EXPERIMENTAL RESULTS OF FUEL CONSUMPTIONS CONSIDERING THE SPEEDS OF CITY BUSES
Authors:   Nizhny Novgorod State Technical University named after R. E. Alekseev, Nizhny Novgorod, Russia, Ilyanov S.V. , Kuzmin N.A. ,   Nizhny Novgorod State Technical University named after R. E. Alekseev, Nizhny Novgorod, Russia, Borisov G.V. ,   Nizhny Novgorod State Technical University named after R. E. Alekseev, Nizhny Novgorod, Russia
Published: July 2021

At the moment, there is a large number of dissertations and scientific works covering the issues of traction-speed and fuel-economic characteristics of vehicles, the results of which are presented in the form of: regression models, approximating dependencies, mathematical models based on multivariate analysis, including a number of additional coefficients. In this connection, the use of the results of these works in practice is limited, since it requires high qualifications of the МTЕ personnel and the use of special software and hardware. At the same time, at the department “Automobile transport” NSTU named after R. E. Alekseev developed a probabilistic-analytical method for predicting fuel consumption by road trains, considering the high-speed mode of movement, which shows a high convergence of results with actual average speeds only for uniform movement of buses with a constant average speed, which is not applicable to the assessment of fuel consumption of city buses. Based on the hypothesis put forward on the applicability of the Weibull-Gnedenko distribution for calculating the average speeds of city buses and the normal distribution for calculating accelerations during movement, the tasks of this study are formulated, expressed in the development of mathematical models reflecting the dependences of speeds and accelerations during bus movement in urban operating conditions, for planning their fuel consumption. To solve the set tasks, the following experimental studies were carried out: determination of the average coefficient of total road resistance; the actual distribution of speeds and accelerations when driving city buses; determination of the average actual value of fuel consumption when the bus is moving and when idle at stopping points. Based on the results of processing experimental studies, the possibility of using the Weibull-Gnedenko law to describe the actual speeds in urban conditions and the normal law to describe accelerations when driving city buses was confirmed, which allows planning fuel consumption using the analytical apparatus of the theory of probability and mathematical statistics and using the developed methodology in practice of motor transport enterprises. Based on experimental studies and theoretical studies in this area, an analytical method for planning fuel consumption for city buses, considering the speed of their movement, has been developed, which allows planning fuel consumption without additional experiments. Carrying out such studies for other types of motor vehicles and assessing unaccounted for indicators of road, transport and natural-climatic operating conditions will create a generalized analytical method for planning fuel consumption by vehicles in various operating conditions.