• 한국분무공학회지
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• 제9권3호
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• pp.42-49
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• 2004

The present article investigates the influence of droplet drag models on predictions of diesel spray behaviors under ultra-high injection pressure conditions. To consider drop deformation and shock disturbance, this study introduces a new hybrid model in predicting drag coefficient from the literature findings. Numerical simulations are first conducted on transient behaviors of single droplet to compare the hybrid model with earlier conventional model. Moreover, using two different models, extensive numerical calculations are made for diesel sprays under ultra-high pressure sprays. It is found that the droplet drag models play an important role in determining the transient behaviors of sprays such as spray tip velocity and penetration lengths. Numerical results indicate that this new hybrid model yields the much better conformity with measurements especially under the ultra-high injection pressure conditions.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.71-74
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• 2008

NUFLEX is a general purpose thermo/fluid flow analysis program which has various physical models including spray. In NUFLEX, spray models are composed of breakup and collision models of droplet. However, in case of diesel engine, interaction between wall-film and impingement model considering heat transfer is not coded in NUFLEX. In this study, Lee & Ryou impingement & wall-film model considering heat transfer is applied to NUFLEX. For the verification of this NUFLEX program, numerical results are compared with experimental data. Differences of film thickness and radius between numerical results and experimental data are within 10% error range. The results show that NUFLEX can be used for comprehensive analysis of spray phenomena.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 춘계 학술대회논문집
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• pp.99-102
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• 2007

NUFLEX is a general purpose program for the analysis 3D thermo/fluid flow and pre/post processor in a complex geometry. NUFLEX is composed various physical models, such as phase change(solidification/melting) and spray, MHD(Magneto Hydraulic Dynamics) models. It is possible to simulate of continuous cast iron process and spray droplet breakup/collision phenomenon. For the verification of these models, compared with the experimental data and commercial CFD code's results. The results show good agreements with experimental and comercial CFD codes's results.

• 한국분무공학회지
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• 제5권2호
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• pp.6-11
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• 2000

• 시멘트 심포지엄
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• 통권40호
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• pp.181-185
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• 2013

• 농약과학회지
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• 제4권4호
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• pp.87-92
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• 2000

인축독성 및 잔효성이 낮은 환경친화적인 Petroleum spray oil(PSO; DC-Tron $Plus^{(R)}$)의 살포에 따른 귤응애에 대한 방제효과 및 약해발생에 관하여 포장조건하에서 검토하였다. PSO를 0.25%, 0.33%, 0.5% 및 1%를 처리한 결과, 귤응애에 대한 방제효과는 모든 농도에서 대조약제(tebufenpyrad, bifenazate, sun spray oil)와 비교하여 비슷하거나 뛰어났으며, 약효도 40일 이상 장기간 지속되는 경향을 나타냈다. 그런데 PSO 0.5% 이상 처리시에는 감귤잎에 유침상 증상이 일부 나타났으나 2개월후에 거의 사라졌으며, 낙엽율과 낙과율은 다소 증가하는 경향이었다. 그리고 PSO 1%를 감출 더뎅이병 및 검은점무늬병의 적용약제와 각각 혼용처리한 결과, 더뎅이병 방제약제인 Fluazinam 수화제와 혼용한 경우 일부 신초가 타거나 일부 신엽에 흑점이 발생하였다. 이러한 약효와 약해 결과를 고려해 볼 때 귤응애 방제를 위한 하절기 PSO 적정 살포농도는 0.25% 또는 0.33% 정도일 것으로 판단된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.37-40
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• 2009

본 연구에서는 케로신/과산화수소 점화용 분사기의 설계/제작하여 분무특성에 관한 연구를 수행하고자 하였으며, 이에 앞서 촉매점화방식으로 적용할 때 가장 적합한 분사기를 설계하고자 하였다. 설계/제작된 분사기를 수류시험을 통해 질량 유량 및 분산각을 측정하였다. 그 결과 케로신의 목표 질량유량(12.88 g/s)은 설계 차압과 같은 차압인 3 bar에서 측정되었으며, 이 때 분산각은 $40^{\circ}$을 확인하였다. 또한 과산화수소의 목표 질량 유량(94.39 g/s)은 설계 차압(3 bar) 보다 작은 1 bar에서 측정됨을 확인하였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.33-39
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• 2009

Asphalt waterproofing method has a long history over 80years since introduce to domestic market. This method has a good point as high water proofing not permeable to water by material performance of bitumen, In spite of high waterproofing, the application has become decreased. This asphalt method has some problem such as work safety, low workability by complicated work process, environmental problem in job site, it should be solve by complementary measures. 'Therefore, in this paper, suggest the principle of high pressure spray by heat cycle type equipment by analysis of exist problem and materials investigation. And. study and examine the spray type degeneration rubberized asphalt membrane materials to adopt job site. Moreover, suggest the evidence by inspection about waterproofing performance by Korean Industrial Standard through the performance test of the spray type degeneration rubberized asphalt membrane materials.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
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• pp.20-23
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• 2011

가스메탄과 액체산소를 추진제로 사용하는 스월 동축형 인젝터에서 리세스 길이 변화에 따른 분무특성 및 미립화 특성에 대한 연구를 수행하였다. 패터네이터를 이용하여 분산각 및 분무의 질량분포를 측정하였으며, 미립화 특성을 살펴보기 위해 GSV(Global Size and Velocity)를 이용하여 평균액적크기를 측정하였다. 결과적으로 액체만 분사한 경우 리세스 길이가 증가함에 따라 분산각은 감소하나 미립화 특성이 좋아지는 것을 확인하였고, 기체/액체를 동시 분사한 경우 액체만 분사한 경우에 비해 분산각은 작아지나 미립화 특성이 좋아지는 것을 확인하였다.

• 대한조선학회논문집
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• 제59권2호
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• pp.80-88
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• 2022

A systematic experimental study is carried out for the fire fighting monitor nozzle of 65A diameter to design and manufacture a new nozzle with better water spray performance than available domestic nozzles. The nozzle inlet pressure, flow rate and reach for the discharged water from the nozzle are measured by utilizing the experimental facility consisting of two pumps and piping system with a flow meter and pressure gauges. It was found that the baffle position and baffle head chamfering were the most sensitive design factors to be remarkably changed in the flow rate of the discharged water. Also, It was confirmed that the baffle position and the water exit area had the significant effect on the change in reach distance. The results obtained from this study are expected to be used effectively to design new nozzles with excellent spray performances and also to validate numerical analysis results for evaluating the water spray performance of fire fighting monitor nozzles.