Simulation when testing a car for fuel efficiency on the road and on a bench with running drums

Abstract

Fuel consumption is a complex indicator that characterizes the efficiency of vehicle use, the energy perfection of the vehicle design, the level of the vehicle's technical condition, and a variety of operating conditions.

Changes in the technical state of the components and systems of the car leads to increased energy losses, which ultimately increases fuel consumption and reduces the power of the car. If you monitor the energy losses in each vehicle unit, then the fuel consumption can be used to diagnose not only the general condition of the vehicle, but also to localize the malfunction by the units. The general assessment of the technical condition of the car can be carried out according to the experimental and calculated data of fuel consumption. An individual assessment of the technical condition of the units can also be assessed by private efficiency and indicated fuel consumption.

The aim of the work is to further improve the methodology and develop an algorithm for diagnosing the technical condition of a car by changing the indicator fuel consumption and efficiency of the car.

To solve this goal, mathematical relationships and an algorithm for calculating fuel consumption and vehicle efficiency by units (indicator and mechanical engine, transmission and car suspension) were proposed.

The following diagnostic tasks can be solved using simulation:

- evaluate the quality of the car's functioning;

- issue recommendations on the types and amounts of preventive maintenance and repairs for this vehicle;

- to develop rational options for the use of diagnostic devices and equipment for various components and systems of the car, while simulating their functioning.

With regard to cars, physical modeling can be carried out when determining (standardizing) fuel consumption, exhaust gas toxicity, vehicle efficiency, rolling resistance and adhesion to the road, efficiency of braking systems, ride smoothness, etc.

The results of modeling fuel consumption using the proposed mathematical model, depending on the braking torque of the stand, coincide with a certain degree of accuracy with the results of road and bench tests of a car in various driving modes.

To ensure the compliance of the test modes of cars with real ones, it is necessary, using the results obtained, to select the load modes of bench diagnostics so that they maximally correspond to road conditions.