The energy losses produced by aerodynamic drag are widely recognised as an area where improvement will lead to efficiency gains in vehicles at potentially modest cost. As such, it is an essential component of the overall drive towards the adoption of low carbon technology within the automotive industry. The project took an integrated approach to this problem, adapting automotive design processes and technologies to the design, manufacture and test of innovative vehicle body forms and devices.
Comprehensive technology benchmarking study
- Conceptual designs for body devices to reduce vehicle drag
- Computer simulation model validated through wind-tunnel testing of concept vehicles fitted with aerodynamic features and devices
Use of model scale and full scale tunnels for the development of aerodynamic concepts and to carry out correlation
Validated results of fixed ground wind tunnel testing by testing at a moving ground facility
Business Impact – New Products and Processes
MIRA has further developed its capability in Large Volume Airflow Visualization (LVAV) techniques. The advantages of LVAV over current techniques such as Particle Image Velocimetry (PIV), is that it covers a large three-dimensional volume rather than a slice of the flow, whilst still offering accurate, transient, 3D position and velocity data capture. Rapid postprocessing of the data provides engineers with a detailed insight into the flow structure; something which usually takes much longer when using traditional CFD methods.
Base pressures were a key area of research and development, and several concepts were tested, leading to significant reductions in drag. Drag reduction from wheel, and wheel arch odifications, was also investigated at model and full scale levels, as well as in fixed and moving ground tests.
Ricardo has performed a sensitivity analysis of aerodynamic drag over various drive cycles. This analysis has helped the investigation and evaluation of a range of state of the art passive and active devices and concepts used to improve aerodynamic performance. Ricardo used the vehicle fuel consumption and electric range model (called ‘VSIM’ and developed in Matlab Simulink) used in other areas of the project to quantify the electric energy consumption, regenerative braking and electric vehicle range over real world and legislative drive cycles (Artemis and NEDC).
The results are being considered by Jaguar Land Rover and Tata Motors European Technical Centre (TMETC) for incorporation into new vehicle wheel and wheel bay designs.
For Coventry University, the knowledge and experience gained through this workstream, in addition to its existing design, simulation and prototyping assets, has provided a step change in its engineering capabilities and expertise. It can now offer a comprehensive aerodynamics service from design critique to a managed test programme.