Thermal Design and Analysis of Electronic Enclosure of Ground Radar

Abstract

When an electronic component is powered heat will be developed which will in turn increases the component temperature. For safe functioning of these components manufacturer specifies allowable temperature. If the component temperature exceeds these limits component fails. To get rid of this situation heat dissipation mechanism must be effective. Thermal design of an enclosure for PCBs of a ground RADAR is taken up in this work. The primary objective is to enhance the heat dissipation rate with the proposed enclosure in forced convection environment. Selection of fan and estimation of cooling rate is also be done. The complexity associated with this requirement is to estimate the heat transfer coefficient for the proposed enclosure in forced convection environment. This is due to the reason that the standard literature limits its scope to presentation of empirical correlations for heat transfer coefficients for standard geometries like plate, pipe, etc. Where as in the current requirement heat transfer coefficient is to be estimated for the enclosure with complex geometry. As part of the work an analytical method is established to estimate the heat transfer coefficient and the same is validated with commercial CFD software package. After validation process maximum component temperature is calculated in order to ascertain the cooling effectiveness of the proposed thermal design by ensuring that maximum temperature is within the prescribed limits. Apart from meeting the primary objective i.e. providing suitable heat dissipation mechanism and ensuring component temperature within limits another intended outcome of the work is an analytical method to calculate heat transfer coefficient for electronic enclosures quickly without depending on commercial CFD software.