No abstract

No abstract

Abstract. This paper reports the results of a study into operating parameters of an system consisting of an SI engine and a drivertrain in a Fiat Panda passenger car in the conditions of a variable load. The analysis was primarily concerned with the variability of fuel consumption resulting of the changing load applied to the driving wheels in the conditions of a test performed on dynamometer rollers. The bench test included a dedicated driving cycle in which a constant linear speed of the car was changed every 10 km/h and subsequently maintained for registration and analysis purposes. The focus of the study involved the identification of the points characterized with the minimum specific fuel consumption. Throughout the test, the load applied to the transmission was alternated by simulating an increase of road inclination for which the variability of the engine efficiency was analyzed.

In this work, the authors focused on analyzing the energy efficiency and dynamics during car acceleration, featuring investigation of acceleration dynamics under various acceleration intensities. The tests were performed in the speed range between 45 km/h and 120 km/h, at a constant gear ratio. This enabled obtaining variable dynamic parameters of the acceleration process, ranging from about 0.1 to 1.4 m/s2 , and recording variation in fuel consumption from 6.28 to 27.03 dm3 /100km. The study focused on determining the relation between fuel consumption, energy efficiency and vehicle acceleration depending on the available drivetrain power. The relation between fuel consumption and vehicle acceleration was described by using the dynamic index. The proposed dynamic index takes into account the energy (from burned fuel) and vehicle acceleration intensity to obtain an objective metric for characterizing the acceleration process. The aforementioned index takes the form of the passenger car movement energy quality index and can be related to widely known physical properties, thus ensuring its universality. The index expresses the energy expenditure within the time needed to accelerate a vehicle weighing 1kg by a 1m distance. As opposed to other criteria that are applied to the assessment of passenger cars dynamics, the index shows a high determination coefficient R2 in excess of 0.99, and can be used as a universal metric to test other vehicle types.

No abstract