Applications and Use Cases of CoreFlow™
CoreFlow™ already looks set to find revolutionary applications in the manufacture of heat exchangers, cooling systems, integrated fluid management and the general light-weighting of structures. Heat exchangers can be found everywhere from cars to aeroplanes, but also communication platforms, satellites and ships.
In the electric vehicle (EV) market, for example, there is an increasing need for faster charging rates, improved speed and autonomy, increased power density, and a general ambition to make EVs affordable to the public. These expectations are resulting in increased heat generation and are driving a collective demand for low cost, compact, lightweight and efficient heat transfer solutions.
Battery packs release heat during charging and driving due to electric resistivity. This is aggravated for higher intensity charges and discharges (e.g. fast charging or high loads during operation). Currently, serpentine pipe heat exchangers are incorporated inside the battery pack to prevent excessive temperatures that could lead to cell chemical degradation or battery derating. These systems, however, take up space and add weight and manufacturing complexity to the vehicle, therefore, CoreFlow represents a big opportunity to solve these challenges by manufacturing battery trays with integral cooling channels built into the metallic structure.
Another interesting example is the thermal management of electric motors. These components heat-up mainly due to the resistivity of the copper windings and eddy-current losses, and this excess heat is detrimental to motor performance and may result in permanent physical damage. Cooling systems are usually incorporated into the casing based on natural or forced convection (of air, liquid or both). CoreFlow™ could be used to incorporate channels in thin-walled motor casings for active cooling, reducing overall weight, complexity and improving the performance of the motor.
Aerospace is another industry in which thermal management solutions could be implemented using the CoreFlow™ process. Aircraft engine cooling, for example, is usually performed by heat exchangers located between the engine and the nacelle, cooling the engine oil using air or fuel. These components, however, disrupt the airflow, creating drag and decreasing thrust output. With CoreFlow™ cooling networks could be incorporated directly in the nacelles. The same applies to hydraulic cooling systems, which are usually installed under the wing surface and could be replaced by integrated manifolds manufactured by CoreFlow™, rather than hoses, pipes and fittings.
The channels produced by CoreFlow™, could be used also for anti-icing systems or for embedding instrumentation in metallic surfaces or for reducing the aircraft heat signature.
Currently, FSW is one of the most promising technologies for manufacturing heat exchangers. Their complex geometry currently forces engineers to split production in two stages (see Figure 8). Typically, in the first stage, a housing is casted, extruded or machined from a solid block of metal (usually aluminium or copper) which incorporates cooling features and channels to circulate the cooling fluid through the part. In the second stage, a lid is joined and friction welded in order to isolate the cooling channels from the environment and seal the component. FSW has become the most effective choice to perform the second stage of this manufacturing process.
CoreFlow™ overcame these challenges by machining the cooling channels in the part in a single step. Helical serpentines can be successfully incorporated into aluminium piping or housings to create a thermal management functionality. By creating a channel below the surface of a structure, CoreFlow™ provides an integrated method to vent heat from a part without having to add extra pipework or other complex and costly solutions.
This translates not only to a simpler process, but also to a more efficient and environmental friendly manufacturing method, using approximately 20% less raw material, producing almost 80% less waste (in form of wire), and therefore weighing less than its conventional counterpart (see Figure 8).
Not only will this new technique allow for heat reduction, but can be used for the production of anti-icing features on wings and flight control surfaces for aircraft. The technique can also be used to create lubrication networks for hydraulics, to embed instrumentation into a structure, to perform cable management, or simply for additional light-weighting. Outside of transport, CoreFlow™ can be used for the cooling of data servers, communication infrastructures and radar installations or to manage the thermal load in manufacturing equipment, for example in the semiconductor or display manufacturing industry.
TWI is continuing to develop CoreFlow™ by defining guidelines for use with different workpiece materials, while working on a range of industrially-relevant technology demonstrators.
With a variety of applications having already been proposed for CoreFlow™, this new friction technique could soon be used in industries ranging from aerospace and automotive to electronics and sensors.