Analysis
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(Pod pictures)
Three different shaped pods were created using modeling clay (as seen above). They were attached to a Lincoln Navigator (1/24 scale) and BMW X5 (1/18th scale) and placed in the Villanova University wind tunnel. The drag coefficient was measured on each pod at various speeds ranging from 18 to 88 mph. The goal was find which pod shape reduced the drag coefficient the most.
Lincoln Navigator-No Pod Lincoln Navigator-Pod A
BMW X5- No Pod BMW X5- Pod
The following are the results:
Table 1: Lincoln Navigator Test Results
**Note: These results are from a single trial
|
Power level |
Cd No Pod |
Cd Pod A |
Cd Pod B |
Cd Pod C |
|
15 |
0.732878 |
0.68561 |
0.640263 |
0.619285 |
|
20 |
0.618981 |
0.620939 |
0.771335 |
0.57644 |
|
25 |
0.560084 |
0.566489 |
0.608142 |
0.612786 |
|
30 |
0.561652 |
0.529199 |
0.588875 |
0.545149 |
|
35 |
0.572241 |
0.536643 |
0.619799 |
0.532668 |
|
40 |
0.541897 |
0.487421 |
0.56285 |
0.554398 |
|
45 |
0.548537 |
0.514254 |
0.548537 |
0.509682 |
|
50 |
0.560233 |
0.529847 |
0.550737 |
0.526049 |
|
55 |
0.548284 |
0.511112 |
0.549832 |
0.5266 |
|
60 |
0.548959 |
0.490572 |
0.542424 |
0.526739 |
|
65 |
0.573904 |
0.502849 |
0.533457 |
0.527896 |
|
70 |
0.524004 |
0.495307 |
0.536319 |
0.529555 |
Table 2: BMW X5 Test Results
**Note: These results are from a single trial
| Power level | Cd | Cd | Cd | Cd |
| No Pod | Pod A | Pod B | Pod C | |
| 15 | 0.426842 | 0.497982 | 0.508707 | 0.75883 |
| 20 | 0.57644 | 0.602059 | 0.649164 | 0.823753 |
| 25 | 0.629107 | 0.642029 | 0.792059 | 0.723098 |
| 30 | 0.684216 | 0.662147 | 0.76796 | 0.74693 |
| 35 | 0.683617 | 0.692062 | 0.687861 | 0.746803 |
| 40 | 0.767387 | 0.701611 | 0.701611 | 0.679522 |
| 45 | 0.710813 | 0.658245 | 0.66053 | 0.687957 |
| 50 | 0.764106 | 0.662784 | 0.693753 | 0.704564 |
| 55 | 0.720598 | 0.643391 | 0.649446 | 0.667613 |
| 60 | 0.746323 | 0.666593 | 0.673128 | 0.671706 |
| 65 | 0.733504 | 0.65917 | 0.667915 | 0.684312 |
| 70 | 0.728722 | 0.630646 | 0.651718 | 0.66956 |
Graph 1: Lincoln Navigator Results
Graph 2: BMW X5 Test Results
A cad model was developed to model the air as it flowed over a Mountaineer with a aerodynamic pod attached on the rear. When it was modeled in Fluent, the air lines showed the location of the vortex that is created as air flows over the back of the SUV. With a aerodynamic pod attachment, this vortex can be minimized. To see evidence of the vortex click here.
Cad Model
Fluent Model Analysis
*Speed was modeled at 60 mph
FEA of Trailer Hitch Attachment Mechanism
The main system to support the storage pod will attach via the vehicles trailer hitch. The system will be made of square metal tubing that will fit inside a 1.25" trailer hitch, and conform around the bumper and extend up along the rear of the SUV. The back of the pod will be directly fitted to this system. Once the cad model was created, it was analyzed in ANSYS to examine the stress levels and displacements that this mount will be subjected to.
Cad Model
Stress Analysis
The max stress level seen on the hitch was 17865 psi which yields a factor of safety of 2.05
Deformation Analysis
The max deformation that occurred was .155 inches which falls within acceptable limits
Villanova University - 800 E. Lancaster Ave.- Villanova, PA
Department of Mechanical Engineering