Determination of air drag coefficient of a car by means of coasting

• Autorzy: Münch K.
• Konferencja: Development Trends in Design of Machines and Vehicles / XXIV Polish-German Scientific Seminar (XXIV ; 08.05.2012 ; Warszawa, Polska)
• Języki publikacji: EN

Abstrakty

EN

The air drag coefficient will usually determined by wind tunnel experiments. The boundary conditions are fixed and reproducible. The costs of wind tunnel experiments are high and connected with a significant effort. Influence of the “moving street” during the experiment is only difficult to simulate, frequently done by means of a moving belt between the wheels of the car. Therefore at the lab of Thermo-and Fluiddynamics at the Cologne Institute for Automotive Engineering a new test procedure for determination of the air drag coefficient has been developed. A serial production car “Seat Ibiza ST” was tested unchanged and with modified under surface by means of coasting. The car was accelerated up to 120 km/h on a test track (2 km). The deceleration curve due to friction and air drag was measured by a GPS tracking system. By means of a general accepted evaluation procedure (NEDC-coasting) the drag was able to determine. A separation between friction based drag and aerodynamic drag is possible. The measurements indicate a good accuracy. The mistake is less than 5 % related to the origin drag coefficient. Unfortunately the boundary condition must not be changed during the test. That means, that the weather has to be stable, dry, not windy during the tests. An unusable procedure for industrial kind of work with a given time schedule. Therefore wind tunnel tests are still necessary.

Słowa kluczowe

EN

air drag coefficient; deceleration curve; wind tunnel; NEDC-coasting

PL

współczynnik oporu powietrza; krzywa hamowania; tunel aerodynamiczny; NEDC

• Wydawca: Instytut Pojazdów Politechniki Warszawskiej
• Czasopismo: Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska
• Rocznik: 2012
• Tom: z. 5/91
• Strony: 27--32
• Opis fizyczny: Bibliogr. 4 poz., rys., tab., wykr.

Twórcy

autor

Münch K.

• Institute for Automotive Engineering, University of Applied Sciences, Cologne

Bibliografia

• [1] Besen T., Schäfer Ch.: Qualitätssichernde Maßnahmen bei der Durchführung von Ausrollversuchen eines PKW, Diplomarbeit, Institut für Fahrzeugtechnik, Labor für Verbrennungskraftmaschinen, Fachhochschule Köln,
• [2] Hucho W.-H.: Aerodynamik des Automobils, GWV Verlag GmbH, Wiesbaden, 2008,
• [3] Krauße D.: cw - Wert Bestimmung durch Ausrollversuche, Diplomarbeit, Diplomarbeit, Institut für Fahrzeugtechnik, Labor für Thermo- und Fluiddynamik, Fachhochschule Köln, 2010,
• [4] Haas V. et al.: cw - Wert Bestimmung, Interdisziplinäres Projekt, Labor für Thermo- und Fluiddynamik, Fachhochschule Köln, 2012.