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Passive Control of Condensation Shock Wave in Prandtl-Meyer Expansion Flow

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Journal of Thermal Science 2003年第1期12卷 20-26页

作者： Shigeru matsuo Masanori Tanaka Toshiaki Setoguchi Heuy-Dong Kim Department of Mechanical Engineering Saga UniversityDepartment of Mechanical Engineering Saga UniversityDepartment of Mechanical Engineering Saga UniversitySchool of Mechanical Engineering College of Natural Science Andong National University 388 1 Honjo-machi Saga-shi Saga 840-8502 Japan1 Honjo-machi Saga-shi Saga 840-8502 Japan 1 Honjo-machi Saga-shi Saga 840-8502 Japan Song-Cheon Dong Andong Kyung-Pook Korea

In this paper, the effects of the passive technique by using the slotted wall on the characteristics of a condensation shock wave generated in a Prandtl-Meyer flow were investigated experimentally. Furthermore, in order to clarify the variation of condensation properties in the flow field, Navier-Stokes equations were solved numerically using a 3rd-order MUSCL type TVD finite-difference scheme with a second-order fractional-step for time integration. Baldwin-Lomax model was used as a turbulence model in the computations. From experimental results, it was found that the shock strength on the slotted wall became weak in comparison with no passive case (solid wall), and the present passive technique was the most effective when a foot of the condensation shock wave was located at the middle of slotted wall. Furthermore, it was confirmed numerically that the passive technique was also effective for the unsteady condensation shock wave.

关键词： compressible flow Prandtl-Meyer flow condensation shock wave numerical simulation.

A Computational Study of Thrust Vectoring Control Using Dual Throat Nozzle

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Journal of Thermal Science 2010年第6期19卷 486-490页

作者： Choon Sik Shin Heuy Dong Kim Toshiaki Setoguchi Shigeru matsuo Department of Mechanical Engineering Andong National University Department of Mechanical Engineering Saga University

Dual throat nozzle (DTN) is fast becoming a popular technique for thrust vectoring. The DTN is designed with two throats, an upstream minimum and a downstream minimum at the nozzle exit, with a cavity in between the upstream throat and exit. In the present study, a computational work has been carried out to analyze the performance of a dual throat nozzle at various mass flow rates of secondary flow and nozzle pressure ratios (NPR). Two-dimensional, steady, compressible Navier-Stokes equations were solved using a fully implicit finite volume scheme. The present computational results were validated with available experimental data. Based on the present results, the control effectiveness of thrust-vectoring is discussed in terms of the thrust coefficient and the coefficient of discharge.

关键词： Compressible Flow Dual Throat Nozzle Thrust Vector Control Shock Wave Supersonic Flow

Control of Transonic Flow Fields Using Local Occurrence of Non-Equilibrium Condensation

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Journal of Thermal Science 2013年第4期22卷 327-332页

作者： Junji Nagao Shigeru matsuo Tokitada Hashimoto Toshiaki Setoguchi Heuy Dong Kim Department of Advanced Technology Fusion Saga University Institute of Ocean Energy Saga University School of Mechanical Engineering Andong National University

Control of supersonic flow fields with shock wave is important for some industrial fields. There are many studies for control of the supersonic flow fields using active or passive control. When non-equilibrium condensation occurs in a supersonic flow field, the flow is affected by latent heat released. Many studies for the condensation have been conducted and the characteristics have been almost clarified. Further, it was found that non-equilibrium condensation can control the flow field. In these studies, the condensation occurs across the passage of the flow field and it causes the total pressure loss in the flow field. However, local occurrence of non-equilibrium condensation in the flow field may change the characteristics of total pressure loss compared with that by the condensation across the passage of the nozzle and there are few for researches of locally occurred non-equilibrium condensation in supersonic flow field. The purpose in the present study is to clarify the effect of local occurrence of non-equilibrium condensation on the transonic flow field in a nozzle with a circular bump. As a result, local occurrence of non-equilibrium condensation reduced the shock strength and total pressure loss in the transonic flow field by flowing the moist air from trailing edge of the circular bump to the mainstream.

关键词： Compressible flow Transonic flow Shock wave Non-equilibrium condensation Circular bump

Unsteady Shock-Flow Characteristics in an Over-Expanded Rocket Nozzle

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Journal of Thermal Science 2010年第4期19卷 332-336页

作者： Jong Sung Lee Huey Dong Kim Toshiaki Setoguchi Shigeru matsuo School of Mechanical Engineering Andong National UniversityAndong760-749Korea Department of Mechanical Engineering Saga University1HonjoSagaJapan

A numerical investigation of transient side-loads in an axisymmetric over-expanded thrust optimized contour nozzle is *** nozzles experience side-loads during start-up and shut-down operations,because of the flow separation at nozzle *** types of flow separations such as FSS and RSS shock structure occur.A two-dimension numerical simulation has been carried out over an axisymmetric TOC nozzle to validate present results and investigate oscillatory flow characteristics for start-up *** Averaged Navier-Stokes equations are numerically solved using a fully implicit finite volume *** equations are solved by coupled implicit *** Stress turbulence model is *** computed pressure at the nozzle wall closely matched with experiment data.A hysteresis phenomenon has been observed between these two shock *** transition from FSS to RSS pattern during start-up process has shown maximum nozzle wall *** wall pressure and shear stress values have shown fluctuations during the FSS to RSS transition. The oscillatory pressure has been observed on the nozzle wall for high pressure *** results have shown that magnitude of the nozzle wall pressure variation is high for the oscillatory phenomenon.

关键词： Free shock separation Over-expansion flow Restricted shock separation Side-loads Supersonic nozzle

Generation of Overpressure due to Condensation in Moist Air Jet

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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

Generating and Focusing of Underwater Expansion Wave using a Silicon Resin Reflector

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Journal of Thermal Science 2013年第3期22卷 209-215页

作者： Takafumi Nakabaru Tokitada Hashimoto Shigeru matsuo Toshiaki Setoguchi G.Rajesh Graduate School of Science and Engineering Saga University Department of Advanced Technology Fusion Graduate School of Science and Engineering Saga University Institute of Ocean Energy Saga University Keimyung University

In the present study, an ellipsoid reflector was designed and produced using silicon resin in order to generate and focus expansion wave in water for the purpose of a medical application. Across an expansion wave the static pressure, temperature and density decrease, as a result, negative pressure is given behind the expansion wave generated in the water, and then a tensile stress is induced. As an acoustic impedance of the silicon resin is almost similar to that of water, the interface of air-silicon resin would be regarded as the same with that of the air-water. A high voltage discharge was used as an energy source of underwater shock wave. When the underwater shock wave reflects on this interface, it is already clear that the shock wave converts to the expansion wave. The generation and focusing of the expansion wave were carried out and the phenomena were observed by flow visualization using a high-speed camera.

关键词： medical application, under water expansion wave, focusing technique, acoustic impedance

Antithrombin reduces reperfusion-induced hepatic metastasis of colon cancer cells

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World Journal of Gastroenterology 2006年第1期12卷 60-65页

作者： Masanao Kurata Kenji Okajima Toru Kawamoto mitsuhiro Uchiba Nobuhiro Ohkohchi Department of Surgery Functional and Regulatory Medical SciencesGraduate School of Comprehensive Human SciencesUniversity ofTsukubaTsukubaJapan Department of Biodefense Graduate School of Medical SciencesNagoya City UniversityNagoyaJapan Department of Diagnostic Medicine Graduate School of Medical SciencesKumamoto UniversityKumamotoJapan

AIM： To examine whether antithrombin （AT） could prevent hepatic ischemia/reperfusion （I/R）-induced hepatic metastasis by inhibiting tumor necrosis factor （TNF）-α-induced expression of E-selectin in rats. METHODS： Hepatic I/R was induced in rats and mice by clamping the left branches of the portal vein and the hepatic artery. Cancer cells were injected intrasplenically. The number of metastatic nodules was counted on day 7 after I/R. TNF-α and E-selectin mRNA in hepatic tissue, serum fibrinogen degradation products and hepatic tissue levels of 6-keto-PGF1α, a stable metabolite of PGI2, were measured. RESULTS： AT inhibited increases in hepatic metastasis of tumor cells and hepatic tissue mRNA levels of TNF-α and E-selectin in animals subjected to hepatic I/R. Argatroban, a thrombin inhibitor, did not suppress any of these changes. Both AT and argatroban inhibited I/R-induced coagulation abnormalities. I/R-induced increases of hepatic tissue levels of 6-keto-PGF1α were significantly enhanced by AT. Pretreatment with indomethacin completely reversed the effects of AT. Administration of OP-2507, a stable PGI2 analog, showed effects similar to those of AT in this model. Hepatic metastasis in congenital AT-deficient mice subjected to hepatic I/R was significantly increased compared to that observed in wild-type mice. Administration of AT significantly reduced the number of hepatic metastases in congenital AT-deficient mice. CONCLUSION： AT might reduce I/R-induced hepatic metastasis of colon cancer cells by inhibiting TNF-α-induced expression of E-selectin through an increase in the endothelial production of PGI2. These findings also raise the possibility that AT might prevent hepatic metastasis of tumor cells if administered during the resection of liver tumors.

关键词： Antithrombin,reperfusion Metastasis factor-aE-selectin Hepatic ischemia/Prostacyclin Tumor necrosis factor-α

Effect of Nonequilibrium condensation of Moist Air on Transonic Flow Fields

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Journal of Thermal Science 2000年第1期9卷 37-44页

作者： Katsumi Shimamoto Shigeru matsuo Toshiaki Setoguchi Department of Mechanical Engineering Saga University l Honjo-machi Saga-shiSaga 840-8502 Japan

When condensation occurs in a supersonic flow field, the flow is affected by the latent heat released. In the present study, a condensing flow was produced by an expansion of moist air in nozzle with circular bump models and shock waves occurred in the supersonic parts of the flow fields. The experimental investigations were carried out to show the effects of initial conditions in the reservoir and nozzle geometries on the shock wave characteristics and the turbulences in the flow fields. Furthermore, in order to clarify the effect of condensation on the flow fields with shock waves, Navier-Stokes equations were solved numerically using a 3rd-order MUSCL type TVD finitedifference scheme with a second order fractional step for time integration. As a result the effect of condensation on the aspect of flow field has been clarified.

关键词： compressible flow condensation boundary layer control of shock wave moist air wavelet transform

Study for the Gas Flow through a Critical Nozzle

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Journal of Thermal Science 2003年第3期12卷 250-254,259页

作者： Jae-Hyung Kim Heuy-Dong Kim Shigeru matsuo Toshiaki Setoguchi School of Mechanical Engineering Andong National UniversityAndong 760-749 KoreaSchool of Mechanical Engineering Andong National UniversityAndong 760-749 KoreaDepartment of Mechanical Engineering Saga University1 Honjo Saga 840-8502 JapanDepartment of Mechanical Engineering Saga University1 Honjo Saga 840-8502 Japan

In the present study, computational work using the axisymmetric, compressible, Navier-Stokes equations is carried out to predict the discharge coefficient and critical pressure ratio of gas flow through a critical nozzle. The Reynolds number effects are investigated with several nozzles with different throat diameter. Diffuser angle is varied to investigate the effects on the discharge coefficient and critical pressure ratio. The computational results are compared with the previous experimental ones. It is known that the discharge coefficient and critical pressure ratio are given by functions of the Reynolds number and boundary layer integral properties. It is also found that diffuser angle affects the critical pressure ratio.

关键词： compressible flow choke boundary layer critical pressure ratio discharge coefficient