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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

COMPUTER ANALYSIS OF HEAT TRANSFER PROBLEMS TO CHECK THE VALIDITY OF ENGINEERING FORMUIAE

Get access (open in a dialog) DOI: 10.1615/IHTC8.3450
pages 325-330

Résumé

Nowadays, many heat transfer problems can be easily analysed numerically by using various advanced software programs. However, simple formulae which approximate the computer results are often a better solution for engineering purposes. The object of the study is to provide engineers with such formulae for two problems in the field of heat transfer. In order to check the validity a computer package is used for simulation at a detailed level.
The problems discussed are:
1. Joule heating in electrolytic capacitors caused by ripple currents. Simulation shows that the formulae normally used for the calculation of the maximum allowable ripple current are incorrect. A simple correction factor appears to be sufficient to accommodate for the effects of the normally neglected heat flows.
2. Heat sink dissipation. A computer model has been made of a flat heat sink for power devices. The influence of several parameters on its thermal resistance is demonstrated. An easy-to-use formula is derived for the case of a centrally located power source.