Heat Exchanger World magazine April 2024 | Page 39

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Additive Manufacturing
Examples of dissimilar metal combinations with UAM .
The second advantage of UAM is that it enables the embedding of sensors and other measurement devices into metal parts . Devices such as fiber optic cables , thermocouples , strain gauges , and other sensors can be fully embedded into the metal matrix for improved measurements , protection of sensors from the outside environment , and closer measurements to the area of interest . This allows for engineers to include various sensors into their heat exchanger , or cold plate , designs , enabling the collection of real-time , in-situ data for better understanding performance , refining digital twin models , and collecting health-monitoring information of their system . The third main benefit of UAM is that it allows for complex internal channels for flow devices and heat exchangers . While most additive methods include this benefit , the advantage of UAM is that all of these complex channels feature a CNC machined surface finish . In fact , UAM produced parts do not require any post-printing surface finishing , heat treating , or HIPing . UAM machines are CNC machines retrofitted with the UAM technology which allows for seamless alternating between additive and subtractive manufacturing processes . In order to create complex internal channels in a part , the channels are simply machined with the subtractive portion of the machine and then capped with the additive portion of the system using UAM . Furthermore , this hybrid process allows for in-process inspection of parts , whereas additive processes such as LPBF do not .
NASA utilizes UAM for improved heat exchanger efficiency In many aerospace applications , heat piping is adhered to a surface using epoxy or brazing in order to heat or cool a particular area , device , or component . While epoxying and brazing are somewhat viable options for heat transferring devices , these techniques can lead to points of failure and loss of efficiency in the system . NASA came to Fabrisonic looking for a replacement for the aforementioned processes , and UAM was the perfect fit . Fabrisonic , in conjunction with Utah State University , manufactured a heat exchange panel that greatly improved the performance of the overall system . Instead of bending tubing and adhering it to a panel , UAM can seamlessly integrate the channels into the panel . By manufacturing the channels into the part as one , there is no joint between the fluid pathways and the outside panel face . This improves the overall efficiency of the device while removing a potential point of failure in the system . Another critical aspect of aerospace parts is the weight of each component in the system . Even a pound of material can lead to a huge increase in cost and a decrease in flight efficiency . Knowing this , Fabrisonic was able to reduce the overall weight of the panels while increasing the efficiency of the heat exchanger by removing some of the panel thickness and replacing it with ~ 0.010 ” of copper material . Copper is more than twice as conductive as aluminum , resulting in a huge gain in overall thermal efficiency . Also ,
Finned internal channels on a heat exchanger . NASA bi-metallic heat exchanger panel . www . heat-exchanger-world . com Heat Exchanger World April 2024
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