The automotive engineering fraternity is facing tremendous challenges to improve fuel economy and emissions of the internal combustion engine. The stringent CAFÉ standards for CO2 emissions are expected to become further demanding as time progresses. Indian OEM engineering experts have been considering various technology options to improve vehicle fuel economy. However, the time and costs associated with the development of these strategies and technologies remains a point of major concern and challenge.
The potential of a technology to reduce fuel consumption can be estimated in three basic ways. One approach involves developing an actual prototype engine and vehicle with the technologies under evaluation, performing the actual measurements. Some variability from test to test is although expected, this method is the most accurate but time consuming and very expensive. A second approach is Partial Discrete Approximation (PDA) that uses algorithms to add discrete technologies to the set of base vehicle configurations and then calculate their cumulative impact. However, adjustment factors used in this approach reduces the accuracy of the model.
The third approach as presented in this paper is to construct a virtual simulation model that represents engine model and its interaction with the vehicle systems. It also includes representations of the engine technologies and strategies for reducing fuel consumption, and to simulate the behavior of the vehicle over the mandatory test procedures. This method, is referred to as Closed System Simulation (CSS), is the refined process for estimation of vehicle fuel consumption. This CSS based simulation model was developed and experimentally validated. It becomes less time and cost consuming to evaluate incremental technology changes further on this virtual model for advance calibrations towards CAFÉ.