• Title/Summary/Keyword: Inclination angles

Search Result 236, Processing Time 0.03 seconds

Film Cooling from Two Rows of Holes with Opposite Orientation Angles: Blowing Ratio Effects (반대방향의 방향각을 갖는 2열 분사구조의 막냉각 특성 : 분사비의 영향)

  • Ahn, J.;Jung, I.S.;Lee, J.S.
    • Proceedings of the KSME Conference
    • /
    • 2000.04b
    • /
    • pp.113-118
    • /
    • 2000
  • Experimental results describing the effects of blowing ratio on film cooling from two rows of holes with opposite orientation angles are presented. The inclination angle was fixed at $35^{\circ}$ and the orientation angles were set to be $45^{\circ}$ for downstream row. and $-45^{\circ}$ for upsream row. The studied blowing ratios were 0.5, 1.0 and 2.0. The boundary layer temperature distributions were measured using thermocouple at two downstream loundary layer temperature distributions were measured using thermocouple at two downstream locations. Detailed adiabatic film cooling effectiveness and heat transfer coefficient distributions were measured with TLC(Thermochromic Liquid Crystal). The adiabatic film cooling effectiveness and heat transfer coefficient distributions are discussed in connection with the injectant behaviors inferred from the boundary layer temperature distributions. Film cooling performance, represented by heat flux was calculated with the adiabatic film cooling effectiveness and heat transfer coefficient data.

  • PDF

The Comparison on Resistance Performance and Running Attitude of Asymmetric Catamaran Changing Angle of Inclination of Tunnel Stern Exit Region (비대칭 고속 쌍동선의 선미터널 출구영역의 경사각 변화에 따른 저항성능 및 항주자세 분석)

  • Kim, Sang-Won;Seo, Kwang-Cheol;Cho, Dea-Hwan;Kim, Byung-Jae;Lee, Gyeong-Woo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2017.11a
    • /
    • pp.232-233
    • /
    • 2017
  • In this research, tunnel stern was applied on the asymmetric high-speed catamaran to evaluate vessel's hydrodynamic performance by numerical method, and the tunnel stern types are distinguished by angle of inclination of tunnel exit region into 3cases ($0^{\circ}$, $3^{\circ}$ and $6^{\circ}$). Consequently, it is confirmed that the total resistances of tunnel stern which have $0^{\circ}$ of inclination are lower about 4.8-17.9% than the bare hull in the wide speed range, but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are higher than bare hull about 5-14% and 5-29%, respectively. On the other hand, trim angles of $0^{\circ}$ of inclination tunnel stern show similar trend with those of bare hull in whole ranges of FnV but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are stabilized and declined respectively after FnV=1.54. These phenomena indicated that increasing angle of inclination of tunnel exit region had negative influence on resistance performance, however, it could make vessel's operation performance better than bare hull.

  • PDF

Dry matter and grain production of a near-isogenic line carrying a 'Takanari' (high yielding, Indica) allele for increased leaf inclination angle in rice with the 'Koshihikari' (Japonica) genetic background

  • San, Nan Su;Otsuki, Yosuke;Adachi, Shunsuke;Yamamoto, Toshio;Ueda, Tadamasa;Tanabata, Takanari;Ookawa, Taiichiro;Hirasawa, Tadashi
    • Proceedings of the Korean Society of Crop Science Conference
    • /
    • 2017.06a
    • /
    • pp.32-32
    • /
    • 2017
  • To increase rice production, manipulating plant architecture, especially developing new high-yielding cultivars with erect leaves, is crucial in rice breeding programs. Leaf inclination angle determines the light extinction coefficient (k) of the canopy. Erect leaves increase light penetration into the canopy and enable dense plantings with a high leaf area index, thus increasing biomass production and grain yield. Because of erect leaves, the high-yielding indica rice cultivar 'Takanari' has smaller k during ripening than 'Koshihikari', a japonica cultivar with good eating quality. In our previous study, using chromosome segment substitution lines (CSSLs) derived from a cross between 'Takanari' and 'Koshihikari', we detected seven quantitative trait loci (QTLs) for leaf inclination angle on chromosomes 1 (two QTLs), 2, 3, 4, 7, and 12. In this study, we developed a near-isogenic line (NIL-3) carrying a 'Takanari' allele for increased leaf inclination angle on chromosome 3 in the 'Koshihikari' genetic background. We compared k, dry matter production, and grain yield of NIL-3 with those of 'Koshihikari' in the field from 2013 to 2016. NIL-3 had higher inclination angles of the flag, second, and third leaves at full heading and 3 (- 4) weeks after full heading and smaller k of the canopy at the ripening stage. Biomass at full heading and leaf area index at full heading and at harvest did not significantly differ between NIL-3 and 'Koshihikari'. However, biomass at harvest was significantly greater in NIL-3 than in 'Koshihikari' due to a higher net assimilation rate at the ripening stage. The photosynthetic rates of the flag and third leaves did not differ between NIL-3 and Koshihikari at ripening. Grain yield was higher in NIL-3 than 'Koshihikari'. Higher panicle number per square meter in NIL-3 contributed to the higher grain yield of NIL-3. We conclude that the QTL on chromosome 3 increases dry matter and grain production in rice by increasing leaf inclination angle.

  • PDF

Effects of Transversus Abdominal Muscle Stabilization Exercise to Spinal Segment Motion on Trunk Flexion-Extension (복횡근 강화운동이 체간 신전-굴곡 시 척추 분절 운동에 미치는 영향)

  • Kim, Suhn-Yeop;Baek, In-Hyeub
    • Physical Therapy Korea
    • /
    • v.10 no.1
    • /
    • pp.63-76
    • /
    • 2003
  • This research was performed to compare spinal segment motion angle between low back pain (LBP) group and painless group during trunk flexion-extension and to investigate the effect of transversus abdominis strengthening exercise on spinal segment motion angle in LBP group. Nine subjects with LBP and ten subjects without LBP participated. Transversus abdominis strengthening exercise was performed in LBP group for three weeks, and spinal segment motion angles were compared before and after the exercise performance. Spinal segment motion angles were measured both in sitting and standing position. Results were as followed: 1) Subjects' average age was 24.79 years, height was 167.84 cm, and weight was 59.95 kg. 2) Spinal segment motion angle of T10/l1 was significantly higher in LBP group compared with painless group (p<.05) in sitting position during trunk flexion-extension. 3) In sitting position, whereas entire lumbar segment motion angles were lower in LBP group compared with painless group (p<.05), angle of L4/5 was higher in LBP group compared with painless group (p<.05). 4) There was no significant difference in thoracic segment motion angle in standing position. 5) After three weeks of transversus abdominis strengthening exercise, thoracic segment motion angle increased both in sitting and standing position (p<.05). 6) In painless group, there was no significant difference in entire spinal segment motion angles in sitting and standing position (p>.05). When spinal segment motion angles were compared between sitting and standing position, there were slight differences. In sitting position, there was no difference in spinal segment motion angle between LBP group and painless group while hip joint motion angle and sacral inclination angle of LBP group was lower than those of painless group (p<.05). In standing position, lumbar segment motion angle was significantly lower in LBP group than that of painless group. Transversus abdominis strengthening exercise influenced thoracic segment motion angle more significantly than lumbar segment motion angle.

  • PDF

3-Dimensional analysis for class III malocclusion patients with facial asymmetry

  • Kim, Eun-Ja;Ki, Eun-Jung;Cheon, Hae-Myung;Choi, Eun-Joo;Kwon, Kyung-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.39 no.4
    • /
    • pp.168-174
    • /
    • 2013
  • Objectives: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. Results: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). Conclusion: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.

Conversion of 3-Component Magnetic Data into Geodetic Coordinate System by Using Clinometer and GNSS Compass (경사계와 GNSS 나침반을 이용한 3성분 자력 탐사자료의 측지 좌표계로의 변환 방법)

  • Jeon, Tae-Hwan;Rim, Hyoungrea;Park, Young-Sue;Lim, Muteak;Shin, Young-Hong
    • Geophysics and Geophysical Exploration
    • /
    • v.16 no.2
    • /
    • pp.91-96
    • /
    • 2013
  • This study proposes a method to correct inclination of instrument during exploration with a biaxial clinometer and GNSS compass. In 3-component magnetometry, measured vectors are ordinarily described in randomly inclined observation coordinate system due to movement, vibration, and shaking of instrument. Therefore, rotation angles of observation plane are needed to transform it into geodetic coordinate system. In this study, we measured inclination angles of observation plane by using 2-axis clinometer and GNSS compass, and derived proper parameters for rotational transform from them. We applied the conversion method to on-board 3-component magnetometry, and then transformed raw data into proper values on geodetic coordinate system.

Study on the Capillary Limitation in Copper-Water Heat Pipes with Screen Wicks

  • Park, Ki-Ho;Lee, Ki-Woo;Noh, Seung-Yong;Rhi, Seok-Ho;Yoo, Seong-Yeon
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.12 no.1
    • /
    • pp.21-29
    • /
    • 2004
  • This paper is to study the heat transfer performance of the copper-water heat pipe with screen wicks. Recently, the semiconductor capacity of an electronic unit becomes larger, but its size becomes much smaller. As a result, a high- performance cooling system is needed. Experimental variables are inclination angles, temperatures of cooling waters and the mesh number of screen wicks. The distilled water was used as a working fluid. Based on the experimental results, when the copper-water heat pipe of 6mm diameter is used at the top heat mode, the heat transfer performance of 100 mesh 2 layers heat pipe is better than that of 150 and 200 mesh. The thermal resistance of the two layers with the 100-mesh screen was 0.7-$0.8^{\circ}C$/W.

Computation of Nonlinear Hydrostatic Force and Position of a Floating Structure Considering the Coupled Large Inclined Angles (연성된 과대 경사 각도를 고려한 부유식 구조물의 비선형 유체정역학 힘과 자세)

  • Cha, Ju-Hwan;Ku, Namkug;Park, Kwang-Phil
    • Korean Journal of Computational Design and Engineering
    • /
    • v.21 no.1
    • /
    • pp.90-98
    • /
    • 2016
  • When ships and offshore plants are flooded or the floating crane is equipped with a heavy object, these floating structures are excessively inclined. In this case, immersion, heel, and trim affecting the hydrostatic restoration performance are very large and are coupled each other. In this paper, in order to calculate a static equilibrium position of floating structures with excessive inclination, the nonlinear governing equations were constructed by sequential linearization. In the governing equation, the immersion, heel, and trim are fully coupled, and the equations are represented using a plane area, a primary moment, and a moment of inertia of the water plane area. Therefore, it is possible to calculate the additional factor related the water plane area for estimating stability. Position and orientation of the floating structure are obtained by iterative calculation. The calculated results are compared with the previous studies in the aspect to the performance and the accuracy.

Aerodynamic coefficients of inclined and yawed circular cylinders with different surface configurations

  • Lin, Siyuan;Li, Mingshui;Liao, Haili
    • Wind and Structures
    • /
    • v.25 no.5
    • /
    • pp.475-492
    • /
    • 2017
  • Inclined and yawed circular cylinder is an essential element in the widespread range of structures. As one of the applications, cables on bridges were reported to have the possibility of suffering a kind of large amplitude vibration called dry galloping. In order to have a detailed understanding of the aerodynamics related to dry galloping, this study carried out a set of wind tunnel tests for the inclined and yawed circular cylinders. The aerodynamic coefficients of circular cylinders with three surface configurations, including smooth, dimpled pattern and helical fillet are tested using the force balance under a wide range of inclination and yaw angles in the wind tunnel. The Reynolds number ranges from $2{\times}10^5$ to $7{\times}10^5$ during the test. The influence of turbulence intensity on the drag and lift coefficients is corrected. The effects of inclination angle yaw angle and surface configurations on the aerodynamic coefficients are discussed. Adopting the existed the quasi-steady model, the nondimensional aerodynamic damping parameters for the cylinders with three kinds of surface configurations are evaluated. It is found that surface with helical fillet or dimpled pattern have the potential to suppress the dry galloping, while the latter one is more effective.

Turbulent Natural Convection in a Square Enclosure Containing Internal Heat Generating Fluid (내부 발열유체를 가진 정사각 밀폐공간에서의 난류자연대류)

  • 이재헌;김석현;정종화;박만흥
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.16 no.1
    • /
    • pp.112-121
    • /
    • 1992
  • A numerical analysis was carried out to study two-dimensional turbulent natural convection in a square enclosure containing fluid of Prandtl number 6.05 within internal energy sources. The square enclosure was bounded by four rigid planes of constant equal temperature. Inclination angles of 0, 15, 30 and 45 deg. from the horizon for Rayleigh numbers from 1 * 10$^{6}$ to 1 * 10$^{9}$ were studied. Local and average Nusselts numbers are obtained on all four walls. If inclination angle exists, the average Nusselt number appears in increasing order at bottom, left, right and top wall.