Ryoyu Systems Co.

Nagoya-shi, Japan

Ryoyu Systems Co.

Nagoya-shi, Japan
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Tanabe Y.,Japan Aerospace Exploration Agency | Sugawara H.,Ryoyu Systems Inc. Ltd.
5th Asian-Australian Rotorcraft Forum, ARF 2016 | Year: 2016

A numerical simulation of the rotor/wing aerodynamic interaction in hover using rotorcraft CFD solver, rFlow3D, is described. The wing download caused by the rotor downwash is studied under various rotor thrust, with and without wing flap and at different distances between the rotor and the wing, and the results are compared with the experimental data by NASA. The computational results of wing download are overestimated, but the trends are predicted qualitatively in good agreement with the experimental data except in the case of distance between the rotor and the wing. The rotor performance changes due to the wing are predicted in good agreement with the ground effect with consideration of rotor and wing area ratio. Copyright © 2016 by the American Helicopter Society International, Inc. All rights reserved.


Murayama M.,Japan Aerospace Exploration Agency | Yamamoto K.,Japan Aerospace Exploration Agency | Yokokawa Y.,Japan Aerospace Exploration Agency | Ito Y.,Japan Aerospace Exploration Agency | And 3 more authors.
23rd AIAA/CEAS Aeroacoustics Conference, 2017 | Year: 2017

This paper focuses on noise reduction design for flap side-edges toward the 1st flight demonstration using JAXA’s experimental research aircraft, “Hisho”, which is based on the business jet Cessna Model 680 in a flight demonstration project for airframe noise reduction technology, FQUROH (Flight demonstration of QUiet technology to Reduce nOise from High-lift configurations). This paper presents the design efforts using CFD and wind tunnel test on two of the three flap noise reduction designs; (1) protruding rounded lower-edge for lower side of the flaps and (2) vortex generators for upper side of the flaps. The first demonstration flight was conducted in September 2016, and the sound pressure level around the flap edges was successfully reduced as expected except for at several frequency bands. The difference between the predicted results and the flight test result was also discussed. © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


Murayama M.,Japan Aerospace Exploration Agency | Yamamoto K.,Japan Aerospace Exploration Agency | Takaishi T.,Japan Aerospace Exploration Agency | Ito Y.,Japan Aerospace Exploration Agency | And 4 more authors.
23rd AIAA/CEAS Aeroacoustics Conference, 2017 | Year: 2017

In this study, a practical noise reduction concept using vortex generators is proposed to reduce airframe noise from flap side-edge. The effectiveness of the concept is investigated by CFD and wind tunnel tests using a high-lift wing noise research model in JAXA. The influence of the setting parameters of vortex generators on the noise reduction is investigated through the computational and experimental studies. The effectiveness of combination of two noise reduction concepts using current vortex generators for upper side of flaps and protruding rounded lower-edge, PRLE, for lower side proposed earlier is also evaluated. The results showed that noise reduction effects of overall sound pressure level were around 1.5 dB(A) only with vortex generators, around 2.0dB(A) only with PRLE, and around 4.0 dB(A) with combination of PRLE and vortex generators. © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


Ito Y.,Japan Aerospace Exploration Agency | Murayama M.,Japan Aerospace Exploration Agency | Yamamoto K.,Japan Aerospace Exploration Agency | Tanaka K.,Ryoyu Systems Co.
23rd AIAA Computational Fluid Dynamics Conference, 2017 | Year: 2017

This paper describes a computational fluid dynamics aerodynamic analysis performed in preparation for a preliminary flight test in an airframe noise reduction technology flight demonstration project called FQUROH (Flight demonstration of Quiet technology to Reduce Noise from High-lift configurations). High-fidelity Reynolds-averaged Navier-Stokes simulations were conducted with an unstructured flow solver, the TAS code, and a hybrid mesh generator, MEGG3D, to design wind tunnel models of the Japan Aerospace Exploration Agency’s Jet Flying Test Bed, “Hisho,” based on a Cessna Citation Sovereign, and to evaluate the aerodynamic performance of low-noise modifications for Hisho under actual flight conditions in order to preclude aerodynamically questionable designs. Computational methods are described with several actual examples. © 2017, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


Okada K.,Yokohama National University | Okada K.,Ryoyu Systems Co. | Oyama A.,Japan Aerospace Exploration Agency | Fujii K.,Japan Aerospace Exploration Agency | Miyaji K.,Yokohama National University
Transactions of the Japan Society for Aeronautical and Space Sciences | Year: 2012

This paper investigates the effects of nondimensional parameters on the characteristics of synthetic jets. Flow inside the synthetic jet cavity and orifice, the flow outside are simulated together using large-eddy simulations (LES). A comparison of the present results and those of the experiment shows that simulating the flow both inside and outside the jet cavity is essential for accurately estimating the velocity and velocity fluctuations of the synthetic jet. LES results under various flow conditions show that strong three-dimensional vortices are generated when the Reynolds number is large, but finer vortex structures form because of stronger vortex interaction as the Strouhal number increases. © 2012 The Japan Society for Aeronautical and Space Sciences.


Yamamoto K.,Japan Aerospace Exploration Agency | Tanaka K.,Ryoyu Systems Co. | Murayama M.,Japan Aerospace Exploration Agency
30th AIAA Applied Aerodynamics Conference 2012 | Year: 2012

This paper presents an improvement in numerical prediction of aerodynamic characteristics for transonic commercial aircraft using the Reynolds-averaged Navier-Stokes equations. With turbulence models base on the Boussinesq eddy-viscosity approximation, the shock-induced flow-separation at wing-body juncture-corner is sometimes overestimated at higher angle-of-attack, which often results in wrong prediction of aerodynamic force and moment of aircraft. To improve it, we focus on effect of anisotropy in the Reynolds stress at the corner flow. A simple nonlinear constitutive relation is employed to introduce the anisotropy of the Reynolds stress for the turbulence models. The obtained results show that the size of the flow separation considerably shrinks with the nonlinear model and fairly good comparison with experimental results. The detailed flow in boundary-layer at the corner is discussed for better understanding of physics that results in the improvement of prediction. © 2012 by Kazuomi Yamamoto.


Oe H.,Tokyo University of Science | Yamamoto M.,Tokyo University of Science | Tanabe Y.,Japan Aerospace Exploration Agency | Sugawara H.,Ryoyu Systems Co.
34th Wind Energy Symposium | Year: 2016

This work presents the results of coupled analysis of CFD simulation of a 10MW class three-bladed rigid wind turbine with an Individual Pitch Control (IPC) system in stable Atmospheric Boundary Layer (ABL) condition without turbulence. A CFD/CSD coupling analysis code rFlow3D, developed in Japan Aerospace Exploration Agency (JAXA) originally for rotorcraft, is applied to this computation. The IPC system is a load-based feedback type, which can continuously control the pitch angle of each blade in a rated rotational frequency. This study intends to quantitatively verify the aerodynamic IPC effect for reducing fatigue load on the wind turbine which is exposed to ABL utilizing high fidelity simulation tool. For normal lift force and blade root flapwise moment, the control system effectively reduces dominant 1P fluctuation, which are caused by ABL, by 94%. 2P and higher fluctuations of blade root edgewise moment are also mitigated by more than 90% by the control effect. EFLs (Equivalent Fatigue Load) for the blade root moments are therefore largely mitigated due to the control while that for each rotor yaw and tilt moment slightly increase. These obtained results suggest that the IPC system can be sufficiently computed using CFD technique and indicate the effectiveness of IPC system to lower fatigue load on wind turbines. © 2016 American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.


Tanabe Y.,Japan Aerospace Exploration Agency | Sugawara H.,Ryoyu Systems Co.
41st European Rotorcraft Forum 2015, ERF 2015 | Year: 2015

Validation of the rFlow3D code developed at Japan Aerospace Exploration Agency (JAXA) has been carried out with the published UH-60A test data in hover and forward flight. Also, the slowed rotor conditions are simulated to investigate the applicability of this code at high advance ratios. Although the elastic deformation of the blade is not considered at this point, good agreement of the aerodynamic performance is obtained compared with the experimental data. Extensions of the CFD solver toward complete compound helicopter simulations are also discussed.


Yamamoto K.,Japan Aerospace Exploration Agency | Yamamoto K.,Aviation Program Group | Tanaka K.,Japan Aerospace Exploration Agency | Tanaka K.,Ryoyu Systems Co. | And 2 more authors.
28th AIAA Applied Aerodynamics Conference | Year: 2010

Comparison study of computations for the 4th AIAA CFD Drag Prediction Workshop (DPW-IV) is performed on the NASA Common Research Model using the structured grid solver UPACS and the unstructured grid solver TAS-code. The results on the all test cases of DPW-IV (Grid convergence, Downwash, Mach sweep and Reynolds number studies) are shown and sensitivity of the drag prediction by the two different mesh methods is discussed. Additional discussion including the effect of grid resolution and the anisotropic Reynolds stress tensor on the flow separation at wing-body juncture corner for higher angle of attack and its influence on the aerodynamic performance is also described. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.


Murayama M.,Japan Aerospace Exploration Agency | Yokokawa Y.,Japan Aerospace Exploration Agency | Yamamoto K.,Japan Aerospace Exploration Agency | Hirai T.,Ryoyu Systems Co.
Computers and Fluids | Year: 2013

The purpose of this paper is computational investigation of flowfield related to two types of low noise devices for noise from tire-axle region of a two-wheel main landing gear. The detailed unsteady flowfield around complicated geometry of tire-axle regions and its relation to noise generation are identified by unsteady CFD computations for the baseline configuration without low-noise devices. Then, the changes of flow structure related to possible noise sources by two types of low-noise fairings using solid surface and porous surface around the tire-axle region are clarified by steady CFD computations. By the computations, the design knowledge of low noise fairings around tire-axle region of a two-wheel main landing gear is investigated. © 2012 Elsevier Ltd.

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