• Title/Summary/Keyword: 역열전달

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Inverse Heat Transfer Analysis Using Monte Carlo Method in Gas-Filled Micro-Domains Enclosed by Parallel Plates (몬테카를로 방법을 이용한 기체로 채워진 평판 사이의 마이크로 역열전달 해석)

  • Kim, Sun-Kyoung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.7
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    • pp.657-664
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    • 2011
  • This study proposes an inverse method for estimating the boundary temperature in a gas-filled, onedimensional parallel domain enclosed by parallel plates. The distance between the plates is considered submicron to one mm. In the current method, it is assumed that the conditions of both heat flux and temperature are simultaneously applicable to one boundary, while no conditions are applicable to the other boundary The temperature on one of the boundaries should be inversely determined from the known temperature and heat flux on the other boundary. This study proposes a procedure for estimating the unknown boundary temperature through Monte Carlo simulation. Both the forward and inverse problems employ the Monte Carlo approach. The forward (direct) problem is solved by using the direct simulation Monte Carlo while the inverse solution is obtained by the simulated annealing.

Study on Estimations of Initial Mass Fractions of CH4/O2 in Diffusion-Controlled Turbulent Combustion Using Inverse Analysis (확산지배 난류 연소현상에서 역해석을 이용한 CH4/O2의 초기 질량분율 추정에 관한 연구)

  • Lee, Kyun-Ho;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.7
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    • pp.679-688
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    • 2010
  • The major objective of the present study is to extend the applications of inverse analysis to more realistic engineering fields with a complex combustion process rather than the traditional simple heat-transfer problems. In order to do this, the unknown initial mass fractions of $CH_4/O_2$ are estimated from the temperature measurement data by inverse analysis in the practical diffusion-controlled turbulent combustion problem. In order to ensure efficient inverse analysis, the repulsive particle swarm optimization (RPSO) method, which belongs to the class of stochastic evolutionary global optimization methods, is implemented as an inverse solver. Based on this study, it is expected that useful information can be obtained when inverse analysis is used in the diagnosis, design, or optimization of real combustion systems involving unknown parameters.

Estimation of Fire Dynamics Properties for Charring Material Using a Genetic Algorithm (유전 알고리즘을 이용한 탄화 재료의 화재 물성치 추정)

  • Chang, Hee-Chul;Park, Won-Hee;Lee, Duck-Hee;Jung, Woo-Sung;Son, Bong-Sei;Kim, Tae-Kuk
    • Fire Science and Engineering
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    • v.24 no.2
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    • pp.106-113
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    • 2010
  • Fire characteristics can be analyzed more realistically by using more accurate material properties related to the fire dynamics and one way to acquire these fire properties is to use one of the inverse property analyses. In this study the genetic algorithm which is frequently applied for the inverse heat transfer problems is selected to demonstrate the procedure of obtaining fire properties of the solid charring material with relatively simple chemical structure. The thermal decomposition on the surface of the test plate is occurred by receiving the radiative energy from external heat sources, and in this process the heat transfer through the test plate can be simplified by an unsteady 1-D problem. The inverse property analysis based on the genetic algorithm is then applied for the estimation of the properties related to the reaction pyrolysis. The input parameters for the analysis are the surface temperature and mass loss rate of the char plate which are determined from the unsteady 1-D analysis with a givenset of 8 properties. The estimated properties using the inverse analysis based on the genetic algorithm show acceptable agreements with the input properties used to obtain the surface temperature and mass loss rate with errors between 1.8% for the specific heat of the virgin material and 151% for the specific heat of the charred material.