翻訳と辞書 Words near each other ・ Annuario della Nobiltà Italiana ・ Annuario Pontificio ・ Annubar ・ Annuello, Victoria ・ Annuit cœptis ・ Annuitant ・ Annuity ・ Annuity (American) ・ Annuity (disambiguation) ・ Annuity (European) ・ Annuity function ・ Annular cutter ・ Annular dark-field imaging ・ Annular elastolytic giant-cell granuloma ・ Annular erythema of infancy ・ Annular fin ・ Annular fluidized bed ・ Annular lake ・ Annular ligament (disambiguation) ・ Annular ligament of radius ・ Annular ligament of stapes ・ Annular ligaments of fingers ・ Annular ligaments of toes ・ Annular lipid shell ・ Annular pancreas ・ Annular pustular psoriasis ・ Annular tropical cyclone ・ Annular velocity ・ Annularia ・ Annularisca Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Annular fin ： ウィキペディア英語版 Annular fin In thermal engineering, an annular fin is a specific type of fin used in heat transfer that varies, radially, in cross-sectional area. Adding an annular fin to an object increases the amount of surface area in contact with the surrounding fluid, which increases the convective heat transfer between the object and surrounding fluid. Because surface area increases as length from the object increases, an annular fin transfers more heat than a similar pin fin at any given length. Annular fins are often used to increase the heat exchange in liquid–gas heat exchanger systems. == Governing Equation == To derive the governing equation of an annular fin, certain assumptions must be made. The fin must have constant thermal conductivity and other material properties, there must be no internal heat generation, there must be only one-dimensional conduction, and the fin must be at steady state. Applying the energy conservation principle to a differential element between radii ''r'' and ''r'' + Δ''r'' yields :$$ q(2\pi r)(2t)\Bigr|_ - q(2\pi r)(2t)\Bigr|_ - h_c (2) 2\pi r\, \Delta r \left( T - T_e \right) = 0, where the first two terms are heat transferred through conduction, while the third is heat lost due to convection with the surrounding fluid. ''T'' represents the temperature at ''r'' and ''T''e represents the temperature of the surrounding fluid. Next, applying Fourier's law :$q\; =\; -k\; \backslash frac$ and dividing by 4πΔ''r'', letting Δ''r'' → 0, yields :$$ \frac \left( r\, \frac \right) - h_c\, r\, \frac =0. Assigning new variables ''z'' :$z\; =\; r\; \backslash sqrt\; \}$ and ''θ'', where ''T''b is the temperature at the base of the fin, :$\backslash theta\; =\; \backslash frac$ results in the governing equation for heat transfer of an annular fin: :$$ z^2\, \frac + z\, \frac - z^2\, \theta =0. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Annular fin」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.