Unsteady Three-Dimensional Computations of the Penetration Length and Mixing Process of Various Single High-Speed Gas Jets for Engines

Konagaya, Remi; Naitoh, Ken; Tsuru, Kohta; Takagi, Yasuo; Mihara, Yuki

doi:10.4271/2017-01-0817

Cited by 6 publications

(2 citation statements)

References 21 publications

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“…Moreover, on the penetration length, computation results with the nonlinear correction method is similar to computation results without corrections, which agrees with experiment results on the penetration length of the hydrogen jet [20].…”

Section: Application To a Three-dimensional Jet Flow Injected Into A supporting

confidence: 86%

Deterministic and stochastic computations of mysterious internal flows: based on a nonlinear local correction method with global conservativity

Konagaya

Naitoh

Kijima

2020

JASSE

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The present paper shows a new approach for solving two types of fluid problems, which has recently emerged and has been an unsolved mysteriously for over 100 years. The first problem emerged recently is a very small amount of numerical errors comparable to pollutant emissions such as unburned hydrocarbon fuel (HC) and NOx at order of ppm or less. A new nonlinear numerical method of global and local corrections for the deterministic compressible Navier-Stokes equation for multi-components of gases is proposed and tested to overcome this first problem, while accurately evaluating fluid-dynamic instability related to turbulence and thermal efficiency as result of spatially-integrated thermodynamic quantities, related to total amount of CO2 exhausted, in power systems including combustion engines. It is stressed that the present nonlinear correction method applied for the stochastic Navier-Stokes equation is also effective for the second mysterious problem which has been unsolved for over 100 years, which is the spatial transition point from laminar to turbulent flows in pipes.

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Section: Application To a Three-dimensional Jet Flow Injected Into A supporting

confidence: 86%

Deterministic and stochastic computations of mysterious internal flows: based on a nonlinear local correction method with global conservativity

Konagaya

Naitoh

Kijima

2020

JASSE

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“…Another evidence is in our previous report, in which asymmetric flow pattern in single high-speed gas jet having turbulent vortices and wrinkle of contact surface between gas jet and ambient air is computed by the present numerical method based on the CIP and CUP method. (Konagaya et al 2017) This instability on single jet computed may also imply the efficiency of our numerical model. Figure 19 also includes the results of computations without the turbulence model, shown in Fig.…”

Section: Position Of Shock Frontsmentioning

confidence: 78%

Unsteady three-dimensional computations and experiments of compression flow formed by collision of supermulti-jets

Tsuru

Konagaya

Kawaguchi

et al. 2018

JTST

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The single-point compression principle, based on the collision of pulsed supermulti-jets, which is proposed in our previous reports, has the potential of obtaining both a high compression ratio and relatively low combustion noise, leading to a lower exhaust gas temperature, i.e., high thermal efficiency for the next generation of engines. The supermulti-jets also enclose high-temperature combustion gas around the chamber center, which means less heat loss to the chamber wall, i.e., higher thermal efficiency due to the air-insulation effect. Here, experimental and computational visualizations around the compression point should be examined in order to confirm the occurrence of single-point compression. Thus, in the present paper, we present experimental Schlieren photographs of flows formed by the collision of supermulti-jets without combustion and the results of unsteady three-dimensional computations conducted with the compressible Navier-Stokes equations, while the Cubic Interpolated pseudo-Particle (CIP) and Combined Unified Procedure (CUP) method is employed as numerical algorithm. Comparison of the experimental and computational results show fairly good agreement in time and space. Schlieren photographs and computational visualizations obtained for various conditions of four-, eight-, and sixteen-nozzles of jets are axial symmetrical, which will indicate the single-point compression based on the collision of supermulti-jets. Computations for asymmetrical distribution of seven nozzles also bring results showing nearly symmetric flow.

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Progress of Performance, Emission, and Technical Measures of Hydrogen Fuel Internal-Combustion Engines

Gao

et al. 2022

Energies

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To achieve the goals of low carbon emission and carbon neutrality, some urgent challenges include the development and utilization of low-carbon or zero-carbon internal combustion engine fuels. Hydrogen, as a clean, efficient, and sustainable fuel, has the potential to meet the abovementioned challenges. Thereby, hydrogen internal combustion engines have been attracting attention because of their zero carbon emissions, high thermal efficiency, high reliability, and low cost. In this paper, the opportunities and challenges faced by hydrogen internal-combustion engines were analyzed. The progress of hydrogen internal-combustion engines on the mixture formation, combustion mode, emission reduction, knock formation mechanism, and knock suppression measures were summarized. Moreover, possible technical measures for hydrogen internal-combustion engines to achieve higher efficiency and lower emissions were suggested.

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Unsteady Three-Dimensional Computations of the Penetration Length and Mixing Process of Various Single High-Speed Gas Jets for Engines

Cited by 6 publications

References 21 publications

Deterministic and stochastic computations of mysterious internal flows: based on a nonlinear local correction method with global conservativity

Deterministic and stochastic computations of mysterious internal flows: based on a nonlinear local correction method with global conservativity

Unsteady three-dimensional computations and experiments of compression flow formed by collision of supermulti-jets

Progress of Performance, Emission, and Technical Measures of Hydrogen Fuel Internal-Combustion Engines

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