SET Proceedings 2978-4387 Caravel Press 10.65582/set.2004.002 2004.002 A Second Degree Approximation for the Calculation of the Transfer Function Coefficients for Heat Flux Through Walls Chávez ChenaY. laxyc4@nottingham.ac.uk WilsonR. MedjdoubB. Lira CortésL. School of Built Environment, University of Nottingham, University Campus, Nottingham NG9 2RD, United Kingdom School of Built Environment, University of Nottingham, Nottingham, UK Centro Nacional de Metrología, CENAM, Querétaro, México 28062004 3 978-1-995850-06-1 1 6 28 June 2004 © 2004 Copyright WSSET 2004

Calculation of the conduction Transfer Function Coefficients using a state space representation requires the transient governing differential equation to be discretized in space by the use of finite difference or finite element methods in order to obtain a set of first order differential equations. In this paper the one-dimensional heat flow problem is tackled using a new quadratic element for use with the finite element method. The variational formulation for the governing differential equation is developed, the Ritz Approximation to construct the finite element formulation is used and the approximation functions are presented using a normalized local coordinate system for elements with three equally spaced nodes. Results with 1, 2 and 5 three-node elements are compared with those obtained by the use of finite differences with 2, 5 and 20 nodes and shown to be in good agreement.

 transfer function coefficients heat transfer finite element 28 to 30 June 2004 3rd International Conference on Sustainable Energy Technologies SET2004 3 Nottingham, United Kingdom