| Abstract [eng] |
This final master's degree project analyzes the impact of tire pressure changes on rolling resistance in passenger cars. The relevance of this topic and the research being conducted stems from the growing importance of sustainability in everyday life and ecological contexts. The overall goal of the work is to determine how tire pressure in passenger cars depends on the distance covered during the trip and on the resulting changes in rolling resistance. To obtain the results of the work, dynamic and several static studies of different methods were conducted. Using dynamic tire pressure and temperature measurements under real operating conditions, the aim was to determine trends in pressure and temperature changes during vehicle operation. The static studies of the tire contact area were carried out to determine the influence of pressure on the contact surface of the tire with the road surface. The study also accounted for potential additional vehicle loads and their impact on the results. To improve the accuracy of the results, studies whose exact values were difficult to determine were repeated several times, yielding average values for the final assessment. However, static tire footprint studies, using tracing paper for recording, were performed one test at a time. Since the results were clearly recorded, the values were easy to evaluate. A dynamic study of tire pressure and temperature showed that these parameters vary under real operating conditions. The values of their change are slightly correlated. The study on the influence of static tire pressure on the contact patch area showed that as vehicle tire pressure decreases, tire deformation increases, resulting in a noticeable increase in the tire footprint area. An increased contact surface area results in a higher rolling resistance coefficient, which decreases vehicle efficiency. The opposite trend was observed during testing when tire pressure was increased beyond the manufacturer's recommended values. The contact surface area decreased, thereby reducing the tire's rolling resistance coefficient. In terms of efficiency, such a result could be viewed as positive, but operating tires with excessive pressure is still considered unsustainable and unsafe behavior. Static tire pressure tests also investigated the effect of additional load on tires. During the test, it was found that additional load can affect tire operation, as adding it to tires intended for the winter season clearly increased the contact surface area. Thus, after studying tire pressure and temperature changes, it can be concluded that tire pressure varies both when the car is stationary and during operation, and these changes can have various effects. As a result, it is recommended that drivers check tire pressure before planning long car trips, thereby reducing the likelihood of driving long distances on overinflated tires. |
