Inverse estimation of the local heat transfer coefficient in curved tubes: a numerical validation

31st UIT (Italian Union of Thermo-fluid-dynamics) Heat Transfer Conference 2013

Bozzoli, F.^1 ; Cattani, L.^1 ; Corradi, C.^2 ; Mordacci, M.^2 ; Rainieri, S.^1,2

Department of Industrial Engineering, University of Parma, Parco Area delle Scienze 181/A, I-43124 Parma, Italy^1

SITEIA.PARMA Interdepartmental Centre, University of Parma, Parco Area delle Scienze 181/A, I-43124 Parma, Italy^2

关键词: Centrifugal Forces;    Convective heat transfer;    Convective heat transfer Coefficient;    Inverse estimation;    Local distributions;    Local heat transfer coefficient;    Numerical validations;    Wall temperatures;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/501/1/012002/pdf
DOI  :  10.1088/1742-6596/501/1/012002

来源: IOP

【 摘 要 】

Wall curvature represents one of the most used passive techniques to enhance convective heat transfer. The effectiveness of wall curvature is due to the fact that it gives origin to the centrifugal force: this phenomenon induces local maxima in the velocity distribution that locally increase the temperature gradients at the wall by then maximizing the heat transfer. This fact brings to a significant variation of the wall temperature and of the wall heat flux along the circumferential coordinate. The convective heat transfer coefficient is consequently not uniformly distributed along the tube's perimeter and is characterized by higher values at the extrados wall surface in comparison to the ones at the intrados wall surface. Therefore, for predicting the overall performance of heat transfer apparatuses that involve the use of curved tubes, it becomes important to know the local distribution of the convective heat transfer coefficient not only along the axis of the heat transfer section, but also on the internal tube's surface along the cross section circumference. The present paper is intended to the assessment of a procedure developed to evaluate the local convective heat transfer coefficient, along the circumferential coordinate, at the internal wall of a coiled pipe.