental Result ◽  
Aerodynamic Noise ◽  
Noise Prediction ◽  
Computational Domain ◽  
Flow Solver ◽  
Flow Acceleration ◽  
Geometry Model

Landing gear noise prediction method is developed using Building-Cube Method (BCM). The BCM is a multiblock-structured Cartesian mesh flow solver, which aims to enable practical large-scale computation. The computational domain is composed of assemblage of various sizes of building blocks where small blocks are used to capture flow features in detail. Because of Cartesian-based mesh, easy and fast mesh generation for complicated geometries is achieved. The airframe noise is predicted through the coupling of incompressible Navier-Stokes flow solver and the aeroacoustic analogy-based Curle’s equation. In this paper, Curle’s equation in noncompact form is introduced to predict the acoustic sound from an object in flow. This approach is applied to JAXA Landing gear Evaluation Geometry model to investigate the influence of the detail components to flows and aerodynamic noises. The position of torque link and the wheel cap geometry are changed to discuss the influence. The present method showed good agreement with the preceding experimental result and proved that difference of the complicated components to far field noise was estimated. The result also shows that the torque link position highly affects the flow acceleration at the axle region between two wheels, which causes the change in SPL at observation point.

The effect of doors and cavity on the aerodynamic noise of fuselage nose landing gear

2021 ◽  
pp. 1475472X2110032
Author(s):  
Yongfei Mu ◽  
Jie Li ◽  
Wutao Lei ◽  
Daxiong Liao
Keyword(s):  
Separated Flow ◽  
Leading Edge ◽  
Landing Gear ◽  
Aerodynamic Noise ◽  
Sound Waves ◽  
Detached Eddy Simulation ◽  
Airframe Noise ◽  
Interference Phenomenon ◽  
Delayed Detached Eddy Simulation ◽  
The Doors

The aerodynamic noise of landing gears have been widely studied as an important component of the airframe noise. During take-off and landing, there are doors, cavity and fuselage around the landing gear. The noise caused by these aircraft components will interfere with aerodynamic noise generated by the landing gear itself. Hence, paper proposes an Improved Delayed Detached Eddy Simulation (IDDES) method for the investigation of the flow field around a single fuselage nose landing gear (NLG) model and a fuselage nose landing gear model with doors, cavity and fuselage nose (NLG-DCN) respectively. The difference between the two flow fields were analyzed in detail to better understand the influence of these components around the aircraft’s landing gear, and it was found that there is a serious mixing phenomenon among the separated flow from the front doors, the unstable shear layer falling off the leading edge of the cavity and the wake of the main strut which directly leads to the enhancement of the noise levels. Furthermore, after the noise sound waves are reflected by the doors several times, an interference phenomenon is generated between the doors. This interference may be a reason why the tone excited in the cavity is suppressed.

Mechanical and Aerodynamic Noise Prediction for Electric Vehicle Traction Motor and Its Validation

2017 ◽  
Author(s):  
Rahul Gurav ◽  
Kishor D Udawant ◽  
Ramkumar Rajamanickam ◽  
N V Karanth ◽  
S R Marathe
Keyword(s):  
Electric Vehicle ◽  
Aerodynamic Noise ◽  
Noise Prediction ◽  
Traction Motor

scholarly journals 1002 Aerodynamic noise reduction for aircraft landing gear

2009 ◽  
Vol 2009 (0) ◽  
pp. 321-322
Author(s):  
Kazuhide Isotani ◽  
Kenji Hayama ◽  
Akio Ochi ◽  
Toshiyuki Kumada
Keyword(s):  
Noise Reduction ◽  
Landing Gear ◽  
Aerodynamic Noise ◽  
Aircraft Landing ◽  
Aircraft Landing Gear

Numerical simulation of aeroacoustic noise from landing gear and rectangular cavity

2020 ◽  
Vol 234 (7) ◽  
pp. 1259-1271
Author(s):  
Zhifei Guo ◽  
Peiqing Liu ◽  
Jin Zhang ◽  
Hao Guo
Keyword(s):  
Numerical Simulation ◽  
Low Frequency ◽  
Landing Gear ◽  
Rectangular Cavity ◽  
Cavity Resonance ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
Radiation Mechanism ◽  
Ansys Fluent ◽  
Aeroacoustic Noise

This paper is aimed at researching the interaction between aeroacoustic noise radiated from a rectangular cavity (gear bay) and from landing gear. It is a complicated flow-induced noise problem, involving the nonlinear, unsteady evolution of the turbulent structure inside the airflow bypassing the landing gear and the cavity. The generation and radiation mechanism of aeroacoustic noise are also concerned. In fact, it is a problem about the nonlinear interaction between the vortices shedding from the boundary layer of bluff bodies and the cavity-limited shear layer. To simplify this issue, a two-wheel landing gear named LAGOON is chosen as the landing gear model. The unsteady flow field and aerodynamic noise from it is simulated by applying the commercial software ANSYS Fluent. Good agreement is achieved between the numerical simulation and wind tunnel measurements in terms of the aerodynamic and aeroacoustic results. According to the size of LAGOON, a simple rectangular cavity is designed as the landing gear bay. Both the cavity combined with LAGOON and the cavity alone are simulated and compared. The results show that under the blocking effect of a strut, most small pieces of vortices at the trailing edge of the cavity bottom would dissipate rather than move forward along with the backflow, leading to the correlation of cavity resonance being more contrasting and increasing its amplitude. The blockage effect induced by rear wall could also enhance the turbulence kinetic energy at the wake of the strut, thus increasing the low-frequency noise radiated from the strut and cavity.

A design‐oriented approach to landing gear noise prediction

2008 ◽  
Vol 123 (5) ◽  
pp. 3394-3394
Author(s):  
Philip J. Morris ◽  
Kenneth S. Brentner ◽  
Leonard V. Lopes
Keyword(s):  
Landing Gear ◽  
Noise Prediction ◽  
Gear Noise ◽  
Landing Gear Noise ◽  
Oriented Approach
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