• Title/Summary/Keyword: Two-dimensional temperature distribution

Search Result 249, Processing Time 0.033 seconds

Two-dimensional Heat Conduction and Convective Heat Transfer a Circular Tube in Cross Flow (원관 주위의 2차원 전도열전달과 국소 대류열전달)

  • Lee Euk-Soo
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.29 no.1
    • /
    • pp.25-33
    • /
    • 2005
  • When a circular tube with uniform heat generation within the wall was placed in a cross flow, heat flows by conduction in the circumferential direction due to the asymmetric nature of the fluid flow around the perimeter of the circular tube The circumferential heat flow affects the wall temperature distribution to such an extent that. in some cases, significantly different results may be obtained for geometrically similar surfaces. In the present investigation, the effect of circumferential wall heat conduction is investigated for forced convection around circular tube in cross flow of air and water Two-dimensional temperature distribution $T_w(r,{\theta})$ is calculated through the numerical analysis. The difference between one-dimensional and two-dimensional solutions is demonstrated on the graph of local heat transfer coefficients. It is observed that the effect of working fluid is very remarkable.

Investigation of Local Convective Heat Transfer around a Circular Tube in Cross Flow of Air (원관 주위로 공기의 국소 대류 열전달에 대한 연구)

  • 이억수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.6
    • /
    • pp.546-555
    • /
    • 2004
  • With circular tube heated directly or indirectly placed in a cross flow, heat flows circumferentially by conduction due to the asymmetric nature of the fluid flow around the perimeter of the circular tube. The circumferential heat flow affects the wall temperature distribution to such an extent that in some cases. The effects of circumferential wall heat conduction on local convective heat transfer is investigated. The wall heat conduction parameter which can be deduced from the governing energy equation should be used to express the effect of circumferential heat conduction. Two-dimensional temperature distribution is presented through the numerical analysis. The comparison of one-dimensional and two-dimensional solutions is demonstrated on graph of local Nusselt numbers.

THEORITICALL ANALYSIS OF TEMPERATURE DISTRIBUTION IN TWO-DIMENSIONAL FIELD USING F.E.M (유한요소법을 이용한 2차원 Field 내의 온도분포의 이론적 해석)

  • Kim, N.H.;Choi, C.S.;Choi, H.H.;Hong, S.H.
    • Proceedings of the KIEE Conference
    • /
    • 1987.07b
    • /
    • pp.1292-1295
    • /
    • 1987
  • In noninvasive temperature measurement within body, this paper is presented temperature measurement method in security and with effect from Applicator by electromagnetic, and it is analyzed heat generation quantity or temperature rise distribution by computer simulation within body. In this paper, two-dimensional model is considered and temperature distribution produced by RF capacitive heating system is analyzed by using Finit Element Method (F.E.M). A passibility of temperature distribution control is examined based on the position and size of Applicator.

  • PDF

Heat Transfer Analysis in a Straight Fin of Trapezoidal Profile by the Heat Balance Integral Method (열평형적분법에 의한 사다리꼴단면의 직선휜에서의 열전달해석)

  • Jo Jong-Chull;Cho Jin-Ho
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
    • /
    • v.11 no.3
    • /
    • pp.1-8
    • /
    • 1982
  • When exact analytical solutions to certain type of heat conduction problems are quite cumbersome or not obtainable, it is important to introduce approximate analytical methods which are simple and useful compared with numerical methods. In this study, therefore, the Heat Balance Integral Method is applied to analysis of steady-state conduction in a straight fin of trapezoidal profile, and the two-dimensional temperature distribution in the fin and the approximate fin efficiency are obtained. Results are compared with those by the one- dimensional analysis and two-dimensional numerical analysis for a wide range of Biot numbers. It is shown that the two-dimensional temperature distribution obtained by the integral method is in good agreement with that by the finite element method at Biot numbers for which the result by the one-dimensional analysis is unreliable.

  • PDF

Conjugated heat transfer on convection heat transfer from a circular tube in cross flow (원관 주위의 대류 열전달에 대한 복합 열전달)

  • 이승홍;이억수;정은행
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.10 no.5
    • /
    • pp.523-534
    • /
    • 1998
  • The convection heat transfer on horizontal circular tube is studied as a conjugated heat transfer problem. With uniform heat generation in a cylindrical heater placed in a cross flow boundary condition, heat flow that is conducted along the wall of the heater creates a non-isothermal surface temperature and non-uniform heat flux distribution. In the present investigation, the effects of circumferential wall heat conduction on convection heat transfer are investigated for the case of forced convection around horizontal circular tube in cross flow of air and water. Non-dimensional conjugation parameter $ K^*$ which can be deduced from the governing energy differential equation should be used to express the effect of circumferential wall heat conduction. Two-dimensional temperature distribution$ T({\gamma,\theta})$ is presented. The influence of circumferential wall heat conduction is demonstrated on graph of local Nusselt number.

  • PDF

DEVELOPMENT OF A TWO-DIMENSIONAL THERMOHYDRAULIC HOT POOL MODEL AND ITS EFFECTS ON REACTIVITY FEEDBACK DURING A UTOP IN LIQUID METAL REACTORS

  • Lee, Yong-Bum;Jeong, Hae-Yong;Cho, Chung-Ho;Kwon, Young-Min;Ha, Kwi-Seok;Chang, Won-Pyo;Suk, Soo-Dong;Hahn, Do-Hee
    • Nuclear Engineering and Technology
    • /
    • v.41 no.8
    • /
    • pp.1053-1064
    • /
    • 2009
  • The existence of a large sodium pool in the KALIMER, a pool-type LMR developed by the Korea Atomic Energy Research Institute, plays an important role in reactor safety and operability because it determines the grace time for operators to cope with an abnormal event and to terminate a transient before reactor enters into an accident condition. A two-dimensional hot pool model has been developed and implemented in the SSC-K code, and has been successfully applied for the assessment of safety issues in the conceptual design of KALIMER and for the analysis of anticipated system transients. The other important models of the SSC-K code include a three-dimensional core thermal-hydraulic model, a reactivity model, a passive decay heat removal system model, and an intermediate heat transport system and steam generation system model. The capability of the developed two-dimensional hot pool model was evaluated with a comparison of the temperature distribution calculated with the CFX code. The predicted hot pool coolant temperature distributions obtained with the two-dimensional hot pool model agreed well with those predicted with the CFX code. Variations in the temperature distribution of the hot pool affect the reactivity feedback due to an expansion of the control rod drive line (CRDL) immersed in the pool. The existing CRDL reactivity model of the SSC-K code has been modified based on the detailed hot pool temperature distribution obtained with the two-dimensional pool model. An analysis of an unprotected transient over power with the modified reactivity model showed an improved negative reactivity feedback effect.

Wall Heat Conduction and Convection Heat Transfer from a Cylinder in Cross Flow (원형 실린더 주위의 전도-대류 열전달)

  • 이상봉;이억수;김시영
    • Journal of Ocean Engineering and Technology
    • /
    • v.15 no.3
    • /
    • pp.1-8
    • /
    • 2001
  • With uniform heat generation within the wall of the cylinder placed in a cross flow, heat flows by conduction in the circumferential direction due to the asymmetric nature of the fluid flow around the perimeter of the cylinder. The circumferential heat flow affects the wall temperature distribution to such an extent that in some cases significantly different results may be obtained for geometrically similar surfaces. In the present investigation, the effects of circumferential wall heat conduction on local convective heat transfer is investigated for the case of forced convection around horizontal cylinder in cross flow of air. Two-dimensional temperature distribution $T_w$/(${\gamma}$,${\theta}$) is presented through the numerical analysis. The one-dimensional and two-dimensional solutions are in good agreement with experimental results of local heat transfer coefficients.

  • PDF

Numerical Analysis for Sintering of Metal Powder Layers of the Direct Metal Prototyping (직접식 조형법의 금속 분말 적층부 소결에 관한 연구)

  • 손현기;양동열
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.04a
    • /
    • pp.552-556
    • /
    • 1997
  • The Direct Metal Prototyping(DMP), one of the rapid prototyping technologies, allows the manufacturing of three-dimensional metallic parts using metal powders directly from the CAD data. Laser power and scanning speed are the most important variables of the process. The objective of this study is to obtain the design data for laser power and scanning speed to bond metal powders effectively using the finite element method. To obtain the design values, a numerical analysis considering two-dimensional heat transfer during the sintering of metal powder layers of the process was performed. The laser beam has been modeled to have directionality in its heat flux distribution, i. e., in the scanning direction a Gaussian beam mode distribution has been assumed and in the thickness direction a square beam mode distribution. The three-dimensional irregular distribution of metal powders of the powder layer is idealized as two-dimensional distribution in which metal powders are located regularly and periodically on the plate. In this study the design values of laser power vs scanning speed have been obtained. Temperature distribution and temperature variation of the powder layers with respect to time have been predicted. The commputed dsign data will be useful in determining the initial conditions of the process.

  • PDF

Two-Dimensional Finite Element Analysis of Hot Radial Forging (열간반경단조의 2차원 유한요소해석)

  • 박치용;조종래;양동열
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.5
    • /
    • pp.1166-1180
    • /
    • 1990
  • The study is concerned with the two-dimensional thermo-viscoplastic finite element analysis for radial forging as an incremental forging process. The deformation and temperature distribution of the workpiece during radial forging are studied. The analysis of deformation and the analysis of heat transfer are carried out for simple upsetting of cylinder by decoupling the above two analyses. A method of treatment for heat transfer through the contact region between the die and the workpiece is suggested, in which remeshing of the die elements is not necessary. Radial forging of a mild steel cylinder at the elevated temperature is subjected to the decoupled finite element analysis as well as to the experiment. The computed results in deformation, load and temperature distribution are found to be in good agreement with the experimental observations. As an example of viscoplastic decoupled analysis of hot radial forging, forging of a square section into a circular section is treated. The stresses, strains, strain rates and temperature distribution are computed by superposing material properties as the workpiece is rotated and forged incrementally. It was been thus shown that proposed method of analysis can be effectively applied to the hot radial forging processes.

Modeling of transient temperature distribution in multilayer asphalt pavement

  • Teltayev, Bagdat B.;Aitbayev, Koblanbek
    • Geomechanics and Engineering
    • /
    • v.8 no.2
    • /
    • pp.133-152
    • /
    • 2015
  • Mathematical model has been developed for determination of temperature field in multilayer pavement and subgrade, which considers transfer of heat by conduction and convection, receiving of heat from total solar radiation and atmosphere emission, output of heat due to the emission from the surface of pavement. The developed model has been realized by the finite element method for two dimensional problem using two dimensional second order finite element. Calculations for temperature field have been made with the programme realized on the standard mathematical package MATLAB. Accuracy of the developed model has been evaluated by comparison of temperatures, obtained theoretically and experimentally. The results of comparison showed high accuracy of the model. Long-term calculation (within three months) has been made in pavement points in accordance with the data of meteorological station for air temperature. Some regularities have been determined for variation of temperature field.