• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.5
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• pp.569-579
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• 2004

The lift-off characteristics of lifted laminar propane jet flames highly diluted with nitrogen are investigated introducing acoustic forcing with a fuel tube resonance frequency. A flame stability curve is obtained according to forcing strength and the nozzle exit velocity for N2 diluted flames. Flame lift-off behavior is globally classified into three regimes; 1) a weakly varying partially premixed behavior caused by a collapsible mixing for large forcing strength, 2) a coexistent behavior of the edge flame and a weakly varying partially premixed behavior for moderate forcing strength, and 3) edge flame or triple flame behavior for small forcing. It is shown that the laminar lifted flame with forcing affects flame lift-off behavior considerably, and is also clarified that the flame characteristic of flame base is well described with the penetration depth of the degree of mixing, ${\gamma}$$\_$$\delta$/. It is also confirmed that the weakly varying partially premixed flame caused by a collapsible mixing fur large forcing strength behaves as that just near flame blow-out in turbulent lift-off flame.

• 한국연소학회:학술대회논문집
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• 2003.05a
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• pp.65-73
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• 2003

An experimental study on flame lift-off characteristics of propane jet flame highly diluted with nitrogen has been conducted introducing acoustic forcing with a tube resonant frequency. A flame stability curve is attained according to forcing strength and nozzle exit velocity for $N_2$ diluted flames. Flame lift-off behavior with forcing strength and nozzle exit velocity is globally categorized into three; a well premixed behavior caused by a collapsible mixing for large forcing strength, a coexistent behavior of well-premixed and edge flames interacting with well-organized inner fuel vortices for moderate forcing strengths, and edge flame behavior for small forcing strengths. Special focus is concentrated on the coexistent behavior of the flame base in lifted flame since this may give a hint to a possibility which the flame base behaves like a well-mixed premixed flame in highly turbulent lifted flames. It is also shown that the acoustic forcing to self-pulsating laminar lifted flame affects flame lift-off behavior considerably which is closely related to downstream flow velocity, mixture strength, effective fuel Lewis number, and flame stretch.

• Journal of Navigation and Port Research
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• v.42 no.5
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• pp.331-340
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• 2018

Shipping containers promote rapid development of the transport industry, and generate economic and social value. However, problems often occur due to imbalance in dynamics between exports and imports, container relocation, traffic congestion, and general shipping network designs. So, efficient and cost-effective cargo management has become crucial for the Jeju Island - Mokpo container route (JMCR) in South Korea. Dozens of recent studies reveal that collapsible or foldable containers, may become an innovative solution to problematic issues within the shipping industry. The major purpose of this study is to discuss conditions required for successful commercial application of foldable containers, based on a cost-benefit analysis precisely for the JMCR. Findings reveal usage of foldable containers can be cost-effective, if containers make a "FULL<->EMPTY" route. To the contrary, a "FULL<->FULL" route can drastically increase expenditure. However, economic analysis of actual figures for 2010-2015 indicate that benefits for Mokpo - Jeju direction are significant to cover losses on the Jeju - Mokpo line. Seasonal patterns and mixing percentages of foldable and standard containers on the route, may also produce cost-effective solutions. Sensitivity analysis reveals that benefits from using foldable containers, depend mostly on empty container shares in addition to various extra costs.