Problems of determining energy efficiency of land vehicles

Abstract

Introduction (problem statement and relevance). A great variety of vehicle types, some of which became widely used not too long ago (for instance, personal mobility devices – PMD), sets the problem of comparing such vehicles to each other for more efficient use under specified operational conditions. At present, there is no unified criterion to assess vehicle energy efficiency and to compare vehicles. The study proposes a solution to the problem.

The purpose of the study is to address the problem of determining energy efficiency and to resolve the task of developing its complex indicator that includes the maximum number of criteria and enables quite adequate and accurate assessment and comparison of various types of vehicles.

Methodology and research methods. To resolve the set task, methods of mathematical modelling were applied.

Scientific novelty and results. The new criteria proposed, such as the efficiency factor, specific speed, specific time, etc., and the new formula to determine energy efficiency, expressed as km/kW·h, allowed quite accurate and clear assessment of vehicles under various operational conditions, and comparison between vehicles. For instance, it became clear that for short distances (up to 20 km), energy efficiency of PMD is an order higher than that of a conventional passenger car, while efficiency of use of a passenger bus with full load on a route is 6 times more efficient than that of a passenger car.

Practical significance. The proposed indicators and criteria allow clear comparison of various types of vehicles between each other and their accurate assessment in terms of efficiency of use under various operational conditions, i.e. enable selection of the maximum efficient operational conditions for every vehicle type.