서지주요정보
난류 경계층내의 선형열원으로부터의 열확산 예측을 위한 난류모형 연구 = A study on turbulence models for prediction of heat dispersion from an elevated line source in a turbulent boundary layer
서명 / 저자 난류 경계층내의 선형열원으로부터의 열확산 예측을 위한 난류모형 연구 = A study on turbulence models for prediction of heat dispersion from an elevated line source in a turbulent boundary layer / 조중원.
발행사항 [대전 : 한국과학기술원, 1999].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8009557

소장위치/청구기호

학술문화관(문화관) 보존서고

MME 99074

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

리뷰정보

초록정보

An improved model to predict the heat dispersion from an elevated line source in a turbulent boundary layer is presented in consideration of temperature structure. Three development stages of heat dispersion behind a line source are discussed. Especially the initial stage in the region which is close to the source is hardly represented by the simple gradient-diffusion model. In this study an effective turbulent Prandtl number is introduced to describe the nonequilibrium turbulent temperature field near the source. At the initial stage, the meandering motion of a thin thermal plume dominates mean temperature and turbulent heat flux. The effective turbulent Prandtl number contains the effect that the meandering motion increases as fluid flows downstream. The developing process of the turbulent temperature field is characterized by the temporal integral Lagrangian scale at the source location. Therefore modeling of the effective turbulent Prandtl number also needs the Lagrangian information. The effective turbulent Prandtl number is used in energy equation and the turbulent eddy viscosity is estimated by using the low Reynolds number model. κ-ε model The model predictions are compared with experimental results. The predictions of a two-equation model for heat transport are also included for comparison. The comparison shows that the present model performance is in better agreement with experimental data than the latter method. In addition the model computation reveals that the maximum temperature decays with a power law, $Θ_{max}~Δx^{-1}$ in the intial stage and $Θ_{max}~Δx^{-0.7}$ in the final asymptotic stage.

서지기타정보

서지기타정보
청구기호 {MME 99074
형태사항 vi, 55 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Chung-Won Cho
지도교수의 한글표기 : 정명균
지도교수의 영문표기 : Myung-Kyoon Chung
학위논문 학위논문(석사) - 한국과학기술원 : 기계공학과,
서지주기 참고문헌 : p. 32-35
주제 난류
확산
프란틀수
라그랑지
선형열원
경계층
Turbulence
Dispersion
Prandtl number
Lagrange
Line heat source
Boundary layer
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