The noise made by car tires is a nuisance to people within the car and outside of it. Apollo Tyres Global R&D in Enschede, the Netherlands, enlisted PDEng trainee Martin Goossens for a project to design quieter tires. Martin recently completed the PDEng program Energy & Process Technology at the University of Twente (UT).
Interior noise is caused by sound waves that arise from the contact between road and tire, are amplified in the hollow space within the tire and are transferred to chassis and bodywork by the rims. Apollo, aiming to combat this noise, went looking for someone with the right experience to take on this project. PDEng trainee Martin Goossens from the University of Twente was the ideal candidate: his master’s thesis in mechanical engineering was on a quieter design for wind turbine blades. Since Martin - like all PDEng trainees - already had a master’s degree, he was able to work on this complex design project with a high degree of independence. The University of Twente supported him where needed. During his PDEng program, Martin took a variety of courses at the university, which allowed Apollo to benefit directly from the latest scientific developments.
Ideas, prototypes and testing
Martin quickly started suggesting design ideas for quieter tires, made prototypes and did tests. In a Spanish testing facility, he did measurements in a ‘silent’, semi-anechoic space (a space without engine and wind noise). With help from the UT Fluid Mechanics research group, Goossens designed and built his own testing setup. One of his in-depth electives was Engineering Acoustics, and his standard courses included Design Methodology and System Engineering. Martin: “This really taught me the fundamental principles of design, which I could immediately apply at Apollo. For instance, I learned that it is important to set goals early, such as the amount of noise reduction and the allowances for increase in rolling resistance and maximum additional weight. During the design stage, you can then continuously monitor whether you are meeting your requirements.” Apollo started a project team, led by a project manager, where Goossens worked with someone from purchasing and process, patent and test engineers. “That way, you can also look at things like manufacturability and safety requirements.”
Many decibels of noise reduction
Working with Martin resulted in two comprehensive designs: one proven acoustic technology for quick results and an innovative solution requiring more development. Goossens: “Tests in Belgium showed a noise reduction of many decibels. That resulted in a patent filing.” Since that time, Goossens has accepted a job as development engineer at Apollo. “In this position, I will continue where my PDEng project left off, to take a broader look at tire characteristics. For instance, in addition to noise reduction, I am also looking at improving rolling resistance with innovative ideas.' A perfect result for Apollo: good results and a new, enthusiastic employee who is already highly familiar with the company.