Studie nového způsobu chlazení brzd závodního automobilu

Abstract

The proposed concept of active brake cooling in racing cars called G -Cooling System (GCS) is designated for the Formula One racing cars. The cooling system is based on the assumptions of operation at high speeds. Whether it is possible to deal with the brake cooling system using GCS in passenger or goods vehicles, it is an issue; however, it cannot certainly be ruled out. The main idea of G- Cooling System is in its dual cooling. Thanks to the IT4Innovations project, it was possible to perform mathematical simulations of flow solving the prediction of the turbulent events of the newly proposed cooling system. Based on these findings, the prototype has been produced. The measurement of the brake disc temperature behaviour on a dynamometer was one of the key experiments. A carbon-carbon brake disc was equipped with one thermocouple as well as the brake calliper. The temperature of the discs was about 10% lower and the cooling time was reduced by approximately 18%. Throughout the test, GCS showed more stable temperature behaviour than a traditional braking system. It has been observed that the cooling ability of the GCS, increasing air flow into the centre of the disc, increasing its cooling exponentially. The calliper is able to cool itself almost 20% more than its colleague with conventional solutions. During the measurement, there was no occurrence of any vibration or undesired wear of the components. The GCS system also has not shown the capture of particles in inaccessible areas of the system, therefore it can be said that it has so called self-cleaning effect. Comparison of real experiment and computer simulation turned out inside the dynamometer in accordance with the assumption of the author. Result of the measured values on the brake disc have not correspond with the course subtracted results from the simulation. The main reason for all these differences is in the wrong setting initial values in the calculation. For more accurate outputs from the simulations would need more position measurements on the real assembly or let the simulation run in several cycles braking, which would be very time consuming. However, although the maximum difference between reality and numerical calculation was about 50°C, so the next step will be similarly set a simulation of the brake discs (GCS) in dynamometer. When selecting the same boundary conditions, the results of both simulations will only refers to the relative difference values and the sensitivity to a change of geometry, which ultimately determines the relative efficacy between the two brake systems. The first real experiment was carried out on BMW Alpina B6 racing car at SlovakiaRing racing circuit in the Slovak Republic. The steel brake disc was drilled having a total of six hundred holes and fitted with an aluminium diffuser. During the testing, there has been a number of complications, however, a very challenging endurance test was carried out. In this test the brake disc exhibited a better cooling capacity than in the case of the classical system. There was no occurrence of dangerous cracks or other serious damage on the brake disc . The testing at the racing circuit in the Slovak Republic provided valuable information for future optimization of the GCS system. The project participants had the opportunity to peek into the secrets of motor-sport and thus be closer to the professional racing cars on the market. As a result of this effort, a license for the use of the European patent was closed. Axially and Radially Cooled Brake Disc with Cover has been confirmed worldwide in the form of the European and American patent. The Japanese and Korean patent application is still pending. Moreover, the Czech, German, and Russian utility model as well as one European industrial design for the design of the blades of a diffuser were also approved.