Chapter two
Steady-State Conduction - One Dimension
Introduction:- In this chapter an attempt will be made to derive general heat conduction equation and examine the applications of Fourier s law of heat conduction to the calculation of heat flow in some simple one-dimensional systems.
General Heat Conduction Equation :- In the last section we considered one-dimensional heat conduction and assumed heat conduction in other directions to be negligible. We will develop the governing differential equation in such systems in rectangular, cylindrical, and spherical coordinate systems.
Cartesian Coordinates: Consider a small rectangular element of length (?x), width (?y), and height (?z), as shown in Figure. Assume the density of the body is and the specific heat is C. An energy balance on this element during a small time interval )t )can be expressed as.
This is the one-dimensional heat-conduction equation. To treat more than one-dimensional heat flow, we need consider only the heat conducted in and out of a unit volume in all three coordinate directions, as shown in Figure. The energy balance yields.
المادة المعروضة اعلاه هي مدخل الى المحاضرة المرفوعة بواسطة استاذ(ة) المادة . وقد تبدو لك غير متكاملة . حيث يضع استاذ المادة في بعض الاحيان فقط الجزء الاول من المحاضرة من اجل الاطلاع على ما ستقوم بتحميله لاحقا . في نظام التعليم الالكتروني نوفر هذه الخدمة لكي نبقيك على اطلاع حول محتوى الملف الذي ستقوم بتحميله .
|