• 제목/요약/키워드: Thermal Radiation Analysis

검색결과 481건 처리시간 0.028초

모터싸이클 디스크 브레이크의 열 및 응력 해석을 통한 형상 설계 (A Study on Shape Design of Motorcycle Disk using Thermal and Stress Analysis)

  • 강석현;박시형;이성수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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    • pp.363-368
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    • 2001
  • Studies on brake system recently are focused on braking performance, especially the consideration on safety of braking system in an extreme situation and reduction of vibration and noise during braking operation. The thermal crack and Judder from the friction between brake disc and pad can bring the threaten of passengers' safety in the end. Braking force comes from the change of kinetic energy to friction energy. Since heat energy is developed from here, the analysis on thermal stress and thermal strain can be the good data when selecting the material of brake pad and designing heat radiation holes on the disc and it will also be the data when designing the thickness of the disc. This paper is intended to show a creative design method by suggesting the thermal analysis data through FEM study and using shape design parameters.

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복사 차폐막이 극저온 용기의 부하에 미치는 영향에 관한 실험적 연극 (An Experimental Study on the Effects of a Radiation Shield on the Thermal Load of a Cryochamber)

  • 김영민;박성제;강병하
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.365-370
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    • 2005
  • Infrared (lR) detectors are widely used for such applications as thermoelstic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Cryochamber considers the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector Cryochamber with radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation. It is found that the thermal load can be substantially reduced by increasing the number of radiation shield.

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열복사를 고려한 열기계학적 해석을 위한 유한요소 부영역 결합법의 적용 (Subdomain-Based Finite Element Method for Thermomechanical Analysis with Thermal Radiation)

  • 신의섭;진지만
    • 대한기계학회논문집A
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    • 제30권6호
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    • pp.705-712
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    • 2006
  • A finite element method based on the penalized subdomain-interface framework is proposed for fully-coupled, nonlinear thermomechanical analyses with thermal contact anuor radiation boundaries. In the variational formulation, a well-known penalty functional scheme is adopted for connecting subdomains and interfaces that satisfy various continuity requirements. As a logical consequence, the whole domain can be arbitrarily divided into independently-modeled subdomains without considering the conformity of meshes along their interfaces. Since the nonlinearities due to the contact and radiation boundaries can be localized within a few subdomains, the computational efficiency of the present method is greatly increased with appropriate solution algorithms. By solving some numerical problems, these advantageous features are confirmed carefully.

접시형 태양열 흡수기의 Transient 열전달 특성에 대한 수치해석 연구 (Analysis of Transient Heat Transfer Characteristics of Dish-Type Solar Receiver System)

  • 이주한;서주현;오상준;이진규;서태범
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2094-2099
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    • 2008
  • A numerical and experimental studies are carried out to investigate the transient heat transfer characteristics of 5kWth dish-type solar air receiver. Measured solar radiation and temperatures at several different locations are used as boundary conditions for numerical simulation. Many parameters' effects (reflectivity of the reflector, the thermal conductivity of the receiver body, transmissivity of the quartz window, etc.) on the thermal performance are investigated. Discrete Transfer Method is used to calculate the radiation heat exchange in the receiver. A transient heat transfer model is developed and the rate of radiation, convection and conduction heat transfer are calculated. Comparing the experimental and numerical results, good agreement is obtained. Using the numerical model, the transient heat transfer characteristics of volumetric air receiver for dish-type solar thermal systems are known and the transient thermal performance of the receiver can be estimated.

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Analysis of the second grade fluid under the influence of thermal radiation with convective heat and mass transfer

  • Khurrum Fareed;Muzamal Hussain;Muhammad Taj;Abdelouahed Tounsi
    • Computers and Concrete
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    • 제34권3호
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    • pp.347-353
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    • 2024
  • This paper investigates the second-grade fluid between two parallel plates. Fluid is produced due to stretching. Convective heat and mass transfer features are elaborated with thermal and solutal stratification. Thermal radiation and chemical reactions are also assumed in heat and mass transport processes partial differential. Formulated non-linear partial differential equations are transformed into non-linear ordinary differential equations by utilizing the suitable transformation. Convergent series solutions are computed via Homotopy Analysis Method (HAM). Effects of Hartman number, temperature field, velocity distribution and Prandtl number are sketched and analyzed through graphs. It is noticed that velocity field first decreases and after some distance it shows increasing behavior by the increment.

복사 차폐막이 설치된 극저온 용기의 열부하 특성에 관한 실험적 연구 (An Experimental Study on the Thermal Load of a Cryochamber with Radiation Shields)

  • 김영민;강병하;박성제
    • 설비공학논문집
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    • 제20권1호
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    • pp.11-16
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    • 2008
  • Infrared (IR) detectors are widely used for such applications as thermoelastic stress analysis, medical diagnostics and temperature measurement. Infrared detectors commonly need to be refrigerated below 80 K, and thus a cooling system should be equipped together with the detector system. The cooling load, which should be removed by the cooling system to maintain the nominal operating temperature of the detector, critically depends on the insulation efficiency of the cryochamber housing the detector. Thermal load of a cryochamber is attributed to the conduction heat transfer through a cold finger, the gases conduction and radiation heat transfer. The thermal loads of an infrared detector cryochamber with a radiation shield are investigated experimentally in present study. Since the effect of radiation heat transfer on thermal loads is significant, radiation shields is installed in the cold finger part to protect heat input through radiation.

국내 태양열시스템 설치를 위한 시스템 최적 설치각 산출을 통한 최대 경사면일사량 분석 (Analysis of Maximum Solar Radiation on Inclined Surfaces for the Installation of Solar Thermal Systems in Korea Using the Optimum Installation Angle)

  • 조덕기;강용혁
    • 한국태양에너지학회 논문집
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    • 제29권2호
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    • pp.47-54
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    • 2009
  • The amount of incident rays over inclination according to direction has been widely utilized as important data m installing solar thermal systems. To optimize the incident solar radiation, the slope, that is the angle between the plane surface in question and the horizontal, and the solar azimuth angles are needed for these solar thermal systems. This is because the performance of the solar thermal systems in much affected by angle and direction of incident rays. Recognizing that factors mentioned above are of importance, actual experiment on the moving route of the sun have been performed in this research to obtain the angle of inclination with which the maximum incident rays can be absorbed. After all, the standard for designing highly optimized solar thermal systems will be provided for designers and employees working in the solar collector related industries.

메쉬 스크린을 적용한 해양구조물용 방풍 및 복사열 차단막 열유동특성에 관한 연구 (A Study on the Thermal and Flow Characteristics of Wind and Radiant Heat Shield for Offshore by using Mesh Screen)

  • 이중섭;진도훈
    • 한국기계가공학회지
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    • 제11권3호
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    • pp.166-173
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    • 2012
  • This study is about comparison of thermal and flow characteristics on the wind & radiant heat shield with STS mesh type screen for offshore. Numerical analysis was conducted to find transmission coefficient in the mesh and then analyse the flow characteristics about wind & radiant heat shield. The experiment method of solar radiation has been used as thermal radiation source to get the performance of radiant heat shield measurement. The sensor radiation device has been used to measure the reduction of solar radiation with various size of cells and at a distance of 0.5m and 1m from the cold face of the wind & radiant heat shield.

선체의 태양복사 열변형 해석을 위한 전처리시스템 (A System for Thermal Distortion Analysis of Hull Structures by Solar Radiation)

  • 하윤석;이동훈
    • 대한조선학회논문집
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    • 제53권4호
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    • pp.275-281
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    • 2016
  • One of the most important things for quality to meet ship-production schedule is an accuracy control. A ship is assembled by welding through whole production process, so it is important that loss by correction will not happen as much as possible by using some engineering skills like reverse design, reverse setting and margin for thermal shrinkage. These efforts are a quite effective in fabrication stages, but not in erection stages. If a ship block which consists of common steel is exposed to directional solar radiation, its dimensional accuracy will change high as time by its thermal expansion coefficient. Therefore, the measuring work would be often done at dawn or evening even with having a very accurate device. In this study, an FE analysis method is developed to solve this problem. It can change measured data affected by solar thermal distortion to ones not, even though ship-block is measured at an arbitrary time. It will use the time when measuring, the direction of block and the weather record by satellites. It is confirmed by a comparison between measured data of a ship-block and the result by suggested analysis method. Furthermore, a pre-processing system is also developed for fast application of the suggested analysis method.

유한요소법에 의한 평면 TV 새도우마스크의 열변형해석 및 전자빔 오착 예측 (Thermal Deformation Analysis of Shadow Mask in a Flat TV and Prediction of Electron Beam Landing Shift by FEM)

  • 김정;박수길;강범수
    • 대한기계학회논문집A
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    • 제26권11호
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    • pp.2297-2304
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    • 2002
  • Two-dimensional and three-dimensional finite element methods have been used to analyze the deformation behavior of a shadow mask due to thermal and tension load. The shadow mask inside the Braun tube of a TV set has numerous slits through which the electron beams are guided to land on the designed phosphor of red, green or blue. Its thermal deformation therefore causes landing shift of the electron beam and results in decolorization of a screen. For the realistic finite element analysis, the effective thermal conductivity and the effective elastic modulus arc calculated, and then the shadow mask is modeled as shell without slits. Next a transient thermal analysis of the shadow mask is performed, wherein thermal radiation is a major heat transfer mechanism. Analysis of the resulting thermal deformation is followed, from which the landing shift of the electron beam is obtained. The present finite element scheme may be efficiently used to reduce thermal deformation of a shadow mask and in developing prototypes of a large screen flat TV.