Lockheed Martin - Team 1 - Testing Results/Analysis

Our purpose of testing the IED/Explosion System is to optimize the proper level of pressure of the system that safely but sufficiently stimulate the senses of trainees in the model. Standardized testing of the prototype model determined if the behavior and performance of the actual model will meet Lockheed Martin’s wind simulator needs. A qualitative testing approach was used to analyze the IED System prototype, in which, the force of the air burst, level of distraction, and level of the noise output from the nozzles was analyzed through a survey taken from those individuals that experienced the wind bursts from the system.

To test and analyze the IED/Explosion System prototype, two individuals sat in testing model and with one individual in the gunner position. A video clip was played to catch the attention of the individuals inside the testing model. Then, the 2-way off/on switch was opened for 2 seconds to provide air burst to the testing model at 20 psi. The three individuals rated the air burst experience using the survey in the table below. The procedure was repeated as the pressure increased at 20 psi increments up to 120 psi.

Your Experience	20 psi	40 psi	60 psi	80 psi	100 psi	120 psi
Force of Air Burst	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5
Noise Level	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5
Level of Distraction	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5

To ensure that the IED/Explosion System prototype had a safe noise level, all nozzles used for the prototype meet the Occupational Health and Safety Administration (OHSA) requirements and standard CFR 1910.242 (b). Our IED/Explosion System prototype will not operate more than 0.5 hours per day at a constant noise level and therefore the maximum sound level that our nozzles can output is 110 dBA according to OSHA Standard 29 CFR 1910.95 (a) seen in table below.

As a result, the nozzles used for the prototype output 82 dBA of noise and the OHSA allowable noise exposure requirement and standard was met.

Upon the completion of all of the surveys, the responses were compiled into a graph so that the most comfortable level of stimulation could be determined. Based on the rating scale for the survey, the most desired rating was between 3 and 4. It was determined that a rating within this range should effectively and safely stimulate the senses of the occupants. As shown by the results of the survey, 60 psi proved to be the optimal pressure level that met the desired rating level.

The next step in the analysis of the prototype was to relate the survey results to a quantifiable measurement. The distances that the nozzles were positioned from the occupants in the prototype were measured. The nozzles in front of the occupants were measured 10” away, the nozzles behind the occupants were measured 15”, and the gunner nozzle was approximately 24” away from the occupant in the gunner turret. A pitot-static tube was used to measure the pressure of the nozzles at their respective distances.

At the optimal operating pressure of 60 psi found from the surveys, the velocity testing indicated that this pressure produced a gunner velocity of 18 mph, a front nozzle velocity of 19 mph, and a rear nozzle velocity of 13 mph. The velocities were calculated from the measured pressures and are displayed below.

The testing and analysis showed that the optimal tank pressure was 60 psi. Due to the more distractive environment of the actual training simulator, it is recommended that a tank pressure of 80 psi be used for a greater emphasis of an IED explosion.