检索结果-南通市图书馆

Journal of Thermal Science 2011年第3期20卷 238-241页

作者： Tsuyoshi Yasunobu Yumiko Otobe hideo kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology Sii Kokuraminami-ku Kitakyushu-shiFukuoka 802-0985 Japan

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow oscillation occurs at the specific condition of the pressure ratio in the flowfield, the position of an obstacle and so on. This oscillation is related with the noise problems of aeronautical and other industrial engineering so that the characteristic and the mechanism of self-induced flow oscillation have to be cleared to control the various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of oscillation have to be more clear to control the oscillation. This paper aims to clarify the effect of the plate position and the width for the self-induced flow oscillation of an underexpanded supersonic jet impinging on the perpendicular plate by the experiment and the numerical analysis. From the results, it is clear that the occurring domain of the self-induced flow oscillation and its dimension strongly depend on the plate position and the width.

关键词： Compressible Flow Supersonic Jet Mach Disk Barrel Shock Flow Oscillation

Characteristic and Mechanism of Pressure Fluctuation Caused by Self-Induced Oscillation of Supersonic Impinging Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2013年第2期22卷 123-127页

作者： Tsuyoshi Yasunobu Yumiko Otobe hideo kashimura Department of Control & Information Systems Engineering Kitakyushu College of Technology

When the underexpanded supersonic jet impinges on the obstacle, it is well known that the self-induced flow os- cillation occurs. This oscillation depends on the pressure ratio in the flowfield, the position of an obstacle and is related with the noise problems of aeronautical and other industrial engineering. The characteristic and the mechanism of self-induced flow oscillation, have to be clarified to control various noise problems. But, it seems that the characteristics of the oscillated flowfield and the mechanism of an oscillation have to be more cleared to control the oscillation. This paper aims to clarify the effect of the pressure ratio and the obstacle position and the mechanism of self-induced flow oscillation by numerical analysis and experiment, when the underexpanded su- personic jet impinges on the cylindrical body. From the result of this study, it is clear that occurrence of the self-induced flow osciUation depends on the pressure balance in the flowfield.

关键词： Supersonic Jet Mach Disk Barrel Shock Flow Oscillation Flow Visualization Numerical Analysis

Shock Wave in Supersonic Moist Air Jet for a Low Pressure Ratio

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第4期20卷 289-293页

作者： Yumiko OTOBE hideo kashimura Toshiaki SETOGUCHI Kitakyushu National College of Technology Saga University

In the present study,a computational fluid dynamics work was performed to investigate the occurrence of the shock wave by condensation in supersonic moist air *** unsteady,compressible axisymmetric Navier-Stokes equation is solved by TVD(Total Variation Diminishing) scheme in this *** numerical simulations have been performed for low pressure ratio and various *** results show the occurrence of the shock wave in supersonic moist air jet for a low pressure ratio when Mach disk does not occur,depending on humidity of the air.

关键词： compressible flow axisymmetric flow shock wave condensation humidity

Numerical Study for Hysteresis Phenomena of Shock Wave Reflection in Overexpanded Axisymmetric Supersonic Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2006年第3期15卷 220-225页

作者： Tsuyoshi Yasunobu Ken Matsuoka hideo kashimura ShigeruMatsuo ToshiakiSetoguchi Corresponding Author Department of Control and Information Systems EngineeringKitakyushuCollege of Technology5-20-1 ShiiKokuraminamiKitakyushuJapan Kitakyushu College of Technology 5-20-1 ShiiKokuraminamiKitakyushuJapan(Student) Kitakyushu College of Technology 5-20-1 ShiiKokuraminamiKitakyushuJapan Department of Mechanical Engineering Saga University1HonjoSagaJapan

When the high-pressure gas is exhausted to the vacuum chamber from the supersonic nozzle, the overexpanded supersonic jet is formed at specific condition. In two-dimensional supersonic jet, furthermore, it is known that the hysteresis phenomena for the reflection type of shock wave in the flow field is occurred under the quasi-steady flow and for instance, the transitional pressure ratio between the regular reflection （RR） and Mach reflection （MR） is affected by this phenomenon. Many papers have described the hysteresis phenomena for underexpanded supersonic jet, but this phenomenon under the overexpanded axisymmetric jet has not been detailed in the past papers. The purpose of this study is to clear the hysteresis phenomena for the reflection type of shock wave at the overexpanded axisymmetric jet using the TVD method and to discuss the characteristic of hysteresis phenomena.

关键词： compressible flow axisymmetric flow supersonic jet regular reflection Mach reflection

Numerical Analysis of Turbulent Sonic Jets from Two-Dimensional Convergent Nozzles

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2011年第2期20卷 133-138页

作者： hideo kashimura Yuya MASUDA Yoshiaki MIYAZATO Kazuyasu MATSUO Department of Control and Information Systems Engineering Kitakyushu National College of Technology 5-20-1ShiiKokuraminami-kuKitakyushuFukuoka802-0985JAPAN Department of Mechanical Systems Engineering The University of Kitakyushu1-1HibikinoWakamatsu-kuKitakyushuFukuoka808-0135JAPAN

The numerical analysis of a turbulent sonic jet from a two-dimensional convergent nozzle has been carried out using the compressible k-? turbulence model and TVD finite difference scheme. Numerical conditions have been varied over a range of operating pressure ratios from 1.893 to 6.0 which cover the jet flow conditions from correctly expanded to underexpanded. Numerical flow visualization of sonic jet structure using the computer schlieren, a relation between shock cell length in the jet with the operating pressure ratio and the pressure distribution along jet centerline are obtained. Also, a transition process of a two-dimensional sonic jet from correctly expanded to underexpanded conditions is shown in detail and a flow model of jet structure is proposed.

关键词： Sonic nozzle Underexpanded jet Shock cell length κ-ε turbulence model Numerical analysis

Generation of Overpressure due to Condensation in Moist Air Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第2期16卷 145-148页

作者： Yumiko OTOBE hideo kashimura Shigeru MATSUO Masanori TANAKA Toshiaki SETOGUCHI Kitakyushu National College of Technology 5-20-1 ShiiKokuraminamiKitakyushuJapan Saga University 1HonjoSagaJapan

In the present study, a computational fluid dynamics method has been applied to investigate the effects of initial degree of supersaturation at reservoir condition on under-expanded sonic jet structures, such as Mach disk location and diameter, barrel shock wave and jet boundary. The axisymmetric nozzle geometry investigated was a converging nozzle with straight part. As a result, it was found that the overpressures due to condensation generate and the characteristics of flow with generation of overpressure due to condensation in the jet were different from those without condensation.

关键词： compressible flow axisymmetric flow sonic jet Mach disk condensation humidity overpressure

A Study of Under-expanded Moist Air Jet Impinging on a Flat Plate

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2005年第4期14卷 334-340页

作者： Yumiko OTOBE Shigeru MATSUO Masanori TANAKA hideo kashimura Heuy-Dong KIM Toshiaki SETOGUCHI Department of Control and Information Systems Engineering Kitakyushu National College of Technology5-20-1ShiiKokuraminami-kuKitakyushu-shiFukuoka 802-0985Japan Department of Mechanical Engineering Saga University1Honjo-machiSaga-shiSaga 840-8502Japan School of Mechanical Engineering College of Natural ScienceAndong National University388Song Cheon DongAndongKyung PookKorea

When a gas expands through a convergent nozzle in which the ratio of the ambient to the stagnation pressures is higher than that of the critical one, the issuing jet from the nozzle is under-expanded. If a flat plate is placed normal to the jet at a certain distance from the nozzle, a detached shock wave is formed at a region between the nozzle exit and the plate. In general, supersonic moist air jet technologies with non-equilibrium condensation are very often applied to industrial manufacturing processes. In spite of the importance in major characteristics of the supersonic moist air jets impinging to a solid body, its qualitative characteristics are not known satisfactorily. In the present study, the effect of the non-equilibrium condensation on the under-expanded air jet impinging on a vertical flat plate is investigated numerically in the case with non-equilibrium condensation, frequency of oscillation for the flow field becomes larger than that without the non-equilibrium condensation, and amplitudes of static pressure become small compared with those of dry air. Furthermore, the numerical results are compared with experimental ones.

关键词： compressible flow non-equilibrium condensation impinging jet simulation.

Effect of Axisymmetric Sonic Nozzle Geometry on Characteristics of Supersonic Air Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2004年第2期13卷 121-126页

作者： Shigeru MATSUO Masanori TANAKA Yumiko OTOBE hideo kashimura Heuy-Dong KIM Toshiaki SETOGUCHI Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan Department of Control and Information Systems Engineering Kitakyushu National College of Technology 5-20-1 Shii Kokuraminami-ku Kitakyushu-shi Fukuoka 802-0985 Japan School of Mechanical Engineering College of Natural Science Andong National University 388 Song-Cheon Dong Andong Kyung-Pook Korea

The effect of nozzle geometry on sonic line and characteristics of supersonic air jet was studied. Computational fluid dynamics was applied in this study. The axisymmetric nozzle geometries investigated were two different contour converging nozzles, two different conically converging sharp-edged nozzles and a sharp-edged orifice. The results show that the supersonic jet structure, sonic line and streamlines in supersonic jet are strongly influenced by the nozzle geometry, and the total pressure loss increases with the increase of Mach disk diameter. The present numerical simulation is an effective tool to evaluate compressible flows in supersonic air jet.

关键词： compressible flow supersonic jet non-equilibrium condensation simulation.

Characteristics of Spherical Shock Wave and Circular Pulse Jet Generated by Discharge of Propagating Shock Wave at Open End of Tube

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第3期12卷 245-249页

作者： Tsukasa Irie Tsuyoshi Yasunobu hideo kashimura Toshiaki Setoguchi Kazuyasu Matsuo Department of Mechanical Engineering Kitakyushu National College of Technology ShiiKokuraminami-ku Kitakyushu 802-0985 Japan Department of Control and Information Systems Engineering Kitakyushu National College of Technology Shii Kokuraminami-ku Kitakyushu 802-0985 Japan Department of Mechanical Engineering Saga University Honjo Saga 840-8502 Japan Department of Mechanical Systems and Environmental Engineering Univ. of Kitakyushu1-1 Hibikino Wakamatsu-ku Kitakyushu808-0135 Japan

When the shock wave propagating in the straight circular tube reaches at the open end, the impulsive wave is generated by the emission of a shock wave from an open end, and unsteady pulse jet is formed near the open end behind the impulsive wave under the specific condition. The pulse jet transits to spherical shock wave with the increase in the strength of shock wave. The strength is dependent on the Mach number of shock wave, which attenuates by propagation distance from the open end. In this study, the mechanism of generating the unsteady pulse jet, the characteristics of the pressure distribution in the flow field and the emission of shock wave from straight circular tube which has the infinite flange at open end are analyzed numerically by the TVD method. Strength of spherical shock wave, relation of shock wave Mach number,distance decay of spherical shock wave and directional characteristics are clarified.

关键词： shock wave impulsive wave numerical analysis spherical shock wave TVD method

Discharge of a Shock Wave from an Open End of a Tube

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2000年第1期9卷 30-36页

作者： hideo kashimura Tsuyoshi Yasunobu Hiroyasu Nakayama Toshiaki Setogucki Kazuyasu Matsuo Department of Control and Information Systems Engineering Kitakyushu National College of Technology5-20-1ShiiKokuraminami-kuKiatakyushu-shiFukuoka 802-0985 Japan

When a Pressure wave propagates along a constant area straight tube and reaches at the open end, an impulsive wave is emitted outward from the tube exit toward the surrounding area and causes an impulsive noise like a sonic boom. In order to clarify the magnitude of an impulsive wave obtained by the discharge of a weak shock wave born an open end of a tube in relation to the noise problem and the industrial devices, the experimental and numerical investigations have been carried out for various strength of a shock wave. A simple open end shock tube with the flange at the tube *** used and the numerical calculation using the TVD scheme was performed. The effective equations which concerns with the magnitude of an impulsive wave generated by the emission of a shock wave have been obtained from the procedure of the open end correction based on the aeroacoustic theory and the numerical results. The influence of open end correction length and the diameter of a flange on the magnitude of an impulsive wave has been discussed.

关键词： compressible flow unsteady flow shock wave impulsive wave aeroacoustic theory.