Effective Cooling of Circuit Elements at High Temperature in Military Equipment

Today, rapid development in technology also accelerates development in all sectors. Military field is also adopting and applying these technological developments. In addition to these technological developments, increased competition in military field between countries causes system developed for military purposes to advance and become more complex. Various military systems and weapons contain electronic equipment. This equipment can reach high temperatures during operation. In this case, if this equipment is not cooled to a secure operating temperature, electronic circuit elements in this equipment may burn, and this situation disables operation in all military system. In case of an emergency, to disable military system, these heated circuit elements should be cooled in a fast and effective way and also these elements should be kept in safe operating temperatures. Therefore, in this study, effective cooling for electronic circuit elements inside a military system is analysed. A block shaped object that represents circuit elements inserted inside a channel volume that represents the volume of the motherboard of a military system is considered. It is assumed that this block with high temperatures is effectively cooled with cross-flow and jet flow together. For this purpose, air input to channel input is supplied with constant velocity and cross-flow conditions are met. By providing air input with constant velocity from a hole on the upper surface of the channel, impinging jet flow conditions met. Analysis are conducted for calculated Reynolds number 500, 1000, 1500, and 2000 values based on cross-flow air input conditions in laminar way. For these Reynolds numbers, ratio of jet input air velocity to cross-flow air velocity (Vj/Uk) rechanged and simulations are repeated for each value. As a result, it is determined that with increased Reynolds number and Vj/Uk value, heat transfer on block surface increased as well