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CADET

Customizable Accelerator-Decelerator Equipment Tester

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Membership level

2011-2012 Team

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Team Name

CADET

Project Title

Customizable Accelerator-Decelerator Equipment Tester

Design Challenge

Instrumentation for Air Force weaponry must survive high acceleration conditions. Currently, the Air Force shoots sensor modules from light-gas guns or conventional artillery into hard targets. While this form of testing can produce high accelerations, it is inherently expensive because the sensor module and target are typically destroyed in the process. Furthermore, the acceleration profile cannot be user-specified. These two problems can be solved by adding controlled acceleration-deceleration capability. The goal of the project is to design a full-size accelerator-decelerator system and demonstrate a proof-of-concept (prototype) to the Munitions Directorate of the Air Force Research Laboratory.

Such a system has been informally dubbed the "Push-Pull Gun".

Design Summary

Team CADET will create a scaled prototype and full blueprints for the Controllable Acceleration-Deceleration Equipment Tester (CADET), to be used by the Air Force Research Laboratory (AFRL) to test the behavior of electronic equipment in high-acceleration environments. For example, sensors that will guide Air Force munitions must be designed to withstand impact forces several thousand times stronger than the force of gravity, and reliable testing methods are needed to evaluate them. Current testing methods involve shooting equipment from cannons into physical barriers—destroying the test equipment and barrier. These methods suffer from inadequacies in the following areas:

• Control of deceleration profile: deceleration magnitudes and durations experienced cannot be well-specified when simply firing into a wall
• Repeatability: using new equipment for each test run introduces significant variance in test conditions
• Logistics: producing new barriers and test equipment for each run consumes logistical resources and time

The CADET device must adhere to the following criteria provided by AFRL:

• Able to repeatedly produce user-specified deceleration profiles within tolerance
• Sustain decelerations for sufficient durations
• Generate multiple deceleration pulses
• Do not destroy the equipment under test or testing platform

Our initial design concept utilizes a surgical tubing slingshot to launch a projectile containing test equipment along a linear track whose cross section has openings on the top and bottom. The projectile will then pass through an array of deceleration sections created by water draining through nozzles from an elevated storage tank, and, as the projectile passes through these sections it will transfer momentum to the water thereby decelerating itself. Deceleration control is simplified by allowing the water nozzles to reach a steady state before each test rather than dealing with transient effects. This design meets our criteria and makes dramatic improvements over existing methods in the three aforementioned areas. Cable and pulley systems and electromagnetics were also evaluated as potential deceleration methods, but were ruled out due to infeasibility, impracticality, and safety concerns.
We have completed calculations to demonstrate the viability of our design, created basic CAD models of the device, and devised storage system to supply the water in controllable intervals, a configuration for the track, and all additional support structure. Construction of our proof-of-concept began in January and will conclude February. After which, we will iteratively refine our design through March. Once our prototype has demonstrated proof-of-concept, a design for the full-scale CADET will be communicated to AFRL in our final report, to be delivered in April.