High Heat Flux Testing

A major problem with testing devices for high heat flux cooling, is generation of heat fluxes in the range of 500-2000 W/cm², that can be controlled accurately.

CapeSym has developed a turnkey system capable of applying upto 2kW in a target of arbitrary size and shape. This device can accommodate liquid as well as gas coolants, and is fully integrated with data acquisition and control/measurement software. Thus,heat flux at the target surface, target surface temperature, flow rate, pressure drop and temperature rise of the coolant can be displayed in real time and logged.

The hardware is built around a copper block with embedded heaters is used as the heat source. The cooling device is placed on the top surface of a copper post which is attached to the top of the heater block. Two thermocouples in the narrow region of the post are used to calculate the heat flux through the post, and thereby heat flux at the target surface. The T/C readings are also used to calculate the temperature of the target/cold plate interface. The top surface of the post can be machined to any arbitrary size and shape. The high thermal conductivity of the copper ensures that the heat flux across the target surface is uniform.

The entire test assembly is contained within a vacuum chamber to eliminate heat leak by natural convection and to avoid oxidation of the copper surfaces.


High heat flux setup with the MJCA housing bolted to the heater block.	Aerial view of the heater block and MJCA housing inside the vacuum chamber.	The post connects the target surface to the heat source. The target surface can have an arbitrary shape and size.