• Title/Summary/Keyword: Mean-line Analysis

Search Result 442, Processing Time 0.029 seconds

Throughflow Analysis of Axial Flow Turbines - Comparison of Multi-streamline and Mean Line Methods - (축류터빈의 관통유동해석 - 다유선해석과 평균반경해석의 비교분석 -)

  • Kim, Tong Seop
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.22 no.8
    • /
    • pp.1173-1182
    • /
    • 1998
  • A throughflow analysis program for axial flow turbines is constructed, which can handle not only the two-dimensional multi-streamline (streamline curvature) method but also the one-dimensional mean line method. Calculations are performed for single stage and multi-stage axial flowturbines. For a wide operating range, the performance and flow field calculated by the present streamline curvature method are close enough to the test data. It is also revealed for the single stage turbine that the present analysis leads to far better correspondence with the experiment than other researchers" throughflow analyses. A special focus is put on the comparison of the results between the streamline curvature analysis and the mean line analysis. It is found that the mean line analysis can not predict the performance for highly off-designed conditions as accurately as the streamline curvature method, which shows the importance of considering the spanwise variation of loss and flow.

Axial-Compressor Design with Mean-line Analysis and Vortex Method (평균유속법과 Vortex 방법을 사용한 축류압축기 설계)

  • Choi, Min-Suk;Yoon, Sugn-Ho;Baek, Je-Hyun
    • Proceedings of the KSME Conference
    • /
    • 2001.06e
    • /
    • pp.795-800
    • /
    • 2001
  • In this study, a program to design a multi-stage axial compressor is developed wi th mean-line analysis and vortex methods. In a preliminary design stage, a method. to design in a short time is needed and mean-line analysis is usually used for this purpose. Arbitrary pressure ratio and reaction can be assigned to generate overall geometry and several vortex methods are adopted to consider the radial distribution of velocity and reaction. The variation of performance, when we use free vortex, forced vortex, and exponential method, is compared and discussed.

  • PDF

FE-based Strip Mean Temperature Prediction On-Line Model in Hot Strip Finishing Mill by using Dimensional Analysis (차원해석을 통한 열간 사상압연중 온도해석모델 개발)

  • 이중형;곽우진;황상무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2003.05a
    • /
    • pp.176-179
    • /
    • 2003
  • The mean temperature prediction of strip is very important in hot strip finishing mill because of affecting on product quality and shape. Also, temperature can be used by basic information in other on-line control models with affecting control accuracy in factory. So, FE based on-line temperature model was developed for predicting strip mean temperature accurately in various process conditions and factory environments. There are many variables in affecting strip mean temperature in on-line states of factory. But some problems are occurred in considering all variables for making temperature model because of the bad efficiency of regression or fitting analysis. In this report, we have adopted dimensional analysis for solving these problems. We have many variables with dimensions affecting strip temperature but we are able to make non-dimensional variables less than dimensional variables from the combination of dimensional variables caused by PI-Theorem in fluid mechanics. The developed models are divided by two parts. The one is interstand temperature prediction model. The other is roll gap temperature model.

  • PDF

A Study on the Morphological Diagrgmmings of Four Constitutiens (사상인(四象人)의 형태학적(形態學的) 도식화(圖式化)에 관(關)한 연구(硏究))

  • Huh, Man Hoee;Song, Jeong-Mo;Kim, Dal-Rae;Go, Byeong-Hui
    • Journal of Sasang Constitutional Medicine
    • /
    • v.4 no.1
    • /
    • pp.107-148
    • /
    • 1992
  • The definitions of Four Constitution (Tae-Yang-In, So-Yang-In, Tae-Eum-In, So-Eum-In) in Four-Beginning-Theory (四端論) and Distribution-Theory (擴充論) were morphologically diagrammatized. the method of measuring the five parts came from the diagrams. The five parts are the followings; Top-Line is the distance between Rt. & Lt.Shoulders. Bosom-Line is the horizontal distance passing through the Rt. & Lt.nipples. Stomach-Line is the horizontal distance passing through the Rt. & Lt. acupuncture point Bool-Yong (不容穴). Navel-Line is the horizontal distance passing through the navel. Bottom-Line is the distance between the Rt.& Lt. anterior superior iliac spines. According to it, 311 people were measured in the clinic. Through the measured numerical values, to find out the objective propriety of the morphological diagrammings and the discriminating ability of Four Constitutions by the method of measuring the five, the author tried this study and got the following results. 1. On the ground of the Internal Organs-Theory (臟腑論), the definitions of Four Constitutions were classified and diagrammatized step by step and it was possible to draw the morphological graphs satisfying the reasonable condition objectively. 2. It was found that the graphings by Mean, Standard Deviation and 95% Confidence Interval for mean of the numerical values of five measured parts and the morphological diagrammings of the definitions in Four-Beginning Theory and Distribution-Theory drove to the same figures. 3. Through the method of the Analysis of variance and the Discriminant Analysis, it was discovered that the measured numerical values of five parts could distinguish the Four Constitutions. 4. Tae-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of Confidence Interval from Top to Bottom is downwardly decreased at the rate of 3.7, 1.5, 1.8, 3.4. 5. So-Yang-In has the longest Top-Line and the shortest Bottom-Line. The Mean head of confidence Interval from Top to Bottom is downwardly decreased at the rate of 2.3, 1.5, 1.5, 1.1. 6. Tae-Eum-In has the longest Navel-Line. The Mean head of Confidence Interval from Navel to Top is upwardly decreased at the rate of 0.5, 0.4, 2.5 and downwardly decreased at the rate of 2.7 between Navel and Bottom. 7. So-Eum-In has the longest Bottom-Line. The Mean head of Confidence Interval from Bottom to Top is upwardly decreased at the rate of 1.1, 1.1, 1.8, 2.3. From the above findings, it was possible to draw the morphological graphings satisfying the objectively reasonable conditions in the definitions of Four-Beginning-Theory and Distribution-Theory and it was proved that the results of the Positive Analysis, carried with the measured numerical values of five parts from the diagramming, could show the objective propriety of the morphological graphings and the discerning ability of Four Constitutions by the method of measuring the five parts.

  • PDF

Queueing Analysis by Menu Management Systems in Cafeteria of the Business Foodservices (카페테리아 식단을 제공하는 사업체 급식소의 식단운영 형태에 따른 대기행렬 분석)

  • 양일선
    • Journal of Nutrition and Health
    • /
    • v.31 no.8
    • /
    • pp.1347-1354
    • /
    • 1998
  • The purposes of this study were to : (a) anlayze wating time, service rate, arrival rate, and coustomer expectations/satisfaction in cafeteria business foodservices and (b) identify the differences in those factors between foodservices by menu managmenet systems. The samples were two business foodservices operated by contract management in Seoul. The queue, laptime , service rate, and arrival rate were measured at each foodservice by stopwatch observation. The menu type, delivery system, number of meals served , servide time, and turnover rate of each foodservic was investigated. Questionnaires were developed to survey customer expectations and satisfaction. Satistical data analysis was completed using the SAS package programs for descriptive analysis and t-test. The mean waiting time of island type dafeteria system with separte set -menu was shorter than that of the other. In both foodservices, arrival rates were not significantly different from one another , but sevice rates were significnatly high in dafeteria menu systems. The peak time of the queue was found out at combination set menu line. The separate set menu line had a higher servide rate than the combination set menu line. The mean waiting time of the island type cafeteria line was shorter than that of the straifth type . At the straight type dafeterial line, both arrival rate and service rate were higher than those of island-type. The results of this study suggested that a separate set-menu would be more desirable than a combination set-menu in case of providing set menu with cafeteria menu.

  • PDF

Development of Axial Compressor Design and Performance/Flow Analysis Program (축류 압축기 설계 및 성능/유동 해석 프로그램 개발)

  • Yoon, S.H.;Lee, K.Y.;Park, J.Y.;Park, T.J.;Choi, M.S.;Baek, J.H.
    • Proceedings of the KSME Conference
    • /
    • 2001.11b
    • /
    • pp.658-663
    • /
    • 2001
  • In this study, the axial-compressor design and performance/flow analysis program is developed. A mean-line analysis was used to determine optimum arrangement of overall geometry and its off-design performance is predicted by stage-stacking method. Three dimensional blade shape is generated using radial equilibrium equation and vortex methods. Various blade shape is generated and their performance is compared. Finally the quasi-three dimensional flow analysis is applied to investigate the detailed flow phenomena.

  • PDF

A study on the sheet drawing using the Matrix method (Matrix법을 이용한 판재 인발에 관한 연구)

  • 유홍균;전병희
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.13 no.6
    • /
    • pp.90-100
    • /
    • 1991
  • This paper represents the analysis of the sheet drawing by applying the Matrix method to Hill's slip-line field for small reduction and indirect type slip-line field in case of large reduction. Results of the analysis represent the relation between the reduction ratio and the die wall pressure, mean drawing stress through rough die. The limitation on the use of this slip-line field is described. When the reduction ratio is given, the optimum die angle is analyzed in this paper.

  • PDF

Cephalometrically assessing the validity of superior, middle and inferior tragus points on ala-tragus line while establishing the occlusal plane in edentulous patient

  • Chaturvedi, Saurabh;Thombare, Ram
    • The Journal of Advanced Prosthodontics
    • /
    • v.5 no.1
    • /
    • pp.58-66
    • /
    • 2013
  • PURPOSE. The purpose of this study was to decide the most appropriate point on tragus to be used as a reference point at time of marking ala tragus line while establishing occlusal plane. MATERIALS AND METHODS. The data was collected in two groups of subjects: 1) Dentulous 2) Edentulous group having sample size of 30 for each group with equal gender distribution (15 males, 15 females each). Downs analysis was used for base value. Lateral cephalographs were taken for all selected subjects. Three points were marked on tragus as Superior (S), Middle (M), and Inferior (I) and were joined with ala (A) of the nose to form ala-tragus lines. The angle formed by each line (SA plane, MA plane, IA plane) with Frankfort Horizontal (FH) plane was measured by using custom made device and modified protractor in all dentulous and edentulous subjects. Also, in dentulous subjects angle between Frankfort Horizontal plane and natural occlusal plane was measured. The measurements obtained were subjected to the following statistical tests; descriptive analysis, Student's unpaired t-test and Pearson's correlation coefficient. RESULTS. The results demonstrated, the mean angle COO (cant of occlusal plane) as $9.76^{\circ}$, inferior point on tragus had given the mean angular value of IFH [Angle between IA plane (plane formed by joining inferior point-I on tragus and ala of nose- A) and FH plane) as $10.40^{\circ}$ and $10.56^{\circ}$ in dentulous and edentulous subjects respectively which was the closest value to the angle COO and was comparable with the values of angle COO value in Downs analysis. Angulations of ala-tragus line marked from inferior point with occlusal plane in dentulous subject had given the smallest value $2.46^{\circ}$ which showed that this ala-tragus line was nearly parallel to occlusal plane. CONCLUSION. The inferior point marked on tragus is the most appropriate point for marking ala-tragus line.

VALIDITY OF POSTERIOR ANTERIOR CEPHALOMETRIC AND 3D-CT FOR ORBITAL CANTING ANALYSIS (안와 경사의 분석을 위한 정모 두부규격방사선사진, 3D-CT의 유용성 평가)

  • Kim, Jin-Wook
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.30 no.6
    • /
    • pp.546-553
    • /
    • 2008
  • Purpose: The purpose of this study was to estimate validity of posterior anterior cephalometric and 3D-CT for orbital canting analysis. Materials and methods: Three trained observers classified two patients group using standardized frontal photographs of facial asymmetry patients. Group A consisted of patients with facial asymmetry and orbital canting(n=19), and group B consisted of patients with only facial asymmetry(n=43). Orbital canting was measured with line of bilateral inferior orbitale. Orbital canting measurement was done with posterior anterior cephalometric and 3D-CT. Each horizontal reference line was established by bilateral GWSO(cephalometric), FZS(3D-CT). Maxillary canting and mandibular deviation angle were also measured and analyzed with orbital canting. Results: The mean orbital canting was $3.03{\pm}1.00^{\circ}$ in Group A and $1.11{\pm}0.76^{\circ}$ in Group B in frontal photograph. The mean orbital canting was $1.20{\pm}0.74^{\circ}$ in group A and $1.22{\pm}0.65^{\circ}$ in group B by cephalometric analysis(p>0.05). In 3D-CT, orbital canting was almost paralleled with horizontal reference line. The orbital canting, maxillay canting and mandibular deviation between two groups showed no significant differences except madibular deviation in 3D-CT. Conclusion: Common analysis of posterior anterior cephalometric and 3D-CT is not valide method to evaluate orbital canting for facial asymmetry patients with orbital canting.

Review of the Improvement Plans on Catenary Systems for Speed Increase in Gyeongbu High-Speed Line

  • Eum, Ki Young;Yun, Jangho;Lee, Kiwon;Kim, Jung Hwan
    • International Journal of Railway
    • /
    • v.6 no.2
    • /
    • pp.64-68
    • /
    • 2013
  • In recent years, the speed of a train has been recognized as one of the important factors to determine the competitiveness as a mean of transportation. In line with this, infrastructure improvements and enhancements are being made with increases in the speed of train. Accordingly, there is a need to establish plans for infrastructure improvements through a comprehensive analysis of signals, track/civil engineering, catenary and environment, etc. to improve the speed of a train of high-speed train service sections in Korea. This study proposes improvement plans for catenary systems by investigating the possibility of improvements through performance analysis of catenary equipment by speed increase based on the analysis on catenary systems in Gyeongbu high-speed line, and analysis the applicability of catenary improvements and economic feasibility.