“From a theoretical perspective, NLR has a long history in advanced modelling and has contributed to a variety of different projects spanning the military, private and public domains,” explains Jesper Lansink Rotgerink, R&D Engineer at NLR. Simultaneously to working as an engineer at NLR, Lansink Rotgerink is a PhD candidate from the University of Twente, who has spent part of his time at NLR working on his PhD project focused on understanding and modelling EMC of aircraft and spacecraft, with a specific focus on crosstalk between cables.
“When you put new equipment onboard of an aircraft, you must ensure that it won’t disturb legacy equipment already deployed in an unforeseen manner,” says Lansink Rotgerink. As part of his PhD project, Lansink Rotgerink decided to delve into the EMC phenomena of crosstalk, or interference, between cables. Particularly as aircraft and spacecraft start to adopt more and more carbon-fibre reinforced plastics, which is much less conductive compared to traditional metal and aluminium structures, Lansink Rotgerink was interested in seeing what effects that had on signals and crosstalk.
“When we got started on the experimental side, we noticed some really interesting differences that we couldn’t explain, when comparing low-frequency and high-frequency signals while using the non-conductive ground plane. That’s when I started getting into modelling different ground planes to understand the theory behind the behaviour,” illustrates Lansink Rotgerink. “Using well-known models for cables and ground planes as a start, I adapted them to also capture the effects of less conducting, composite ground planes. With these tweaks in the models, we see that the simulated data is a match with the measurements we performed in the EMC facility in the experimental phase. Using this advanced modelling of the system, we now have reliable data sets and understand underlying physical behaviour. We can use this to predict how these widely used cables affect aircraft and spacecraft with composite parts.
Mission-based environmental testing for space
It’s exactly this level of both practical experience and theoretical expertise that has attracted numerous partners and companies to work with NLR. But this isn’t the only way the aerospace specialist aims to provide support to the domain. It also takes an active role in collaboration and leadership on several national and international projects aimed at moving the industry forward, specifically with an eye toward the ever-growing space market. “Recently, we participated in a project for the European Space Agency (ESA) where we collaborated with the University of Nottingham to completely design a software tool used to predict interfering behaviors, such as crosstalk, geared specifically for the space domain,” claims Lansink Rotgerink. “In the aviation sector, customers know what value we can add, particularly in validating technologies. But this platform of experience in practice and theory also meshes strongly with the space industry. Whether it’s developing our own tools, or applying those already developed, NLR offers a level of understanding that other institutions can’t quite match.” This of course, can be a little tricky in the space domain because the stringent standards of aviation and even automotive aren’t as clear cut. Qualification in space is more mission-based and depends on the objectives, meaning it’s much less standard in nature.