Conflux Technology, a Geelong-based additive manufacturing (AM) applications company, has patented a highly efficient, compact heat exchanger design that derives its performance from a geometry that can only be made using AM.

High surface area density, combined with optimised fluid pathways and 3D surface features, results in a high thermal exchange, low-weight, low pressure-drop heat exchanger. The performance advantages were achieved within a rapid development timeline that was underpinned by computational fluid dynamics (CFD) modeling and Design for AM expertise. With no tooling implications to consider, multiple variants can be manufactured simultaneously.

Heat transfer is a ubiquitous challenge that is at the heart of the First Law of Thermodynamics. A heat exchanger, simply speaking, is a device that effectively transfers heat between two or more fluids, typically liquid-liquid, liquid-gas, gas-gas or multiple fluids. You can find them in products like air conditioners and car engines. One practical benefit of such devices is energy recovery. There are numerous others — it is a complex technology with broad applications. Heat exchanger designs and manufacturing methods have evolved with the prevailing technologies available and, consequently, have been limited by those technologies.

Conflux’s Founder and CEO, Michael Fuller, spent more than a decade as an engineer in the automotive racing industry. Here, heat exchangers have to perform in harsh environments, meaning that smaller, more efficient components are constantly sought, but substractive manufacturig methods had reached their limits.

Fuller saw the rapid, transfomative benefits of 3D printing and ultimately identified AM as an enabling technology for the next generation of heat exchangers. Highly complex geometries with hitherto unachievable surface area densities could be achieved, resulting in a compelling thermal exchange performance, all packaged in efficient volumes.

Such components could have a dramatic effect on future developments, such as lighter racing cars and aircrafts. These fundamental opportunities are extended when functions are integrated and multi-variant simultaneous production is realised. Fuller set out to take this idea from concept to design to prototype to product, using industrial 3D printing.

Conflux analysed the industrial AM landscape and, after a technical due diligence process, concluded that EOS was the only partner with the technical and commercial capabilities to fulfill its ambitions. The Conflux Core design was patented after a rapid proof-of-concept development program. Within just six months, six prototypes were built and a final product could be developed.

During the development program, several tools were utilised: CFD complemented the heat exchanger design iterations with flow visualisation and, after correlation, performance predictions. Non-linear thermomechanical finite element modeling was used to analyse the resultant displacements and stresses to ensure structural integrity was maintained.

EOS equipment possesses a suite of specific AM software tools for data preparation, process optimisation and quality assurance. These were all used during the development of the Conflux Core heat exchanger, which now has applications across multiple industries such as aerospace, automotive, oil & gas, chemical processing and micro-processor cooling.

The Conflux Core heat exchanger was compared to a Formula 1 benchmark. Young Calibrations, a UKAS-certified laboratory in the UK, provided accredited calibration services and thermal fluid and component testing services, and tested Conflux’s product. The results underlined the radical improvement Conflux has achieved with its 3D-printed heat exchanger.

AM allowed Conflux to design internal geometries that radically increased the surface area in a given volume. This tripled the thermal heat rejection. At the same time, the pressure drop is reduced by two-thirds. Additionally, AM enabled a compact new design for the heat exchanger, reducing its length by 55mm compared with a F1 benchmark. This ultimately also eliminated 22% of the weight. The design flexibility AM offers allows for optimum placement inside a vehicle and also enables the merging of components, reducing the overall number of parts. Integration of subcomponents into a single part removes assembly time and reduces failure points from joints and seams.

The Conflux Core heat exchanger is the foundation upon which Conflux has developed into an AM applications company focused on thermal and fluid challenges. Customers and development partners from diverse markets have provided Conflux with equally diverse challenges. With an R&D pipeline driving expansion of intellectual property, the company’s technological success stems from its in-house expertise in Design for AM, computational modeling and a deep engagement with EOS. Conflux can work with customers and development partners to create compelling thermal and fluid solutions that will assist in realising the potential of AM within their enterprise.

“Our customers have acceptance criteria that matches exacting quality and repeatable performance,” says Fuller. “EOS systems are the only AM platforms that can produce our challenging geometries whilst exceeding our customers’ requirements.”