• Title/Summary/Keyword: warm-up

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Automotive Engine Cooling Using a Phase Change Material (상변환 물질을 이용한 자동차 냉각 성능 향상에 대한 연구)

  • Kim, Ki Bum;Moon, Byung Heun;Choi, Kyung Wook;Lee, Ki Hyung
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.3
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    • pp.24-29
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    • 2013
  • An automotive cooling system is designed sufficiently large enough to endure the excessive heat load. In general driving condition, the cooling systems are too large to operate optimally. An experimental study was performed to evaluate a novel automotive cooling strategy using the latent heat of a phase change material (PCM). The strategy is expected to reduce the cooling system size up to around 35% and the engine warm-up time around 60%. The strategy will help improve fuel economy and emissions characteristics of vehicles as a result of reduced total body weight and shortened engine warm-up time by a smaller radiator, as well as more stable combustion mode due to constantly maintained coolant temperature.

The Origin, Changes and Compositive Principles of Baekhaoleejung-tang (백하오이중탕의 기원(基源), 변천(變遷), 구성(構成)에 대한 고찰(考察))

  • Shin, Hyun-Sang;Koh, Byung-Hee;Lee, Eui-Ju
    • Journal of Sasang Constitutional Medicine
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    • v.23 no.2
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    • pp.164-173
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    • 2011
  • 1. Objectives: The purpose of this study is to understand the origin, the progressive changes and the constructive principles of Packhaoleejung-tang (白何烏理中湯) 2. Methods: Packhaoleejung-tang and other related prescriptions were analyzed in terms of their pathological indications, based on "Donguisusebowon Chobongwon (東醫壽世保元 草本卷)", "Donguisusebowon Gabobon (東醫壽世保元 甲午本)", "Donguisusebowon Sinchukbon (東醫壽世保元 辛丑本)", "Dongmuyugo (東武遺稿)", "Shanghanlun (傷寒論)". 3. Results and Conclusions: (1) The origin of Packhaoleejung-tang is leejung-tang from "Shanghanlun (傷寒論)". Packhaoleejung-tang inherited some of the principles from "Shanghanlun (傷寒論)" Insamkeiji-tang (2) "Gabobon(甲午本)"'s one prescription Hyangsaleejung-tang emphasizes the effect of lossen up by using Pogostemonis Herb (藿香),Amomi Fructus(砂仁). "Gabobon(甲午本)"'s another prescription Packhaoleejungtang emphasizes the effect of warm up stomach by using Cinnamomum cassia Blume (桂枝), Allium sativum Linne (獨頭蒜), Cynanchum wilfordii(白何首烏). "Sinchukbon(辛丑本)"'s prescription Packhaobujaleejungtang emphasizes the effect of warm up stomach by using Aconitum carmichaeli(附子) (3) The Packhaoleejung-tang is composed of 7 herbs. Atractlodis Rhizoma White(白朮), Glycyrrhizae Radix(甘草), Paeoniae Radix Alba(白芍藥) support Soeumin's spleen root (脾元), and Zingiberis Rhizoma(乾薑),Cinnamomum cassia Blume (桂枝, Cynanchum wilfordii(白何首烏) warm up stomach. Citri Pericarpium(陳皮) circulate Qi and encourage the descension of Yin.

Deformation Behavior during Warm Rolling in AA3103 Sheet deformed by CCSS (CCSS 가공한 AA3103 판재에서 온간 압연 소성 거동)

  • Lee J. P.;Kang H. K.;Huh M. Y.;Park J. W.;Chung Y. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.10a
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    • pp.215-217
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    • 2004
  • In order to obtain the initial starting sample having a random texture and fine grains, aluminum alloy 3103 sheets were repeatedly deformed by CCSS up to six passages and subsequently annealed at $300^{\circ}C$ for 1h. These samples were cold rolled at room temperature and also warm rolled at $250^{\circ}C$. Changes in rolling temperature gave rise to the different texture evolution. Warm rolling led to the pronounced texture gradients comprising the shear texture at the surface and the rolling texture at the sheet center. The formation of the rolling texture components, i.e., the ${\beta}$-fiber, was promoted by cold rolling than warm rolling.

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Self-excited Variability of the East Korea Warm Current: A Quasi-Geostyophic Model Study

  • Lee, Sang-Ki
    • Journal of the korean society of oceanography
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    • v.34 no.1
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    • pp.1-21
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    • 1999
  • A two-layer quasi-geostrophic numerical model is used to investigate the temporal variability of the East Korea Warm Current (EKWC), especially the separation from the Korean coast and the generation of warm eddies. An attention is given on the active role of the nonlinear boundary layer process. For this, an idealized flat bottom model of the East Sea is forced with the annual mean wind curl and with the inflow-outflow specified at the Korea (Tsushima) and Tsugaru Straits. Two types of separation mechanisms are identified. The first one is influenced by the westward movement of the recirculating leg of the EKWC (externally driven separation),the second one is solely driven by the boundary layer dynamics (internally driven separation). However, these two processes are not independent, and usually coexist. It is hypothesized that 'internally driven separation' arises as the result of relative vorticity production at the wall, its subsequent advection via the EKWC, and its accumulation up to a critical level characterized by the separation of the boundary flow from the coast. It is found that the sharp southeastern corner of the Korean peninsula provides a favorable condition for the accumulation of relative vorticity. The separation of the EKWC usually accompanies the generation of a warm eddy with a diameter of about 120 km. The warm eddy has a typical layer-averaged velocity of 0.3 m/s and its lifespan is up to a year. In general, the characteristics of the simulated warm eddy are compatible with observations. A conclusion is therefore drawn that the variability of the EKWC is at least partially self-excited, not being influenced by any sources of perturbation in the forcing field, and that the likely source of the variability is the barotropic instability although the extent of contribution from the baroclinic instability remains unknown. The effects of the seasonal wind curl and inflow-outflow strength are also investigated.

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Clothing Temperature Changes of Phase Change Material-Treated Warm-up in Cold and Warm Environments

  • Choi Kyeyoun;Chung Hyejin;Lee Boram;Chung Kyunghee;Cho Gilsoo;Park Mikyung;Kim Yonkyu;Watanuki Shigeki
    • Fibers and Polymers
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    • v.6 no.4
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    • pp.343-347
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    • 2005
  • The purpose of this study was to investigate the appropriate amounts of phase change materials to give objective and subjective wear sensations. Vapor-permeable water-repellent fabrics with (WR-PCM) and without (WR) octadecane containing microcapsules were obtained by wet-porous coating process. Then, calculating the area of the WR-PCM treated clothes, we estimated the total calories of the clothing by multiplying the heat of fusion and heat of crystallization of PCM to the calculated area. Wear tests were conducted in both warm environment $(30^{\circ}C,\;65\%\;RH)$ and cold environment $(5^{\circ}C,\;65\%\;RH)$ with sports warm up style experimental garments made with WR and WR-PCM fabrics. Rectal, skin, and clothing microclimate temperatures, saliva and subjective evaluation measurements were done during the wear test. There was no difference of rectal and mean skin temperatures between WR and WR-PCM, but the clothing microclimate temperature of WR-PCM under warm environment was slightly lower than that of WR. In cold environment, WR-PCM showed much higher temperature than in WR. Saliva change did not appear between clothes, but did between two environments. Although subjective sensation between WR and WR-PCM was not significantly different, WR-PCM was rated as cooler than WR in warm environment and as warmer than WR in cold environment. The results of this study indicated that octadecane containing microcapsules in water-repellent fabric provide cooling effect.

A Study on Latent-gi by Yexiangyan "Wenrejingwei" ("온열경위(溫熱經緯)" 중(中) 섭향암(葉香巖)의 삼시복기외감(三時伏氣外感)에 관한 연구(硏究))

  • Ahn, Joon-Mo;Song, Ji-Chung;Jeong, Hyun-Jong;Keum, Kyung-Soo
    • Journal of the Korean Institute of Oriental Medical Informatics
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    • v.16 no.2
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    • pp.163-187
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    • 2010
  • The concept of latent-gi(伏氣) was first mentioned in Yellow Emperor's Canon of Internal Medicine. For example, Elementary Questions states, "Damage by cold in winter necessarily engenders warm disease in the spring." Zhang Zhong-Jing of Han Dynasty in On Cold Damage and Miscellaneous Diseases mentions warm disease, stating, for example, "Greater yang disease with heat effusion and cough and without aversion to cold is warm disease. If sweating is applied, and there is generalized heat, this is wind warmth." However, the concept of warm disease was not central to his systematic presentation of externally contracted disease which placed the emphasis on wind and cold as the major causes of these diseases. Zhang Zhong-Jing's theories centuries after in the Sung Dynasty were to become the focus of the cold damage school, whereas the concept of warm disease was to become the focus of a rival school, the warm disease school. In the Sui-Tang Period, The Origin and Indications of Disease mentions warm diseases, their causes, patterns, and major principles of treatment. Successive generations of doctors wrote about warm disease, and in the Ming Dynasty writings on the subject become more prolific. This development is attributable on the one hand to the opening up of the south of China where febrile diseases tended to be of a different nature than in the north, and on the other to pestilences arising as a result of wars. In this period, Wu You-Xing in On Warm Epidemics explained in detail the laws governing the origin, development and pattern identification of warm epidemics. Notably, he posed the etiological notion of a contagious perverse gi.

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OXIDATION CHARACTERISTICS OF PARTICULATE MATTER ON DIESEL WARM-UP CATALYTIC CONVERTER

  • Choi, B.C.;Yoon, Y.B.;Kang, H.Y.;Lim, M.T.
    • International Journal of Automotive Technology
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    • v.7 no.5
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    • pp.527-534
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    • 2006
  • Modern passenger cars with diesel engines are equipped with DOC(diesel oxidation catalyst) for the purpose of reducing HC and CO in the exhaust stream. Cold start exhaust emissions pose troubles here as on gasoline engine vehicles. As a result, some of the diesel passenger cars roll off todays the assembly lines with WCC(warm-up catalytic converter). Oxidation characteristics of the particulates in WCC is analyzed in this study by EEPS(engine exhaust particulate size spectrometer). The maximum number of PM is found to come out of WCC in sizes near 10nm when an HSDI diesel engine is operated under the conditions of high speed and medium to heavy load. When the temperature of the WCC exceeds $300^{\circ}C$, the number of PM smaller than 30 nm in diameter sharply increases upon passing through the WCC. Total mass of emitted PM gets reduced downstream of the WCC under low speed and light load conditions due to adsorption of PM onto the catalyst. Under conditions of high speed and medium to heavy load, the relatively large PM shrink or break into fine particles during oxidation process within the WCC, which results in more mass fraction of fine particles downstream of the WCC.

Sizing of Powertrain in Fuel Cell Hybrid Vehicles (연료전지 하이브리드 자동차의 동력전달계의 용량 선정)

  • Zheng, Chun-Hua;Shin, Chang-Woo;Park, Yeong-Il;Cha, Suk-Won
    • Transactions of the Korean Society of Automotive Engineers
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    • v.19 no.6
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    • pp.113-118
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    • 2011
  • Fuel Cell Hybrid Vehicle (FCHV) is one of the most promising candidates for the next generation of transportation. It has many outstanding advantages such as higher energy efficiency and much lower emissions than internal combustion engine vehicles. It also has the ability of recovering braking energy. In order to design an FCHV drive train, we need to determine the size of the electric motor, the Fuel Cell System (FCS), and the battery. In this paper, the methodology for the sizing of these components is introduced based on the driveability constraints of the FCHV. A power management strategy is also presented because the battery energy capacity depends on it. The warm-up time of the FCS is also considered in the power management strategy and the simulation result is compared to that without considering the warm-up time.

Numerical Analysis of Effective Turbocharger and Baffle on Flow Field in Warm-up Catalyst for Diesel Vehicles (디젤자동차용 웜업촉매 내의 유동장에 미치는 터보차저 및 배플의 영향에 관한 수치해석)

  • Choi, Byung-Chul;Juhng, Woo-Nam;Kang, Chang-Hyuk;Wi, Dae-Woong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.5
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    • pp.29-36
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    • 2008
  • Diesel vehicle is growing in importance in light-duty sector as a way of reducing greenhouse gases due to improved fuel economy. Carbon monoxide, gas-phase hydrocarbon and organic fraction of diesel particulates can be oxidized to harmless products using a diesel warm-up catalyst (WCC). This study investigated the effect of a turbocharger and a baffle on flow fields and temperature distributions in the WCC for Diesel vehicles by a numerical analysis. In the case of the WCC with the turbocharger, velocity vectors and temperatures of inlet of the WCC have the relatively homogeneous distributions by the swirl generated from the turbocharger. Velocity vectors and temperatures of inlet of the WCC with the turbocharger and the baffle have the improved distributions in homogeneity compared with the case of the WCC without the baffle. The homogeneous flow field and the temperature distribution in the WCC may contribute to improve the conversion performance of the catalysts.

Effects of High Frequency Warm Needling of LI4 Acupoint on the Carrageenan-induced Arthritis in Rats (합곡(合谷)(LI4)의 고주파 온침 자극이 흰쥐의 족과(足踝) 관절염(關節炎)에 미치는 효과)

  • Park, Sang-Yeon;Kwon, Oh-Sang;Choi, Won-Jong;Kim, Jae-Hyo;Kim, Kyung-Sik;Sohn, In-Chul;Ahn, Seong-Hun
    • Korean Journal of Acupuncture
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    • v.26 no.2
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    • pp.61-74
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    • 2009
  • Objectives: The warm needling technique is a method which combines the effects of acupuncture with those of moxibustion. The purpose of this study was to find the stimulus effects of a high frequency warm needling device when stimulating acupoint $LI_4$ on the carrageenan-induced arthritis. Methods: This study was to observe the effects to edema reaction, WBF(weight bearing force), NO concentration, nNOS expression after the electro high frequency stimulus of high frequency warm needling device on LI4 with insulated acupuncture needle. Results: The effect of the high frequency warm needling device is to rise up the temperature in proportion to the current intensity. After stimulating on the acupoint $LI_4$ of the carrageenan-induced arthritis in rats with the high frequency warm needling device, it significantly reduced edema in the rat's foot. In addition, WBF, NO concentration of spinal cord (nmol/mg), and nNOS relative expression were reduced. Conclusions: The above results support the idea that stimulus by the high frequency warm needling device on $LI_4$ produces a potent analgesic effect in the arthritis pain model of the rat. Moreover, stimulus by the high frequency warm needling device modulates endogenous NO through the suppression of nNOS protein expression.

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