Passive Cooling of Heat Generating Cylinders in Parallel Channels

The objective of this paper is to study cooling by induced convection of vertical cylinders in parallel channels. The system has four vertical channels of circular cross-section, connected to shared entrance and exit horizontal ducts. One to three heat-generating cylinders are mounted inside each channel. The cylinder is 50mm in diameter and 100 mm high. It is heated from inside by a cartridge heater, installed in a drill along the cylinder axis and connected to an external power source. The study aims at finding the preferable configuration in which the maximum and mean temperature of the cylinders would be the lowest. Among the factors explored, there are various channel diameters, non-equal number of cylinders in the channels, different power inputs to the cylinders, and different entrance-exit configurations of the ducts. A laboratory-scale model is studied both experimentally and numerically. Temperature measurements are performed at various locations by fine thermocouples using a multi-channel data acquisition unit. Numerical simulations are performed for the velocity and temperature fields in the system, using the Fluent 6.0 software, accounting for both convection and radiation. The cylinders are modeled as they were built in reality: they have a heat-generating core and conducting body. Comparison of the experimental results with the numerical predictions is presented and discussed.