• Title/Summary/Keyword: RIM

Search Result 6,321, Processing Time 0.039 seconds

Numerical Study of Film Cooling Characteristics in Turbine Blade Cavity (터빈 블레이드 캐버티 내 막냉각 특성에 관한 수치해석적 연구)

  • Kim, Kyung-Seok;Cho, Hyung-Hee;Kang, Shin-Hyoung
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03b
    • /
    • pp.648-651
    • /
    • 2008
  • Numerical calculations are performed to simulate the film cooling effect of turbine blade tip with squealer rim. Because of high temperature of inside rim, squealer rim is damaged easily. Therefore many various cooling systems were used. The calculations are based on 100,000 Reynolds number in linear cascade model. A blade has 2% tip clearance and 8.4% rim height. The axial chord length and turning angle is 237mm, 126$^{\circ}$. Numerical calculations are performed without and with film cooling. In a film cooling in the cavity, hot spots of cavity were cooled effectively. However hot spots of suction side rim still remains. The CFD results show that the circulation flow in cavity of squealer tip affects the temperature rise of squealer rim. To maintain the blade integrity and avoid the excessive hot spot of blade, rearrangement of cooling hole is needed.

  • PDF

Formation of a Core/Rim Structure in Ti(C, N)-based Cermets (Ti(C, N)계 써메트의 유심구조 형성거동)

  • Kim, Suk-Hwan
    • Journal of Powder Materials
    • /
    • v.13 no.1 s.54
    • /
    • pp.10-17
    • /
    • 2006
  • Model experiment was introduced to obtain the formation of a core/rim structure by only liquid phase reaction in Ti(C, N)-based cermet alloys. Infiltrated Ti(C, N)-Ni, $MO_2C-Ni$, and TaC-Ni cermets were bonded to sandwiched specimen by heat treatment $1450^{\circ}C$ for 5hr. With nitrogen addition, both (Ti, Mo) (C, N) and (Ti, Ta) (C, N) rim structure was nucleated around comer of cuboidal Ti(C, N) core. However, equilibrium shapes of(Ti, Mo) (C, N) and (Ti, Ta) (C, N) rim were different possibly due to the effect of interface energy. The core/rim and rim! binder interfaces were parallel to each other with TaC addition, while rotated to each other with $MO_2C$ addition.

SCHENSTED INSERTION AND DELETION ALGORITHMS FOR SHIFTED RIM HOOK TABLEAUX

  • Lee, Jaejin
    • Korean Journal of Mathematics
    • /
    • v.14 no.1
    • /
    • pp.125-136
    • /
    • 2006
  • Using the Bumping algorithm for the shifted rim hook tableaux described in [5], we construct Schensted insertion and deletion algorithms for shifted rim hook tableaux. This may give us the combinatorial proof for the orthogonality of the second kind of the spin characters of $S_n$.

  • PDF

Rim Sign in Aucte Cholecystitis (급성 담낭염 진단시 Rim Sign의 의의)

  • Koh, Eun-Mi;Lee, Kyung-Han;Yang, Seoung-Oh;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
    • /
    • v.23 no.1
    • /
    • pp.35-39
    • /
    • 1989
  • The "rim sign" is a rim of increased hepatic activity adjacent to the gall bladder fossa and known as an useful indicator of acute cholecystitis. Also, many reports suggested that if rim sign is positive there is an increased risk for complications such as perforation and gangrene. To evaluate the usefulness of this rim sign, we reviewed 32 cases that were pathologically confirmed. The incidence of rim sign was 47% similar to other reports but with our results, the rim sign was not specific to acute cholecystitis nor indicator of increased risk for complications.

  • PDF

A Case of Solitary Metastatic Deposit in the Orbital Rim from Follicular Thyroid Cancer (단일성 안와 골병변으로 확인된 갑상선 여포암의 원격 전이 1예)

  • Jeon, Gyeong Hwa;Oh, Hyeon Seok;Choi, In Ho;Byeon, Hyung Kwon
    • Korean Journal of Head & Neck Oncology
    • /
    • v.37 no.2
    • /
    • pp.105-109
    • /
    • 2021
  • Follicular thyroid carcinoma (FTC) is the second most common thyroid cancer, following papillary carcinoma. Metastasis to the orbital rim from FTC is very rare. We recently experienced a case of FTC with metastasis to the orbital rim in a 74-year-old woman, who initially presented with a huge thyroid mass and an asymptomatic solitary orbital rim lesion. The solitary orbital rim lesion was suspected to be a separate disease entity such as lymphoma from the preoperative imaging, but bone metastasis from FTC was finally confirmed after orbital rim resection and total thyroidectomy. During follow-up, the patient presented multiple bone metastasis, so the solitary orbital rim lesion was considered a clinical sign of systemic metastasis from FTC. Therefore, we present this unique case with a review of the literature.

Estimating Unsteady Soil Loss due to Rainfall Impact according to Rim Fire at California

  • Choi, Hyun;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.35 no.4
    • /
    • pp.269-280
    • /
    • 2017
  • Recently, in the United States, there has been short-term intensive rainfall due to El Ni?o and Rania. The Rim Fire was a wildland fire that was started in a remote canyon in Stanislaus National Forest in California. This portion of the central Sierra Nevada spans Tuolumne and Mariposa counties. This study is about estimating unsteady soil loss due to rainfall impact according to Rim Fire at California. It implies that caution needs to be taken in selecting the grid size for estimating soil loss using numerical modeling approach. Soil loss increased in all duration times before Rim fire. But it increased until 7 days and reduced or kept stable after that. Based on the 2014 average rainfall 1388 mm/yr, soil loss was estimated to be 247,518 ton/ha/yr before Rim Fire, and 9,389,937 ton/ha/yr after that.

Robotic rim deburring technique in car wheel (로보트 이용 자동차 휠의 림 디버링)

  • 박종오;전종업;조의경
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1991.10a
    • /
    • pp.1144-1148
    • /
    • 1991
  • The problems occurred when developing a automatic wheel deburring system are to make effective flexibility in model change and the irregularity of the position/shape of the burr, to select optimal robotic manufacturing process and to develope optimal end effector. The locations where burr exists are on flange, rim and spoke. Here will be discussed the optimal solution for the removal of rim burr by using robot. The research can be summarized as the automatic robot path generation by recognizing rim contour and automatic deburring process technique. Various rim contour data is generated automatically when the sensor which is fixed to robot is moving with the parallel motion to the wheel center axis and this generated data is transferred to the data storage system and converted to the robot path data. The robotic tool system which is suitable to the rim deburring process is developed by integrating tool, compliance function and sensor. And factory automation system controlled by robot controller and PC is developed. This system shows good productivity and flexibility.

  • PDF

New Hypothesis "Exhaustion of Diffusion-Contributable Vacancies in Core/Rim Structure"

  • Hayshi, Koji;Yanaba, Yutaka
    • Proceedings of the Korean Powder Metallurgy Institute Conference
    • /
    • 2002.11a
    • /
    • pp.8-8
    • /
    • 2002
  • TiC core/(Ti,Mo)C rim structure in TiC-$Mo_2C$-Ni base cermet which is generally prepared by sintering below 145$0^{\circ}C$ had been believed to be generated by the solid diffusion of Mo atoms 1 into TiC grains (D. Moskowitz and M.Humenik, 1r.:1966). Afterward, it was clarified that the c core/rim structure is generated by solution/re-precipitation mechanism : (1) $Mo_2C$ grains and s small TiC grains dissolve into the Ni liquid, (2) the dissolved Mo, Ti and C atoms migrate to the s surface of TiC coarse grains, (3) the Mo, Ti and C precipitate on the surface of TiC coarse g grains and form (Ti,Mo)C solid solution rim, and (4) the Ostwald ripening (grain growth by s solution/re-precipitation mechanism) of TiC-core/(Ti,Mo)-rim grains continues, and thus the w width of (Ti,Mo)C rim (at the same time, the grain size) increases with sintering time, etc. ( (H.Suzuki, K.Hayashi and O.Terada: 1973). The TiC-core was found not to disappear even by s sintering at 190$0^{\circ}C$ (ibid.: 1974) Recently, FeSi core/$Fe_2Si_5$-rim structure in Fe-66.7at%Si thermoelectric aIloy was found to also h hardly shrink and disappear by long heating at an appropriate temperature (1999: M.Tajima and K K.hayashD. Then, the authors considered its cause, and clarified experimentaIly that the disappearance of FeSi-core/$Fe_2Ski_5$-rim structure could be attributed to the exhaustion of diffusion-contributable vacancies in core/rim structure (N.Taniguchi and K.Hayashi:2001). At p present, the authors and my coworker are investigating whether the non-disappearance of TiC c core can be explained also from the new hypothesis "Exhaustion of diffusion-contributable v vacancies in corelrim structure".ure".uot;.

  • PDF

Modelling of Thermal Conductivity for High Burnup $UO_2$ Fuel Retaining Rim Region

  • Lee, Byung-Ho;Koo, Yang-Hyun;Sohn, Dong-Seong
    • Nuclear Engineering and Technology
    • /
    • v.29 no.3
    • /
    • pp.201-210
    • /
    • 1997
  • A thermal conductivity correlation has been proposed which can be applied to high turnup fuel by considering both of thermal conductivity with turnup across fuel pellet and additional degradation at pellet rim due to very high porosity. In addition, a correlation has been developed that can estimate the porosity of rim region as a function of rim burnup under the assumptions that all the produced fission gases are retained in the in porosity and threshold pellet average burnup required for the formation of rim region is 40 MWD/㎏U. Rim width is correlated to rim burnup using measured data. For the RISO experimental data obtained at pellet average turnup of 43.5 MWD/㎏U for three linear heat generation rates of 30, 35 and 40 ㎾/m, radial temperature distributions ore calculated using the present correlation and compared with the measured ones. This comparison shows that the present correlation gives the best agreement with the measured data when it is combined with the HALDEN's correlation for thermal conductivity considering its degradation with burnup. Another comparison with the HALDEN's measured fuel centerline temperature as a function of burnup at 25 ㎾/m up to about 44 MWD/㎾U also suggest that the present correlation yields the best agreement when it is combined with the HALDEN's thermal conductivity.

  • PDF

Determining of Ground Condition Criteria for Dam Reinforced RIM Grouting (댐체 강화 RIM부 그라우팅을 위한 지반상태 기준 결정)

  • Han, Kiseung;Lee, Donghyuk;Park, Duhee
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.42 no.2
    • /
    • pp.181-186
    • /
    • 2022
  • Dam slope RIM is a highly important contact interface where the main body and the base surface are connected. In general, when the grouting for the slope of the dam structure is designed, it is planned using limited data (drilling, geological map, etc.). This makes it very difficult to accurately consider the original ground characteristics of the slope RIM grouting target, In addition, when the grouting volume planned during the design is drilled and injected into the original ground where the waterstop is secured, there is a possibility that the original ground with the waterstop is disturbed and the effect of the waterstop is rather diminished. In order to overcome such problems, it is more suitable to first consider geological conditions and determine whether to perform optimal grouting on the original ground through on-site repair tests before performing RIM grouting. In this paper, to determine the grouting of the RIM unit, a pilot hole water pressure test was performed on the rock of the slope in the target section. The analysis shows grouting volume of 1 Lugeon or less, and the cement injection amount also shows the injection result of 1 kg/m or less. In this case, performing grouting is rather counterproductive. This result can be evaluated through a rock of which some degree of order of mass is secured, as it is a dam design standard of 1 Lugeon or less when analyzed, using the results of visual observation and geological map creation during slope cutting. Therefore, in conclusion, it is preferable to make the decision for using RIM grouting on the slope of the dam body structure, based on 1 Lugeon in a rock state, and the cement injection amount also at 1 kg/m.