Solving Complex Heat Transfer Problems with Additive Manufacturing and Advanced Design

Engineers face increasingly complex product requirements, making the need for thermal management tools and solutions paramount. Additive manufacturing and the right engineering design software can allow you to design the next generation of innovative heat exchangers to meet these demands.

Product designs are becoming increasingly complex. They are more powerful, electrified and digitally connected, which means the heat generated by their transmission, power and electronic subsystems increases. Despite this, the space available to handle this heat generally remains the same.

This trend requires new generation heat exchangers, which are more compact and efficient, and additive manufacturing enables engineers working in various industries to achieve this goal. But to make these superior heat exchangers a reality, you must combine the latest thermal management design techniques with advanced engineering design software.

This article will explore how you can use additive manufacturing and nTopology’s advanced design software to solve increasingly complex heat transfer problems.

Thermal management and heat exchangers

heat management is an engineering application that helps you maintain proper temperatures inside products and processes, dramatically improving product reliability, lifespan, and performance.

Thermal management requires that the heat generated by the various components and subsystems of a product is properly managed. There are many techniques for managing heat transfer, but at the heart of every thermal management system is a heat exchanger.

Heat exchangers move thermal energy from hot regions to cold regions. There are many types of heat exchangers, including radiators, cold plates, heat sinks, and oil coolers. You are likely to find high performance heat exchangers in aircraft and road vehicles, electronic cooling, and precision manufacturing.

The Need for Thermal Management Solutions Across All Industries

Organizations in many industries need better thermal management solutions to enable them to create more complex, innovative and reliable products. Here are some examples of applications where improved thermal management is essential.

Autonomous vehicles

Control electronics are a critical safety factor in autonomous vehicles, which are susceptible to become the norm in the near future. The processing power required to operate an autonomous vehicle is significant and increases rapidly as the calculations become more complex. This helps generate more heat, which can lead to thermal instability if not managed properly. Advanced thermal management has a vital role to play in creating innovative autonomous vehicles.

Electrification

The demand for electric vehicles in the automotive and aerospace industries is growing rapidly. But these complex systems include batteries and power electronics that can produce a significant amount of heat and require highly efficient cooling mechanisms. Ensuring these components are operating at optimum temperatures is critical to maintaining product integrity and can ultimately improve vehicle performance, life and fuel economy.

Modernization

Modernization and upgrading can breathe new life into old assets that were not designed to meet modern performance demands. The introduction of obsolete equipment in the modern world has added stress to thermal systems. Heat transfer should be a primary design consideration when attempting to maximize the value of these older assets.

Manufacturing

Many companies are setting up new manufacturing facilities in Europe and the United States, driven by supply chain disruptions in recent years. Businesses need to operate more efficiently to account for the increased cost of setting up these facilities. Thermal management can often be a barrier to achieving this. For example, in injection molding and thermoforming, heat flow can affect both product quality and throughput.

Additive manufacturing for thermal management

Traditional manufacturing processes and traditional design software often limit your design freedom. These limitations may affect your ability to create innovative and highly efficient heat exchanger designs for the next generation of products.

By providing greater design freedom, additive manufacturing can help you create new heat exchanger designs that meet increasingly complex product requirements.

Heat exchanger design

When optimizing a heat exchanger design, there are generally three main design goals to consider:

● Maximize heat transfer

● Minimize pressure drop

● Reduce size

By combining additive manufacturing with the use of advanced engineering design software, you can balance these often conflicting design goals and create heat exchangers that are more compact and perform better.

Additive manufacturing and advanced engineering design software have opened the door to new possibilities for heat exchangers. You can create smooth transitions for heat exchanger inlets and outlets, develop an outer casing of varying thickness, generate flow and thermal guides, and more. One area of ​​opportunity for improvement in heat exchanger design is the core.

The core of the network


The core of a heat exchanger is usually filled with a lattice structure. A lattice structure is a repeating pattern that fills the volume or conforms to the surface of a heat exchanger. These lattice structures consist of beams, surfaces or plates connected together in a particular pattern.

In the case of liquid-liquid heat exchangers, lattice structures with triple periodic minimum surface (TPMS), such as gyroid or diamond, generally give the best results. For solid-liquid or solid-air heat exchangers, bundle-based networks are generally more viable than TPMS.

Let’s focus on the TPMS cores. These lattice structures offer many advantages in the design of heat exchangers. The large surface area of ​​a TPMS core is ideal for heat transfer while ensuring that you can fit the heat exchanger into the available design space.

Gyroid network structures naturally separate the flow into several intertwined channels or domains and can smoothly guide the flow when manipulated or distorted. Additionally, TPMS cores are self-supporting and easy to fabricate, making them ideal for designing high-performance heat exchangers.

While it’s possible to manufacture basic trusses using traditional processes, such as welding or casting, additive manufacturing allows you to create more complex structures at a lower cost. And with the right engineering design software, you can maximize the benefits of using additive manufacturing to create these complex lattice structures.

A real world app

Seeing real-life examples of using this technology can give you ideas on how you can improve your heat exchanger design.

Cold plate for automotive electronics

Power electronics are essential to the operation of any electric vehicle. In a high-speed racing environment, members of the Dynamis PRC Electric Race Car Team push their vehicles to the absolute limits. Working with Puntozero, Dynamis set out to reduce the weight and improve the cooling system of its high voltage traction inverter.

This essential component converts direct current into alternating current to power the motors of electric vehicles. Liquid cooling systems for high voltage traction inverters maintain temperature within the operating range but are heavy and bulky. The cooling system contains a cold plate heat sink, which was the main focus of the project.

The team identified uneven flow near the curved channels in the conduit. Additionally, the team found that the heat transfer surface of the cold plate was not large enough for the application. After several design iterations, the team developed a final cold plate with flow guides, an external lattice structure, and a modular design.

The flow guides were based on a gyroid array structure created using field-driven design techniques. Puntozero engineers used basic mathematical equations to create a two-body field describing the conduit channel. The engineering team then warped the gyroid array along the X and Y directions to guide the flow around the bends. Flux guides have increased the heat transfer area by 300%. Another advantage was that turbulent flow was eliminated around the curved channels.

Puntozero engineers decided to use a diamond TPMS lattice structure for the main cold plate structure. The external network reduced the component’s weight and production cost, improved manufacturability, and increased the contact area with the power electronics to promote heat transfer. This lattice structure reduced the overall weight of the system by 25%.

The team relied on nTopology, a unique advanced engineering design software, to achieve these goals.

Design software for thermal management

nTopology is next-generation design software built from the ground up to let you take full advantage of the design freedom associated with additive manufacturing.

nTopology’s core technologies make it fundamentally different from any other engineering design software on the market today. With its unbreakable implicit modeling engine, field-driven design capabilities, and reusable workflows, nTopology enables engineers to solve even the most complex thermal management problems.

Want to learn more about thermal management? Download nTopology’s Complete Thermal Management Guide here.

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