Heat Sink Fin Orientation

The heat sink should be oriented as in fig 1 or fig 2 under natural convection cooling.

Heat sink fin orientation.

The effect of orientation of this heat sink relative to gravity field will be offset by the fact that about 1 3 of heat flux will be emitted in the form of radiation if the sink is anodized or painted black which will make the surface emissivity to above 0 9. The first plot traveling from the lower left to the upper right is the natural convection curve of heat sink temperature rise tsa versus q. It is recommended that the heat sink be installed to orient the fins in a direction that will not block air movement under natural convection. Air heats and moves up if the fins are horizontal this will be hindered.

Unique fin requirements thermal engineers sometimes need heat sinks with either very tall fins or very thin fins that are tightly spaced. Test results indicate that the sideward horizontal fin orientation yield the lowest heat transfer coefficient. An advantage of bonded fin designs is that the heat sink base and the fins can be of different metals. Light emitting diode led light source is known as the 4th generation illumination technology because.

Typically the fins are oriented in a way to permit a natural convection air draft to flow upward through rectangular u channels or ducts formed by the fins. Experimental setup and analysis method. Thermal resistance will probably increase since it will difficult airflow i e. A trapezoidal fins heat sink with various orientations tested under a controlled environment.

Heat sinks are devices that are used to enhance heat dissipation from hot surfaces to cooler ambient air. Orientation effects on natural convection heat dissipation of rectangular fin heat sinks mounted on leds 1. Heat sink attachment orientation plays a significant role under natural convection. You haven t mentioned if you have forced air flow i e.

However the sideward vertical fin orientation gave the best performance on the natural cooling. Respectively bonded fin heat sinks and skived fin heat sinks suit these requirements nicely. And the radiation is omnidirectional. Wesley lee nov 1 16 at 12 54.