71 results about "Thermal signature" patented technology

A system for cooling a structure or mechanism through transpiration processes. Generally a porous structural material may be used to form a hot wall surface of a high temperature or high heat flux environment component, typically used in combustion type devices. Coolant pressurized on the “cold” or cooler side of the wall is bled, “sweated”, or otherwise transpired to the “hot” wall surface in an effort to control the hot wall surface temperature by shielding the surface with a coolant layer at the surface and by removing heat via coolant flow past the surface. This may be done to manage the hot wall temperature for structural purposes, more effectively manage high heat fluxes, or to hide thermal signatures. The porous material can be selectively made such that the coolant material flows substantially in one direction only through the porous material to transfer thermal energy only away from the structure rather than towards the structure.

A system and method for masking a hardware boot sequence are provided. With the system and method, one of the processors of a multiprocessor system is chosen to be a boot processor. The other processors of the multiprocessor system execute masking code that generates electromagnetic and / or thermal signatures that mask the electromagnetic and / or thermal signatures of the actual boot processor. Such masking may involve running the same boot code as the boot processor but without obtaining access to security information, such as the security key for accessing the system. The electromagnetic and / or thermal signatures generated by the execution of the masking code preferably approximate the electromagnetic and / or thermal signatures of the actual boot code executing on the boot processor. In this way, it is difficult to distinguish which processor is the actual boot processor.

A watercraft with a propulsion engine includes at least one hull having an underside. A dual exhaust system includes a first exhaust conduit defining a first exhaust flow path leading to the underside (e.g., a step in a planing surface on the underside) and a second exhaust conduit defining a second exhaust flow path to atmosphere. One embodiment is self proportioning. In another embodiment, an onboard proportioning system varies first and second proportions of the exhaust flowing through respective ones of the first and second exhaust conduits according to exhaust back pressure. First and second valve mechanisms selectively restrict the first and second exhaust flow paths under computer or manual control according to pressure sensed by a back-pressure-sensing component in order to thereby direct the exhaust in desired proportions for enhanced operating characteristics and reduced thermal signature.