Aeroacoustic measurements associated with noise radiation from the leading edge slat of canonical, unswept 30P30N three-element high-lift airfoil configuration have been obtained in a 2 m x hard-wall wind tunnel at Japan Aerospace Exploration Agency (JAXA). Performed as part collaborative effort on airframe between JAXA and National Aeronautics Space Administration (NASA), model geometry majority instrumentation details are identical to NASA exception larger span. For an angle attack up 10...

The purpose of this study is to design noise reduction devices for leading-edge slat which called as a cove filler (SCF), from both aerodynamic and acoustic points view. From the previous studies, SCF seems have an effect on reducing broadband by forming substantially continuous shape instead cusp configuration. However, there are some studies indicate decrease performance when attached. Since primary feature high-lift-devices increase performance, maximum lift coefficient or stall angle...

To obtain detailed validation data for a complicated high-lift system including aerodynamics, aeroacoustics, flow visualization, and so on, half-span large-scale high lift device model was tested in JAXA 6.5m x 5.5m Low-speed Wind Tunnel. Five-component aerodynamic force aeroacoustic noise with phased array microphones were measured simultaneously, surface pressure taps Pressure Sensitive Paint (PSP), unsteady using mounted sensors, velocity distribution around the Particle Image Velocimetry...

Airframe noise generation at the flap-edge is investigated on a simplified three elements high-lift configuration wing model. Lowspeed wind tunnel experiments for aerodynamics measurements in JAXA-LWT2 and Large scale anechoic facility of Railway Technical Research Institute as well steady-state Reynolds-Average NavierStokes computation (RANS) has been implemented. Cross spectrum analysis computational results connect far-field near-field unsteadiness, then show mechanism around flap-edge....

This paper deals with results of noise measurements for a 40% two-wheel type aircraft main landing gear in lowspeed wind tunnel experiments. In order to accurately assess source location and far-field characteristics during the approach phase, scale model complex geometry which was equipped small components such as link mechanism, hydraulic tubes electrical wiring well tire, cylinder, piston, doors, sidebrace used. Model based on LEG (Landing Evaluation Geometry) designed by manufacturer...

This paper describes new anechoic closed test sections in Japan Aerospace Exploration Agency (JAXA) and Virginia Tech (VT) not only for an aeroacoustic but also aerodynamic testing ability Low-speed wind tunnels. The section with Kevlar wall is innovative concept had been originally developed at VT. It was later applied to JAXA’s 2m x tunnel. By using a high-lift device model, the JAXA's evaluated validated acoustically by comparing VT results. Moreover, characteristics were results of same...

In this study, the propagation time and attenuation rate distributions of each sound source grid point (200 × 200) to a microphone an arbitrary position across shear layer, which are required for beamforming, were reconstructed by reduced-order model with sparse sampling acceleration computation. First, distributions, including refraction layer calculated over 100 patterns combinations wind speed position, as training data. The dominant modes optimum points discovered from Subsequently,...

This paper presents computational and experimental studies on the flap side-edge noise using a three-element rectangular high-lift wing model with full-span slat part-span for device research in JAXA. The main purpose of this is focused numerical investigation change flowfield far-field by sideedge shapes. Several configurations rounded side-edges, cavity side-edge, protruding-type lower surface are investigated paper. By computations wind tunnel tests, mechanisms generation reduction discussed.

In this paper, noise generation from high-lift devices (HLDs) of a sweptand taperedwing model OTOMO2 measured in low speed wind tunnel experiments are discussed. has wing section simplified configuration rectangular OTOMO, and also planform realistic aircraft JSM. Main purpose the experiment was to answer questions about influence geometry on HLD noise, which remained our previous research using OTOMO. Results far-field measurement RTRI-Maibara source maps obtained JAXA-LWT2 mainly used....

To investigate airframe noise from high lift devices, acoustic measurement was carried out at JAXA 2m x Low-speed Wind Tunnel (LWT2) and Large-Scale Anechoic in Railway Technical Research Institute (RTRI) by using a simplified three-element wing model. Noise around slat, tip flap side edge were observed as dominant of this model results phased-array microphone measurement. The ratio each spectrum to overall investigated source evaluated comparison far-field spectra with integration value...

The aeroacoustic measurement using a half-span aircraft model equipped with high lift devices was carried out for the first time in JAXA 6.5m x 5.5m low speed wind tunnel. As result of this test, noise sources located at main wing tip, slat tracks, flap slat-pylon region and so on are observed. generated from tip outboard had strong dependence Reynolds number angle attack. However, tracks didn’t have neither nor In paper, phased array system is introduced, then results measurements presented.

This study proposes a framework that reduces the calculation cost of sound source localization with Amiet model, using data-driven sparse sampling method. method accelerates steering vector used in conventional beamforming. An aeroacoustic wind tunnel test was conducted 2 × m2 low-speed tunnel, and proposed verified. During test, monopole laser source, which does not interfere flow, used, its acoustic signals were measured microphone array. Next, vectors reconstructed by discovering dominant...

This research deals with a kind of parametric excitation permanent magnet freely levitated above high-T/sub c/ superconductor excited in the vertical direction. We find has two vibration modes linearly coupled horizontal translation and roll motion. These are nonlinearly motion by magnetic force torque. Through nonlinear analysis numerical simulation, this discusses resonance each mode caused at frequency neighborhood twice natural that mode. Analytical results show qualitative agreement...

In order to reduce aerodynamic noise from aircraft flap tip, we design two types of low tips named “Small Barrier” and “Leading Edge Cut”. The former has small cubes on the upper surface near leading edge at tip. latter cut which location is moved backward. Both are designed induce flow separation surface. It takes a reduction lift around Then, it makes tip vortexes weaker causes noise. Other aspect design, focused usefulness apply them actual aircrafts. shape so simple that weight penalty...

This paper focuses on numerical and experimental research for designing low-noise slat a simplified high-lift configuration model (OTOMO). Two types of noise reduction devices are considered. First device is cove filler (SCF). From the previous studies, SCF seems to have an effect reducing broadband by forming substantially continuous shape instead cusp configuration. Several different geometries designed tested experimentally as well numerically. The second called thin (TS). maintains...

As using NACA 0012 quasi-2-dimensional wing model, noise measurements, flow-visualization and transition measurements were conducted in JAXA 2m x Low-speed Wind Tunnel. The relationship between generation flow field around the model such as separation, unsteady velocity was investigated utilizing hot-films, oil-flow visualization, Preston tube method china- clay for surface on airfoil with tip. results, it made clear that generated at a region where effective angle of attack corresponded an...