Abstract: An active heat sink is described for use in the transfer of heat from a heat generating device such as a semiconductor chip and the like with a heat sink having an embedded fan surrounded by a plurality of heat conducting flow augmenting rings separated by apertures through which a radially inward flow arises and with the rings being sufficiently axially separated to enable fan propeller tip vortices to penetrate the axial spacings so as to cause a substantial cooling of annular ring regions so as to raise the overall heat transfer coefficient of the active heat sink in a significant manner. Several embodiments are described.

Abstract: An active heat sink is described for use in the transfer of heat from a heat generating device such as a semiconductor chip and the like with a heat sink having an embedded fan surrounded by a plurality of heat conducting flow augmenting rings separated by apertures through which a radially inward flow arises and with the rings being sufficiently axially separated to enable fan propeller tip vortices to penetrate the axial spacings so as to cause a substantial cooling of annular ring regions so as to raise the overall heat transfer coefficient of the active heat sink in a significant manner. Several embodiments are described.

Abstract: Improvements to a propulsion thrust apparatus are described wherein a propeller is surrounded by a ring cage structure with which propeller tip vortices are converted to useful mass flow with a plurality of rings whose spacing from each other and the propeller are selected so that in one embodiment at least one ring is placed inside an enclosure and the others are outside. The operation of the propeller then produces an enhanced circulation of the air inside the enclosure without hot spots. In another embodiment, the rings are segmented to provide additional vortices for enhancement of the propeller mass flow. With another embodiment, at last one of the rings are provided with discontinuities on the inside edge to promote the generation of vortices that improve mixing of tip vortices and provide a noise reduction effect.