Loughborough University, Department of Aeronautical and Automotive Engineering
Part of this project was to measure the aerodynamic drag of PAT vehicles in a convoy of four vehicles. The models were 1/16 scale and were based on ULTra vehicles.
Models with 1 and 0 separations in the wind tunnel
Drag measurements were made with spacings of 1, 0.75, 0.5, 0.25 and 0 vehicle lengths for each position of the convoy.
Graph showing results of PAT tests
| Condition | Cd (Average) |
| Single PAT vehicle | 0.489 |
| 1 vehicle spacing | 0.471 |
| 0.75 vehicle spacing | 0.455 |
| 0.5 vehicle spacing | 0.427 |
| 0.25 vehicle spacing | 0.411 |
| 0 vehicle spacing | 0.273 |
Full size cross-sectional area of vehicles is 2.766 m2
Measurements were made in the in the Loughborough University Department of Aeronautical and Automotive Engineering wind tunnel, which has the following characteristics:
| Wind tunnel design | Open circuit 'horseshoe' design |
| Working section type | Closed working section |
| Working section velocity | 47m/s |
| Working section size | 3.6m x 1.92m x 1.32m |
| Turbulence intensity | <0.1% |
| Velocity variation | <0.3% |
| Balance load ranges | +/- 120N |
| Accuracy for drag measurement | 0.01% |
The balance is an underfloor, 6-component, virtual-centre, Aerotech balance