• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.133-135
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• 2012

This study presents the prediction of NOx and mixing characteristics with several chemical reaction mechanisms of methane in EV burner of double cone. Experimental results are compared with numerical results for validation. Mixing characteristics are analyzed at monitoring points based on the modified unmixedness. The mixing characteristics were improved in a certain case, the lance injection case. In 1-step reaction case, inside of the cone, flame was formed and lots of NOx was generated because the fuel injected from the lance was overestimated. In 2-step reaction case, numerical results showed a good agreement with experimental results in a qualitative manner.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.97-98
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• 2010

This paper discusses shear behavior of Joint with premix mortar and strain hardening cement composites(SHCC) with PVA and PE fibers. The main variables considered include the type of cement composites(premixed mortar, SHCC with hybrid fiber) and reinforcement. It was evaluated that shear load had a good accordance with the test and equation result.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.323-327
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• 1996

Reinforced concrete(R/C) structures need repair and rehabilitation due to the deterioration such as a crack, spalling and disintergration. Numerous repair materials which are currently used in construction fields without any regulation are examined in terms of their serviceabilities and effectiveness. In this paper section of existing R/C beams are enlarged with repair materials, that is, epoxy, latex or premix. And then they are strengthened with rebar, steel poate of CFRP on the tension face. Structural behaviors of strengthened beams are investigated both statically and dynamically and they are compared with each. This paper summarizes the overall research plan.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.709-714
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• 1997

Recently, the repair materials for defected RC structures are being developed and the performance on repaired RC structures are being studied. This experiment is aimed to evaluate the flexural performance of the RC beams repaired by premix-type materials. The parameters used in this study is the repair materials, the repair length and the treatment of interface. Flexural capacity of repaired RC beams except the polymer-repaired RC beams are similar to that of the control beam. In the flexural capacity, the RC beams treated with chipping show better results than the RC beam without chipping. The various repair lengths of the repaired RC beam are not affected to the flexural capacity.

• Journal of Mechanical Science and Technology
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• v.18 no.1
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• pp.167-172
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• 2004

The present study has focused on numerical investigation on the flame structure, flame lift-off and stabilization in the partially premixed turbulent lifted jet flames. Since the lifted jet flames have the partially premixed nature in the flow region between nozzle exit and flame base, level set approach is applied to simulate the partially premixed turbulent lifted jet flames for various fuel jet velocities and co-flow velocities. The flame stabilization mechanism and the flame structure near flame base are presented in detail. The predicted lift-off heights are compared with the measured ones.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.6
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• pp.27-34
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• 2005

The purpose of this study is to improve the durability performance of polymer modified cement composites for repair of concrete under combined aging conditions. The experimental procedure was divided into three parts. First, the replacement level of mineral admixtures in polymer modified cement composites were determined in an experimental study based on a Box Behnken design. Second, the flow value, compressive strength and chloride permeability test of sixteen types of mixtures were conducted. Test results show that the polymer modified cement composites were effected on the improvement of the compressive strength and permeability performance. Third, the effects on the replacement level of silica fume mixture was evaluated by the compressive strength, chloride permeability, chemical resistance and repeated freezing and thawing cycles test. They demonstrated that the polymer modified cement composites using mixture of silica fume, fly ash, and blast furnace slag improved the durability performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.2-2
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• 1998

현대우주항공(주)가 미국의 AlliedSignal사와 함께 국제 공동 개발중인 10MW급의 ASE120 엔진은 항공용 엔진을 산업용으로 개조한 개조형 엔진으로서 희박 예혼합 예기화(Lean Premix prevaporization) 방식의 연소기를 쓰고 있다. 이 연소기는 연소에 관여하는 공기량을 부하에 따라 가감하여 일정 공연비를 유지하는 air staging법을 사용하고 있으며 이로써 연소화염온도를 일정치로 조절하여 연소중 생성되는 유해가스의 양을 목표치 이하로 제어한다. 연소화염온도 설계치는 2912$^{\circ}$F이며 배기가스 발생량은 NOx, CO모두 궁극적으로 10ppmv 이하를 목표로 하고 있다. 이러한 건식 저 배기가스(Dry Low Emission) 연소기가 그 역할을 다하기 위하여는 양호한 혼합기를 확보하는 것이 선결 문제이다. 본 연구소에서는 두 개의 혼합기(mixing can)가 180$^{\circ}$ 간격으로 환형 연소기(annular type)에 접선 방향으로 설치되어 대칭을 이루고 있고 혼합기의 혼합성능을 측정하기 위하여 제작된 시험장치에는 하나의 혼합기만을 쓰고 있다.

• Journal of the Korean Society of Combustion
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• v.17 no.4
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• pp.44-50
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• 2012

The present study was conducted to investigate the flame instability(evaluated by Markstein length and cellular instability) and laminar burning velocity in a constant volume combustion chamber at room temperature and elevated pressure up to 0.3 MPa to suggest the possibility of utilizing mixtures of syngas added DME-air premixed flames in internal combustion engines. The experimentally measured laminar burning velocities were compared to predictions calculated the PREMIX code with Zhao reaction mechanism. Discussions were made on effects of syngas addition into DME-Air premixed flames through evaluating laminar burning velocity, Markstein length, and cellular instability. Particular concerns are focused on cellular instability caused by hydrodynamic instability and diffusive-thermal instability.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.165-168
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• 2015

To measure laminar burning velocity in methane/air/ethylene mixture flame, propagating centrally ignited spherical premixed flame to radial direction was measured by high-speed schlieren images with elevated pressure. In this study, The experimentally measured unstretched laminar burning velocities of methane was compared with GRI mech 3.0 to validate experimental data and choose the radius range, respectively. numerical prediction using the PREMIX code with GRI mech 3.0, USC mech II,, and Wang mech were evaluated through comparison with experimental burning velocity with consideration of extrapolation on linear/nonlinear model.

• Journal of the Korean Society of Food Culture
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• v.20 no.3
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• pp.315-322
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• 2005

Kimchi noodle have a original taste and characteristics. This noodle was used for sour kimchi, kimchi taste powder, red bean fiber and emulsified oil etc. with RS(resistant starch) premix as blended wheat flour mixed to resistant starch. For manufacturing process of this kimchi mixed dry noodle, suitable kimchi of $pH3.70{\sim}3.80$ was required storage period during $4{\sim}5days$ at room temperature. At this point, the suitable treating amount of sour kimchi was about 20%(w/w) level. Manufacturing of kimchi noodle could be at the suitable manufacturing condition from use of kimchi taste powder and red bean fiber etc. Calori of this kimchi noodle was 308.17Kcal/100g as low level than wheat flour noodle as 355.82Kcal/100g, decreasing effect of calori was about 13.39%. This kimchi noodle had a characteristic sour and hot taste, that wasn't required the special seasoning and/or soup at this result.