Isıl parametreleri değişken olan dairesel kanatların parametrelerin değişimi yöntemi kullanılarak optimizasyonu

Yıl 2018, Cilt: 24 Sayı: 1, 1 - 7, 27.02.2018

Cihat Arslantürk

Öz

Bu
çalışmanın amacı, ısıl özelliklerin sıcaklıkla değiştiği dairesel kanatların
optimum tasarımı için, tasarımcıya kullanışlı korelasyon denklemleri sunmaktır.
Kanatların optimum boyutlarını elde etmek için kanattan olan ısı transferinin mümkün
olan en az kabulle hesaplanması gerekir. Bu nedenle, bu çalışmada ısı taşınım
katsayısı ve ısıl iletkenliğin sıcaklıkla değişimi göz önüne alınmış ve lineer
olmayan kanat denklemi, nonlinear problemlerin çözümünde kullanımı çok yeni
olan parametrelerin değişimi yöntemi ile çözülmüş, elde edilen sıcaklık
dağılımı yardımıyla kanattan çevreye olan ısı transfer hızı boyutsuz problem
parametreleri cinsinden hesaplanmıştır. Verilen problem parametreleri için ısı
transfer hızını maksimum yapan kanat geometrileri saptanmıştır. Kaynama, doğal
taşınım ve zorlanmış taşınımla ısı transfer modları için kullanılabilecek bu
sonuçlar iki eş korelasyon denklemi ile tasarımcının hizmetine sunulmuştur.

Anahtar Kelimeler

Dairesel kanatlar, Optimizasyon, Doğrusal olmayan diferansiyel denklemler, Değişken ısıl iletkenlik, Değişken ısı taşınım katsayısı

Variation of parameters method for optimizing annular fins with variable thermal properties

Öz

The aim of this study is to offer useful
correlation equations to the designer for the optimum design of annular fins
with thermal properties varying with temperature. In order to obtain the
optimum size of the fins, the heat transfer from the fin must be calculated
with the least assumptions possible. Therefore, the variation of the heat
transfer coefficient and thermal conductivity with the temperature are
considered in this study and a nonlinear fin equation is solved with the
variation of parameters method, which is quite new in the solution of nonlinear
heat transfer problems. Heat transfer rate from the fin to the environment is
calculated in terms of dimensionless problem parameters with the help of the
obtained temperature distribution. Fin geometries maximizing the heat transfer
rate are determined for the given problem parameters. These results, which can
be used for nucleate boiling, natural convection and forced convection heat
transfer modes, are offered to the designer with two identical correlation
equations.

Anahtar Kelimeler

Annular fins, Optimization, Variable thermal conductivity, Nonlinear differential equations, Variable heat transfer coefficient, Variation of parameters method

Kaynakça

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