A heatsink comprising a heat exchange device having a plurality of heat exchange elements each having a surface boundary with respect to a heat transfer fluid, having successive elements or regions varying according to a fractal relationship. According to one embodiment, a noise spectrum due to fluid flow is wideband. According to another embodiment, surface boundary layers are disrupted to increase heat transfer. Flow-induced vortices may be generated at non-corresponding locations of the plurality of fractally varying heat exchange elements.