Problem Statement
The team must determine a method for attaching, protecting, and reducing the drag on a battery system which will power a cooling unit on a refrigeration trailer. The system must mount to the chassis of the trailer as well as reduce the overall drag underneath the trailer. The battery module will store up to 24 kWh of energy and will be supplied in a preconfigured lithium pack with a custom case surrounding the cells.
There are two integrated parts to the system. The first part includes the mounting of the batteries, which is encompassed by the mounting system. The second part is drag reduction under the trailer and protection of the batteries from the environment which will be accomplished with an aerodynamic fairing covering the batteries. Materials must be selected to withstand the harsh environmental conditions found under the trailer, while keeping manufacturing and material costs to a minimum. The cover/fairing must be easily removable for access to the batteries.
Our senior capstone team will be designing a battery mount system with an aerodynamic fairing and prototyping a scale model of the fairing to test in a wind tunnel.
Specifications
Battery Mount System
| Description | Specification |
|---|---|
| Light Weight | Mount system plus batteries must be less than 100 gallons of diesel fuel ~ 700lb: Weighs < 700 lbs |
| Infinite Life | Brackets must be designed for 1000k loading cycles in bending due to vehicle braking |
| Corrosion Resistant | Underbody coating specified that meets current SAE standards |
| Easy Battery Removal | Removal of pack < 20 mins (theoretically) |
| Durable | Each support member must support the entire pack load ~ 400 lb axial and bending loads |
| Versatile | Must be convertible for 10 or 24 KWh sized battery packs |
Fairing
| Description | Specification |
|---|---|
| Abrasion Resistant | < 1 in^3 material loss per ft^2 surface area for 10 minutes of sand blasting |
| Drag Reduction | > 5% reduction in drag over standard trailers |
| Corrosion Resistance | Material must have “good” or above resistance to corrosion as specified by Table 2.2 from Shigley’s Mechanical Engineering Design 9th ed |