Explanipedia

Effect of sound source predicted by large eddy simulation on aerodynamic sound prediction of a box fan Open

Yuya MIKI, S. Uda, Yasumasa Suzuki, Chisachi KATO · 2024

In recent years, to predict the performance and the aerodynamic sound of box fans with high accuracy, numerical analysis has been necessary for the transitional boundary layer on the blades. In this study, two types of box fans with a base…

Benchmark tests of Flow solver based on Lattice Boltzmann Method on Fugaku Open

Yoshinobu Yamade, Chisachi KATO, Akiyoshi IIDA · 2023

Compressible LES Analysis of Unsteady Pressure Fluctuation in Centrifugal Blower Open

Kazuhiro Tsukamoto, Chisachi KATO · 2022

Large Eddy Simulation (LES) for compressible flow was conducted to analyze the pressure fluctuation at 17% of the impeller rotation frequency, which was confirmed at the impeller inlet and diffuser inlet under the operation condition on th…

Characteristics of aerodynamic noise radiated from a forward facing step with an incoming turbulent boundary layer Open

Yoshihiro SHIRASU, Yasumasa Suzuki, Yuya MIKI, Chisachi KATO · 2022

In this study, aerodynamic noise generates from forward step flow with different flow velocities U0 and step heights H were measured to investigate the characteristics of high-frequency wind noise generated from the Forward-Facing Step. Th…

Numerical Prediction of Aerodynamic Sound Radiated from a Box Fan using Computational Acoustic Analysis Open

Tomoki OIKAWA, Chisachi KATO, Yasumasa Suzuki · 2021

The far-field sound generated aerodynamically from a box fan is predicted by a computational aeroacoustics (CAA). The method is composed of the large eddy simulation of the incompressible fluid flow that computes the transitional boundary …

Influence of Grid Resolution on Flow Field and Aerodynamic Noise Prediction of Centrifugal Fan for Packaged Air Conditioner Open

Taku Iwase, Hideshi Obara, Yoshinobu Yamade, Chisachi KATO · 2020

In this study we calculated flow fields and aerodynamic noise in centrifugal fan of air conditioner by large eddy simulation (LES). The numerical simulation code employed throughout the LES was FrontFlow/blue (FFB). We compared calculation…

Preface Open

Shinnosuke Obi, Koji Fukagata, Masaharu Kameda, Chisachi KATO, Yohei MORINISHI , et al. · 2020

hosted by ASME Fluids Engineering Division.This four-year cycle stimulated international collaboration, bringing the global fluids engineering community together.

Prediction of Far Wake of a Two-dimensional Airfoil using the Large Eddy Simulation Open

Tatsuya Mizumoto, Yasumasa Suzuki, Chisachi KATO · 2020

The aim of this study was to investigate the vortex structure and the maximum vortex scale in the far wake of a two-dimensional NACA0012 airfoil. In order to estimate the maximum vortices scale, Large-Eddy Simulation (LES) for far wake of …

A study of aerodynamic sound generated from an airfoil placed in a flow with turbulence (2<sup>nd</sup> Report: In the case of airfoil subjected to circular-cylinder wake) Open

Noriaki Kobayashi, Yasumasa Suzuki, Chisachi KATO · 2020

To clarify the mechanism for aerodynamic sound to be generated from a lifting surface placed in a flow with turbulence, wind-tunnel experiments and numerical simulations have been carried out for a flow around an airfoil subjected to the w…

Computational aeroacoustics of aerodynamic sound generated by a box fan using the decoupled method Open

Yasumasa Suzuki, Chisachi KATO · 2020

In this study, numerical prediction of far field sound generated from a small box fan by using the decoupled method with large eddy simulation for incompressible flow and with computational aeroacoustics (CAA) in effect of sound reflection…

Analysis of blade-passage flow of a mixed-flow pump at performance-curve instability Open

Isao Hagiya, Chisachi KATO, Yoshinobu Yamade, Masashi Fukaya, Takahide Nagahara · 2019

To design a high-performance mixed-flow pump, performance-curve instability must be controlled and suppressed. To do this, the essential flow physics that leads to the performance-curve instability must be clarified in addition to an accur…

Fully-resolved large eddy simulation of transitional flow in inter-stage bush of a centrifugal pump Open

Romain Prunières, Chisachi KATO, Yoshinobu Yamade, Takahide Nagahara · 2019

When predicting the performances of a centrifugal pump by eddy-resolving computational fluid dynamics (CFD) methods such as Large-Eddy Simulation (LES), it is important that the phenomenon of interest and associated flow eddies are accurat…

Origin and formation process of a submerged vortex in a pump sump Open

Yoshinobu Yamade, Chisachi KATO, Takahide Nagahara, Jun Matsui · 2019

The origin and formation process of a submerged vortex have been fully clarified by large-eddy simulation (LES) that used approximately of 250 million hexahedral elements with maximum resolution of 0.450 mm and was applied to the internal …

Development, design, and manufacture in industries using supercomputer Fugaku Open

Chisachi KATO · 2019

LES Analysis for Incompressible Flow of Internal Flow in a Box Fan and Computational Aeroacoustics of Radiated Sound from It Open

Taku SHIRAFUJI, Yasumasa Suzuki, Chisachi KATO · 2019

In this study, it is clarified the influence of the total number and resolution of the computational grids on the accuracy of the numerical analysis by using the large eddy simulation for a small box fan. It is analyzed the accuracy by usi…

Formation mechanism of suction vortices in a pump sump Open

Yoshinobu Yamade, Chisachi KATO, Takahide Nagahara, Jun Matsui · 2019

The origin and formation mechanism of a submerged vortex and an air-entraining vortex have been fully clarified by large-eddy simulation (LES) that used approximately 2 billion hexahedral elements with maximum resolution of 0.255 mm and wa…

A study of aerodynamic noise and tip vortex formation on an oscillating airfoil Open

Yuichiro Watanabe, Chisachi KATO · 2019

To clarify the aerodynamic noise characteristics of an NACA0012 airfoil with a blunt wingtip by means of Large Eddy Simulation and Computational Aeroacoustics, we calculated the characteristic St numbers, which were 0.1, 0.3, and 0.5 for t…

Investigation of LES wall model using the result of the flat plate turbulent boundary layer Open

Yuya Miki, Chisachi KATO · 2019

In this study, we investigated the wall model for large eddy simulation by using flat plate boundary layer flow simulation. We conducted flow simulation by using different grid resolution, to find out the effect of grid resolution. We show…

Flow structure of a submerged vortex in a pump sump Open

Yoshinobu Yamade, Chisachi KATO, Takahide Nagahara, Jun Matsui · 2019

The flow structures of a submerged vortex that appears in a model pump sump have been fully clarified by performing large eddy simulation (LES) of a model vortex in a simplified computational model. The computational model had a sufficient…

Numerical Simulation of aerodynamic noise from an automobile by using acoustic perturbation equation Open

Akiyoshi IIDA, Hiroshi Yokoyama, Chisachi KATO · 2019

The most suitable method for aeroacoustics simulation is the direct method based on the compressible Naver-Storkes Equation. However, it is required a large amount of computational resources. The decomposition method of the aerodynamic noi…

Aerodynamic characteristics of wind turbines in tandem arrangement Open

Haruki IRITANI, Akiyoshi IIDA, Yoshinobu Yamade, Chisachi KATO · 2019

In order to estimate influence of wake interaction on power coefficient of offshore wind farms, large-scale numerical flow simulations were conducted with LES. The biggest issues of flow simulations for offshore wind farm is to solve the h…

Large eddy simulation of internal flow of single stage centrifugal pump Open

Yoshinobu Yamade, Hiroyoshi Watanabe, Chisachi KATO · 2019

Measurement of flow field and turbulence length scale in far wake of an airfoil Open

Yasumasa Suzuki, Chisachi KATO · 2019

In this paper, velocity distributions in the far wake to X/C=13.5 from the trailing edge of an NACA0012 airfoil flows are measured by using the hot-wire anemometer in wind tunnnel test. The Reynolds number based on the chord length of the …

A Study on Airfoil Flow and Aerodynamic Noise with Interaction of Vortices in Turbulent Flow and Boundary Layer around Airfoil Surface Open

Noriaki Kobayashi, Yasumasa Suzuki, Chisachi KATO · 2019

To clarify the mechanism for aerodynamic sound to be generated from an airfoil in a flow with turbulence, numerical simulations have been carried out for a flow around an airfoil subjected to the wake of a circular cylinder. The test airfo…

Unsteady blade-passage flows of a mixed-flow pump at performance-curve instability Open

Isao Hagiya, Chisachi KATO, Yoshinobu Yamade, Masashi Fukaya, Takahide Nagahara · 2018

For designing a high-performance mixed-flow pump, control and suppression of performance-curve instability is crucial. For doing so, clarification of the essential flow physics that leads to the performance-curve instability is crucial in …

Numerical Prediction of Flow around a Square Cylinder and Radiated Aerodynamic Sound by Using the Lattice Boltzmann Method Open

Satoru Namba, Tsubasa Koshitsuka, Yasumasa Suzuki, Chisachi KATO · 2018

In this paper, numerical results of flow around a square cylinder and of cavity flow by using Lattice Boltzman Method (LBM) are reported. The calculation is performed with a two models of D3Q15 and D3Q19 under Reynolds number of 140 for th…

The influence of computational grids on the accuracy for predicting performance and aerodynamic noise of a box fan by using the large eddy simulation Open

Taku SHIRAFUJI, Yasumasa Suzuki, Chisachi KATO · 2018

In this study, we clarify the influence of the total number and resolution of the computational grids on the accuracy of the numerical analysis by using the large eddy simulation for a small box fan. We analyze the accuracy by using four c…

Large-eddy simulation of flow around two off-shore wind turbines in tandem arrangement Open

Shori Orimo, Yoshinobu Yamade, Yasumasa Suzuki, Akiyoshi IIDA, Chisachi KATO · 2018

The wake of an upstream wind turbine decreases the output power of, and increases the fatigue load on the downstream wind turbines. It is therefore important to accurately evaluate the influence of the wake of the upstream turbines on the …

A Study on Airfoil Flow and Aerodynamic Noise in Vortex-Airfoil Interaction Open

Noriaki Kobayashi, Yasumasa Suzuki, K. Nishimura, Chisachi KATO · 2018

Recently, it has been a problem of aerodynamic noise radiated from airfoils. Therefore, the authors made wind tunnel tests to measure airfoil noise and static pressure on an airfoil (NACA0012 model) in turbulent flow. In additon, the autho…

Numerical investigations of submerged vortices in a model pump sump by using Large Eddy Simulation Open

Yoshinobu Yamade, Chisachi KATO, Takahide Nagahara, Jun Matsui · 2016

Submerged vortices in a model pump sump and their flow structures were investigated numerically. The model pump sump is composed of a 2,500 mm-long water channel with rectangular cross section of 150 mm (channel width) by 100 mm (water hei…

Chisachi KATO YOU? Author Swipe