TY - JOUR
T1 - A nonlinear fin design problem in determining the optimum shapes of fully wet annular fins
AU - Huang, Cheng Hung
AU - Chung, Yun Lung
N1 - Funding Information:
This work was supported in part through the National Science Council, ROC . Grant No. MOST-103-2221-E-006-234-MY3 .
Publisher Copyright:
© 2016 Elsevier Ltd. All rights reserved.
PY - 2016/6/25
Y1 - 2016/6/25
N2 - Because the thermal conductivity of an annular fin is a function of temperature in many practical engineering applications, the nonlinear optimum shape design problem is considered in this study. The conjugate gradient method (CGM) is utilized as the optimization tool based on the desired fin efficiency and fin volume. It is assumed that the surrounding air has 100% relative humidity, and thus an annular fin under fully wet conditions can be assured. The numerical experiment results show that the optimum annular fin has the highest fin efficiency among six annular fins with the same operating fin conditions. When the Biot numbers for ambient air (Bia) varied, the optimum fin efficiency and optimum fin shape of the nonlinear fully wet annular fin also changed significantly. However, when the nonlinearity of the Biot numbers for the inner tube (Bii), the thermal conductivities of the bare tube (kw) and the annular fin (kf) varied, the optimum fin shape remained almost the same. This implies that those three thermal parameters have a limited influence on the optimum fin shape for an annular fin and the results obtained from this work could be utilized directly to the evaporator manufacturing industries.
AB - Because the thermal conductivity of an annular fin is a function of temperature in many practical engineering applications, the nonlinear optimum shape design problem is considered in this study. The conjugate gradient method (CGM) is utilized as the optimization tool based on the desired fin efficiency and fin volume. It is assumed that the surrounding air has 100% relative humidity, and thus an annular fin under fully wet conditions can be assured. The numerical experiment results show that the optimum annular fin has the highest fin efficiency among six annular fins with the same operating fin conditions. When the Biot numbers for ambient air (Bia) varied, the optimum fin efficiency and optimum fin shape of the nonlinear fully wet annular fin also changed significantly. However, when the nonlinearity of the Biot numbers for the inner tube (Bii), the thermal conductivities of the bare tube (kw) and the annular fin (kf) varied, the optimum fin shape remained almost the same. This implies that those three thermal parameters have a limited influence on the optimum fin shape for an annular fin and the results obtained from this work could be utilized directly to the evaporator manufacturing industries.
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U2 - 10.1016/j.applthermaleng.2016.03.066
DO - 10.1016/j.applthermaleng.2016.03.066
M3 - Article
AN - SCOPUS:84971595267
VL - 103
SP - 195
EP - 204
JO - Journal of Heat Recovery Systems
JF - Journal of Heat Recovery Systems
SN - 1359-4311
ER -