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Abstract Fuel efficiency becomes very important for new vehicles. Therefore, improving the aerodynamics of tires has started to receive increasing interest. While the experimental approaches are time-consuming and costly, numerical methods have been employed to investigate the air flow around tires. Rotating boundary and contact patch are important challenges in the modeling of tire aerodynamics. Therefore, majority of the current modeling approaches are simplified by neglecting the tire deformation and contact patch. In this study, a baseline computational fluid dynamics (CFD) model is created for a tire with contact patch. To generate mesh efficiently, a hybrid mesh, which combines hex elements and polyhedral elements, is used. Then, three modeling approaches (rotating wall, multiple reference frame, and sliding mesh) are compared for the modeling of tire rotation. Additionally, three different tire designs are investigated, including smooth tire, grooved tire, and grooved tire with open rim. The predicted results of the baseline model agree well with the measured data. Additionally, the hybrid mesh shows to be efficient and to generate accurate results. The CFD model tends to overpredict the drag of a rotating tire with contact patch. Sliding mesh approach generated more accurate predictions than the rotating wall and multiple reference frame approaches. For different tire designs, tire with open rim has the highest drag. It is believed that the methodology presented in this study will help in designing new tires with high aerodynamic performance.
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Osprey: A mmWave Approach to TireWear Sensing
Tire wear is a leading cause of automobile accidents globally. Beyond safety, tire wear affects performance and is an important metric that decides tire replacement, one of the biggest maintenance expense of the global trucking industry. We believe that it is important to measure and monitor tire wear in all automobiles. The current approach to measure tire wear is manual and extremely tedious. Embedding sensor electronics in tires to measure tire wear is challenging, given the inhospitable temperature, pressure, and dynamics of the tire. Further, off-tire sensors placed in the well such as laser range-finders are vulnerable to road debris that may settle in tire grooves. This paper presents Osprey, the first on-automobile, mmWave sensing system that can measure accurate tire wear continuously and is robust to road debris. Osprey’s key innovation is to leverage existing, high-volume, automobile mmWave radar, place it in the tire well of automobiles, and observe reflections of the radar’s signal from the tire surface and grooves to measure tire wear, even in the presence of debris. We achieve this through a super-resolution Inverse Synthetic Aperture Radar algorithm that exploits the natural rotation of the tire and improves range resolution to sub-mm. We show how our system can eliminate debris by attaching specialized metallic structures in the grooves that behave as spatial codes and offer a unique signature, when coupled with the rotation of the tire. In addition to tire wear sensing, we demonstrate the ability to detect and locate unsafe, metallic foreign objects such as nails lodged in the tire. We evaluate Osprey on commercial tires mounted on a mechanical, tire-rotation rig and a passenger car.We test Osprey at different speeds, in the presence of different types of debris, different levels of debris, on different terrains, and different levels of automobile vibration. We achieve a median absolute tire wear error of 0.68 mm across all our experiments. Osprey also locates foreign objects lodged in the tire with an error of 1.7 cm and detects metallic foreign objects with an accuracy of 92%.
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- Award ID(s):
- 1823235
- PAR ID:
- 10195728
- Date Published:
- Journal Name:
- The 18th ACM International Conference on Mobile Systems, Applications, and Services
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/https://doi.org/10.1145/3386901.3389031
