• Title/Summary/Keyword: bowl diameter

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Effect of Reentrant Type Bowl Geometry on Combustion Characteristics in Diesel Engine -Effect of Aspect Ratio(Bowl Diameter/Bowl Depth)- (리엔트런트형 연소실 형상이 디젤기관의 연소특성에 미치는 영향 -연소실 형상비(Bowl직경/Bowl깊이)의 효과-)

  • Kwon, J.B.;Kim, H.S.;Kwon, I.K.;Oh, K.J.
    • Journal of ILASS-Korea
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    • v.1 no.4
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    • pp.54-62
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    • 1996
  • Effect of reentrant type bowl geometry on combustion characteristics was investigated in a D.1.diesel engine. The main factor was the aspect ratio (Bowl Diameter/Bowl Depth) of bowl of combustion chamber, and the measured data include the cylinder pressure, engine performance and emissions of the engine using the 4 kinds of the combustion chamber. Experimental results indicate that the effect of dc/H and nozzle protrusion are relatively small and there exists an optimum dc/H according to the combustion conditions. It is also found that the smoke emission is quite sensitive the overall combustion time where the 90 percentage of the combustion heat is released. The smoke mission increases by shortening the 90% combustion time while it decreases by delaying the 90% combustion time.

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Channel Design of Decanter-Type Centrifuge (II) - Particles' Sediment and the Bowl Length (원심분리기의 채널 설계(II) - 입자의 침강문제와 보울 길이)

  • 서용권
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.11
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    • pp.108-116
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    • 2003
  • In this paper, based on the concept of solid particles' sediment problem the working formula determining the bowl length of a Decanter-type centrifuge were derived. Assuming that particles are uniformly distributed along the vertical line of the liquid inlet position, it was possible to derive a constant value k used for determining the bowl length. It was shown from the sample calculations that the bowl length should be increased as the particle size to be removed from the liquid is decreased. The length also should be increased for the same particle size as the bowl diameter is decreased. To help the engineers choose a reasonable bowl diameter, the statistical relationship between the bowl diameter and the capacity of the international products is obtained and presented.

Effects of Aspect Ratio on Combustion Characteristics in Diesel Engine (연소실 형상비가 디젤기관의 연소특성에 미치는 영향)

  • Kwon, S.I.;Kwon, J.B.;Kim, H.S.
    • Journal of ILASS-Korea
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    • v.3 no.3
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    • pp.23-32
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    • 1998
  • The effect of reentrant type bowl geometry on combustion characteristics was investigated in a D.I. diesel engine. The main factor was the aspect ratio (Bowl Diameter / Bowl Depth) of bowl of combustion chamber, and the cylinder pressure, engine performance and emissions of the engine using the 4 kinds of the combustion chamber were meadured. Also, the combustion characteristics compared of the experimented and the calculated values which is used by the Hiroyasu's combustion model. The results are as follows; The effect of $d_c/H$ on ignition delay period are small. The smoke is corerelated to the heat release of the premixed and the diffusion combustion, i.g, the smoke decreased by decreasing the premixed combustion or increasing the diffusion combustion on cumulative heat release. The premixed combustion process has more effect than the diffusion combustion on smoke. The formal tendency of $d_c/H$ on engine performance has not appear.

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Channel Design of Decanter-Type Centrifuge (I) - Particles′ Suspension and the Channel Size (원심분리기의 채널 설계(I) - 입자의 부유문제와 채널 크기)

  • 서용권
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.10
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    • pp.148-155
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    • 2003
  • In this paper, based on the concept of solid particles' hovering problem the working formula for the channel design of a Decanter-type centrifuge were derived. The Shields' diagram and its curve-fitting formula were used in determining the criterion of particle size for the sediment. By using these formula the designer can determine the sectional configuration of the channel, such as the liquid depth, the normal pitch of the screw-blade arrangement and the bowl diameter.

An Optimization of the Combustion Parameters for Reducing Exhaust Emissions in a Direct Injection Diesel Engine (직접분사식 디젤기관 배기배출물 저감을 위한 연소인자의 최적화)

  • 주봉철;노병준;김규철;이삼구
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.78-85
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    • 2000
  • This study is to develop the diesel engine which has 6 cylinder natural aspiration direct injection type of 7.4$\ell$ with high performance, low emissions and low fuel consumption Finally the developed engine meets Korean `98 exhaust emission regulation for the city bus of heavy duty diesel engine by optimizing the various combustion parameters affecting performance and exhaust emissions. Combustion parameters are the swirl ratio of intake ports, the profile of injection pump`s cam affecting injection pressure, the design features of piston bowl of injection pump`s cam affecting injection pressure, the design features of piston bowl of combustion chamber and injector`s hole size. Through experimental analysis, various combustion parameters are optimized and the results are as follows; the swirl ratio is 2.20, the profile of injection pump`s cam is concave and re-entrant ratio, inner diameter of piston bowl and hole diameter of injector is 0.88,$\psi$64.0mm and $\psi$0.25mm respectively.

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Mobile Application based on Image Processing and a Proportion for Food Intake Measuring

  • Kim, Do-Hyeon;Kim, Yoon;Han, Yu-Ri
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.5
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    • pp.57-63
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    • 2017
  • In the paper, we propose a new reliable technique for measuring food intake based on image automatically without user intervention. First, food and bowl image before and after meal is obtained by user. The food and the bowl are divided into each region by the K-means clustering, Otsu algorithm, Morphology, etc. And the volume of food is measured by a proportional expression based on the information of the container such as it's entrance diameter, depth, and bottom diameter. Finally, our method calculates the volume of the consumed food by the difference between before and after meal. The proposed technique has higher accuracy than existing method for measuring food intake automatically. The experiment result shows that the average error rate is up to 7% for three types of containers. Computer simulation results indicate that the proposed algorithm is a convenient and accurate method of measuring the food intake.

A New Spray Chrysanthemum Cultivar, 'Snow Bowl', Resistant to White Rust, Long Vase Life and Single Type with White Petals for Cut Flower

  • Lim, Jin-Hee;Shin, Hak-Ki;Park, Sang Kun;Cho, Hae-Ryong;Rhee, Hye-Kyung;Kim, Mi-Seon;Joung, Hyang Young;Yae, Byeong Woo
    • FLOWER RESEARCH JOURNAL
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    • v.18 no.4
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    • pp.303-307
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    • 2010
  • A new spray chrysanthemum cultivar 'Snow Bowl' was released by National Institute of Horticultural & Herbal Science(NIHHS), Rural Development Administration (RDA), in 2008. The cross was made in 2005 between '03B1-230', breeding lines of NIHHS and 'Sei-Alps'. Trials were conducted from 2006 to 2008 for the evaluation and selection of this cultivar, including shading cultures in summer and retarding cultures in spring. The natural flowering time of 'Snow Bowl' is late October, but year-round flowering is possible by photo-periodic control. It has single type flowers with white petals. The growth of plant is very vigorous and it is resistant to white rust. The diameter of flower is 6.3cm. Number of flowers per stem and petals per flower are 12 and 31, respectively. Days to flowering under the short day treatment is about 59 and its vase life is 24.1 days in autumn season. 'Snow Bowl' was applied as No. 2009-179 on February 18, 2009 for variety protection and the plant variety protection rights have been registered as No. 3239 on August 3, 2010 at the Korea Seed and Variety Service.

Effects of Piston Shapes and Intake Flow on the Behavior of Fuel Mixtures in a GDI Engine

  • Kang, Jeong-Jung;Kim, Duck-Jool
    • Journal of Mechanical Science and Technology
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    • v.17 no.12
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    • pp.2027-2033
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    • 2003
  • The purpose of this study is to investigate the stratification of fuel vapor with different in-cylinder flow, piston cavity and injection timings in an optically accessible engine. Three different piston shapes that are F(Flat), B(Bowl) and R(Re-entrance) types were used. The images of liquid and vapor fuel were captured under the motoring condition using Laser Induced Exciplex Fluorescence technique. As a result, at early injection timing of 270 BTDC, liquid fuel was evaporated faster by tumble flow than swirl flow, where most of fuel vapor were transported by tumble flow to the lower region and both sides of cylinder for the F-type piston. At late injection timing of 90 BTDC, tumble flow appears to be moving the fuel vapor to the intake side of the cylinder, while swirl flow convects the fuel vapor to the exhaust side. The concentration of mixture in the center region was highest in the B-type piston, while fuel vapor was transported to the exhaust side by swirl flow in F and R-type pistons. At the injection timing of 60 BTDC, the R-type piston was better for stratification due to a relatively smaller bowl diameter than the others.

Combustion Optimization of Diesel 2.0 Liter Class Engine with 8-hole Injector Nozzle (8홀 노즐을 적용한 2리터 급 디젤 엔진 연소 최적화)

  • Kwon, Soon-Hyuk;Kim, Min-Su;Choi, Min-Seon;Cho, Sung-Hwan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.73-79
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    • 2008
  • Atomization speed of diesel fuel injected from 8-hole nozzle is faster than that of 7-hole nozzle because the hole diameter of 8-hole nozzle is smaller than that of 7-hole nozzle. But both insufficient distance between the fuel sprays and short penetration of injected sprays through 8-hole nozzle hole cause many harmful effects on combustion. In this study, we installed the 8-hole injectors to diesel 2.0 liter class engine, and optimized in-cylinder swirl and penetration via selecting and matching proper cylinder head and combustion bowl. Through this process, we found out the performance and emission potential of 8-hole nozzle installed engine are better than those of 7-hole nozzle installed one.

Manufacture for living supplies of Chestnut wood(Castanea crenata Sieb. et Zucc)

  • Kim, Sa-Ick;Lee, Seong-An;Kim, Dong-Kooi
    • Journal of the Korea Furniture Society
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    • v.20 no.6
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    • pp.575-580
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    • 2009
  • This study was carried out to manufacture wooden vessels by small diameter wood and wasted wood of Castanea crenata Sieb. et Zucc, which has been largely planted in southern area. We made spice set, tea box set, cookie vessel set, bowl set and accessory set. With the development of edged tools, the human species has been able to fashion wood to change and enhance its environment - one only has to look at the history of all cultures to see examples of wooden artifacts and structures. Even with the development of synthetic materials and the progress of automated, mechanized production of wood and wood products, the raw material is still processed by traditional methods to meet a never-ending demand for products made from this most desirable natural material. Chestnut wood has high added value and natural color grain and is very useful for wooden vessel. Thinned low grade trees can be used to produce wooden vessel. Therefore this result can promote thinning and produce good forestation.

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