HEAT-TRANSFER IN A CHANNEL BETWEEN VERTICAL ELECTRONIC-CIRCUIT BOARDS COOLED BY NATURAL AIR CONVECTION

Heat transfer between vertical electronic boards was studied. Each electronic board consisted of a printed writing plate with 81 or 162 electronic resistance devices attached. Temperature distribution on the writing plate and temperature and gas velocity distributions between the boards were measured with thermocouples and a laser doppler velocimeter (LDV). Those distributions were affected by electric power supplied, distance between the boards and open ratios at the top and bottom of the shelf. The average Nusselt number and average Reynolds number for the electronic boards were obtained. These values were calculated from empirical equations obtained with the flat vertical parallel plates with suitable modification. To calculate the temperature distribution and axial gas velocity distribution between the boards, fundamental equations were solved numerically with suitable boundary conditions. The calculated temperature and axial gas distributions approximately agreed with experimental values.