• Title/Summary/Keyword: Misaligned plates

Search Result 5, Processing Time 0.02 seconds

Mixed convection heat transfer from vertically parallel and misaligned plates (수직 평판의 평행배열과 엇갈린 배열에서 혼합대류 열전달)

  • 김상영;정한식;권순석
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.15 no.3
    • /
    • pp.68-74
    • /
    • 1993
  • The mixed convection heat transfer has been studied numerically for misaligned and parrallel arrays of two flat plates at 100.leg.Re.leg.700, 0.1.leg.B.leg.1.0, 0.2.leg.leg.PHI.$_{R}$.leg.1Gr=10$^{4}$ and Pr=0.71. For misaligned plates and parallel plates, the optimum plate spacings move to the narrow spacing as Reynolds number and .PHI.$_{R}$ increase and can be expressed by the correlation equations at Gr=10$^{4}$. The optimum plate spacings for parallel plates sharply move to the narrow spacing compared with misaligned plates. The maximum mean Nusselt number of parallel plates shows higher value than that of misaligned plates and can be expressed by the correlation equations at Gr=10$^{4}$.EX>.

  • PDF

Mixed Convection Heat Transfer from Vertically Misaligned Isothermal plates (수직으로 엇갈린 등온평판에서의 혼합대류 열전도)

  • 권순석;김상영;박순업
    • Journal of Ocean Engineering and Technology
    • /
    • v.6 no.1
    • /
    • pp.52-61
    • /
    • 1992
  • The steady laminar mixed convection from vertically misaligned, isothermal plastes has been studied by numerical procedure. The governing equations are solved by the finite difference method using successive using successive over relaxation scheme at Re=100-800, $Gr=10^3-10^6$, Pr=0.71 and dimensionless plate spacings b/L=0.1-1.0. The plume interaction caused by the thermal interference of twoplates is observed. As Reynolds numbers increase, the optimum plate spacings are moved to narrow spacings at the same Grashof number and as Grashof numbers increase, to wide spacings at the same Reynolds number.

  • PDF

Osteotomy and iliac bone graft for the treatment of malunion caused by failed mandibular fracture reduction

  • Hwang, Kun;Ma, Sung Hwan
    • Archives of Craniofacial Surgery
    • /
    • v.21 no.6
    • /
    • pp.384-386
    • /
    • 2020
  • This report describes osteotomy and iliac bone graft for malunion caused by failed mandibular fracture reduction. A 27-year-old man was referred 3 months after a motor vehicle accident. At another hospital, two operations had been performed for symphyseal fracture using two resorbable plates. Malocclusion was noted, and panoramic radiography and computed tomography revealed a misaligned dental arch, with a 9.37-mm gap between the central and the lateral incisor of the left mandible. A wafer was made from the patient's dental model, and a maxillary arch bar was applied. Through a lower gingivolabial incision, osteotomy was performed between the malunited symphyseal fracture segments. Both segments were reduced to their original position using the wafer and fixed with titanium miniplates via intermaxillary fixation (IMF). The intersegmental gap was filled with cancellous bone from the iliac crest. The gingival defect was covered with a mucosal transposition flap from the gingivolabial sulcus. IMF and the wafer were maintained for 5 and 9 weeks, respectively. At postoperative week 13, the screws were removed from the mandible and satisfactory occlusion was noted. His mouth opening improved from 2.5 to 3 finger breadths (40 mm). This case demonstrates the need for sufficient IMF when using resorbable plates.

Experimental Study on the Characteristics of Misaligned Self-equalizing Tilting Pad Thrust Bearing (자려 평형 틸팅 패드 스러스트 베어링의 정렬불량에 따른 베어링 특성에 관한 실험적 연구)

  • Song, AeHee;Jo, HyunJun;Choi, SeongPil;Kim, SeonJin
    • Tribology and Lubricants
    • /
    • v.36 no.1
    • /
    • pp.27-33
    • /
    • 2020
  • Self-equalizing tilting pad thrust bearings are usually employed in turbomachines to achieve high stability and reliability. A tilting pad bearing can incorporate self-equalizing links to handle the misalignment between the bearing and the thrust collar. In this popular design method, the pads sit on the upper-level plates and the lower-level plates stay on the retainer base. With misalignment, the pads that are heavily loaded are pushed down. Consequently, the link pushes up the pads on the opposite side, keeping the bearing surface parallel to the thrust collar surface. The self-equalizing link is used to handle the misalignment from the thermal and mechanical effects. In this study, the experimental investigation deals with the performance of self-equalizing tilting pad thrust bearings. The test rig for evaluating the performance of bearing is developed which can control the misalignment angle. Simultaneous measurements are taken for the force acting on each pad. Pad metal temperature and oil film thickness are functions of the shaft speed, bearing load, misalignment angle, and design of leveling plates. The effect of misalignment on bearing performance is discussed. The results demonstrate that the load on each pad depends on the test conditions(especially misalignment angle), and the load influences the performance of bearings.

A Study of Shielding Plate Development for Backlight Control : With a Main Focus on 50W Misaligned LED Luminaires (후사광 제어를 위한 차광판 개발에 관한 연구 : 50W 급 비정렬 LED 조명기구를 중심으로)

  • Park, Tae-Yeon;Kim, Jung-Seok;Kim, Hway-Suh;Oh, Min-Seok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.28 no.11
    • /
    • pp.1-8
    • /
    • 2014
  • Recently, damages resulting from light trespass that affects the human body (sleep) as one of light pollution control elements of outdoor Luminaires equipment are leading to continuous civil complaints and disputes and this is gradually expanding into a social problem. Accordingly, this study considers the need to develop a shielding plate in consideration of light distribution performance as an efficient measure to cope with damages from light trespass. Therefore, this study developed a shielding plate for LED Luminaires with a fine view that maximally inhibited light toward the backlight area compared to existing shielding plates and verified its performance.