Impact on liquid-to-air cooling duct design
There are two types of turbocharge systems: supercharger and turbocharger. Air-to-air cooling (direct) or liquid-to-air cooling (indirect) can be used for turbocharged systems. Liquid-to-air cooling is the latest development to integrate the charge air cooler (CAC) into the air intake manifold (AIM), using liquid instead of air to effectively cool the air.
Integrating the CAC into the AIM reduces the length of pipe previously needed to reach the air-to-air cooler in the front of the vehicle, leading to an increase in engine responsiveness. It also increases the temperature in the AIM (currently up to 230°C) and the mechanical requirements for the materials used. This enables auto makers to deliver higher performing engines while meeting emission limits.
In cases where package space, design, or cost prevent the ability to integrate the CAC into the AIM, liquid-to-air cooling can still be implemented by mounting the CAC directly onto the engine, as a standalone component and near the AIM.
Moving from air-to-air cooling to liquid-to-air cooling will impact geometry and part requirements for ducts, by whom/when the ducts are designed and in what fashion the ducts are secured to mating components. Manufacturers will want to work with materials that enable weight reduction via metal and rubber replacement, increase engine efficiency, reduce emissions and noise, plus increase safety while decreasing system cost.
There is a technology specifically invented for elevated continuous-use temperatures of 180-230°C—a material that offers long-term heat ageing performance at elevated temperatures, higher peak temperature and performance and better chemical resistance. Diablo technology, invented and patented by DSM, improves the long-term temperature resistance of materials, such as Akulon PA66.
The new Akulon Diablo materials—Akulon Diablo HDT2505 BM and Akulon Diablo HDT2504 BM—offer best-in-class heat aging performance that covers a wide temperature spectrum and impressive strength that enables thinner wall and part mass reduction, along with a robust processability to help ensure a low scrap operation. Both grades leverage exclusive DSM technology to maintain tensile strength despite rigorous heat-aging tests exceeding 200◦C for 3,000 hours. Since the unique formulation allows the material to retain its original strength over time, this allows for thinner walled part design, which can reduce total system mass by up to 40%.
Respecting that engineers expect robust property retention over a wide range of operating conditions, the new Akulon Diablo materials have been designed to deliver robust heat aging performance both at the extreme temperature of 220°C as well as the more moderate temperature of 150°C and all temperatures in between. This helps to ensure that the product performs over a wide range of performance conditions in order to cover a broad array of application needs.