1 Introduction
1.1 Developments in Rural BEV Application
1.2 Facility Test Environment in Heilbronn-Franconia Region
2 Digital Prototypes and Simulated Driving Cycles
2.1 Creating a Digital Mock-up
2.2 CFD Based Roof Extension Development
2.3 Driving Cycles for the Rural–Urban Use Case
Street type | Characteristics |
---|---|
City streets with urban traffic | Driving speed up to 60 kmh−1, frequent stop-and-go, intermittent acceleration necessary |
Country roads | Driving speed between 60 and 90 kmh−1, no stops, certain acceleration necessary |
Highway | Driving speed up to 130 kmh−1, constant driving, hardly any acceleration necessary |
2.4 Simulation Model for Vehicle Drive Cycles
Parameter | Abb. | Value | Source |
---|---|---|---|
Tire friction coefficient | fR | \(0.01 + \frac{v}{{10^{4} }}\frac{s}{m} + \frac{{v^{4} }}{{2 \cdot 10^{7} }}\frac{{s^{4} }}{{m^{4} }}\) | [23, p. 50] |
Powertrain efficiency coefficient | η | 0.78 | [24, p. 124] |
Recuperation efficiency coefficient | ηrecu | \(0.741 = 0.95 \eta\) | [25, p. 19] |
Mass surcharge factor for the moment of inertia | k | 1.25 | [26, p. 82] |
3 Result Evaluation for Designs and Energy Consumption
3.1 Enlargement of the Interior Space
3.2 CFD Simulation Results
VW e-up! load-up! | + roof box | + high roof variant | |
---|---|---|---|
Drag coefficient cd | 0.311 | 0.44 | 0.343 |
Reference area Ax (m2) | 2.07 | 2.30 | 2.31 |
cd∙Ax (m2) | 0.646 | 1.014 | 0.791 |
Drag force (20 ms−1) (N) | 152 | 239 | 186 |