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Shigeru Matsuo

Bio: Shigeru Matsuo is an academic researcher from Saga University. The author has contributed to research in topics: Compressible flow & Nozzle. The author has an hindex of 12, co-authored 104 publications receiving 551 citations.


Papers
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TL;DR: In this paper, the authors investigated the influence of the nozzle geometry on the near-field structures of highly underexpanded SFA jets, and they showed that the distance from the nozzle exit to the Mach disk is an increasing function of the jet-pressure ratio.

52 citations

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TL;DR: In this article, 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) using a fully implicit finite volume scheme.
Abstract: 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

30 citations

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TL;DR: In this paper, a numerical investigation of transient flows in an axisymmetric over-expanded thrust-optimized contour nozzle is presented, where two types of flow separations such as free shock separation and restricted shock separation (RSS) shock structure occur.

29 citations

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TL;DR: In this article, the effect of nozzle geometries on the discharge coefficient was investigated using a 3rd order MUSCL finite volume method of ANSYS Fluent 13.0.

27 citations

Journal ArticleDOI
TL;DR: In this article, a variable ejector is used to obtain specific recirculation ratio under a given operating pressure ratio by varying the ejector throat area ratio, and numerical simulations are carried out to provide an understanding of the flow characteristics inside the Variable Ejector.
Abstract: The present study addresses a variable ejector which can improve the ejector efficiency and control the re-circulation ratio under a fixed operating pressure ratio. The variable ejector is a facility to obtain specific recirculation ratio under a given operating pressure ratio by varying the ejector throat area ratio. The numerical simulations are carried out to provide an understanding of the flow characteristics inside the variable ejector. The sonic and supersonic nozzles are adopted as primary driving nozzles in the ejector system, and a movable cone cylinder, inserted into a conventional ejector-diffuser system, is used to change the ejector throat area ratio. The numerical simulations are based on a fully implicit finite volume scheme of the compressible, Reynolds-Averaged Navier-Stokes equations. The results show that the variable ejector can control the recirculation ratio at a fixed operating pressure ratio.

25 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the authors present an exhaustive overview of the main experimental papers dealing with underexpanded jets, from those where there is clearly a lack of confidence, and some clues are given on the numerical methods that may be used if one wants to study such jets numerically, together with an emphasis on the specific thermodynamic difficulties associated to this kind of extreme conditions.

189 citations

01 Nov 1999
TL;DR: In this article, the stirring and mixing properties of one-phase coaxial jets, with large outer (annular) to inner velocity ratio ru = u2/u1 are investigated.
Abstract: The stirring and mixing properties of one-phase coaxial jets, with large outer (annular) to inner velocity ratio ru = u2/u1 are investigated. Mixing is contemplated according to its geometrical, statistical and spectral facets with particular attention paid to determining the relevant timescales of the evolution of, for example, the interface area generation between the streams, the emergence of its scale-dependent (fractal) properties and of the mixture composition after the mixing transition. The two key quantities are the vorticity thickness of the outer, fast stream velocity profile which determines the primary shear instability wavelength and the initial size of the lamellar structures peeled-off from the slow jet, and the elongation rate γ = (u2 − u1)/e constructed with the velocity difference between the streams and the gap thickness e of the annular jet. The kinetics of evolution of the interface corrugations, and the rate at which the mixture evolves from the initial segregation towards uniformity is prescribed by γ−1. The mixing time ts, that is the time needed to bring the initial scalar lamellae down to a transverse size where molecular diffusion becomes effective, and the corresponding dissipation scale s(ts) areformula herewhere Re and Sc denote the gap Reynolds number and the Schmidt number, respectively. The persistence of the large-scale straining motion is also apparent from the spectra of the scalar fluctuations which exhibit a k−1 shape on the inertial range of scales.

131 citations

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TL;DR: In this paper, a mathematical model of the compressible transonic single and two-phase flow of a real fluid is discussed, in which the specific enthalpy, instead of the temperature, is an independent variable.

111 citations

Journal ArticleDOI
TL;DR: In this article, the authors reviewed the research advances in condensation characteristics of the Laval nozzle and separation mechanism of the supersonic separator in detail from the perspectives of theoretical analysis, experiments and numerical simulation, and summarized the new application of this technology including natural gas liquefaction and removal of the acid gases.
Abstract: Supersonic separation technology is a new approach to condense and separate water, heavy hydrocarbons and other impurities from natural gas. This paper reviews the research advances in condensation characteristics of the Laval nozzle and separation mechanism of the supersonic separator in detail from the perspectives of theoretical analysis, experiments and numerical simulation, and summarizes the new application of this technology including natural gas liquefaction and removal of the acid gases. This review points out that while several aspects of this technology have been well studied, there still exist several issues in the practice. The further research topics are clarified to promote future applications such as the model modification of gas spontaneous nucleation rate to improve the prediction accuracy, and the combination the molecular dynamics technology with interface mechanics theory to study the collision and coalescence of the droplets and the interaction between gas and droplets under supersonic conditions.

98 citations

Journal ArticleDOI
TL;DR: In this paper, a numerical model is developed to investigate the fluid and dynamic characteristics of a direct-operated safety relieve valve (SRV) using the CFX expression language (CEL).

92 citations