During this stage, we went to see the pulse jet with our advisor Mr. Wolz to see the current state of the engine. In the next stage we will disassemble the pulse jet engine to make sure that all the parts and subassemblies work as expected.

In this stage we disassembled the pulse jet engine. From a visual inspection, most of the parts looked like they would still be operational. A few things that we plan to update are the ignition system, the compressed air and gas tubes, the fuel system, and to repaint the warnings on the stand.

In this stage we focused on pulling apart the valve head assembly of the pulse jet. The original fabricators of the engine made sure that it was well put together and used a heat resistant bonding agent, something along the lines of Loctite 271, to make sure that the assembly stayed together during operation. After our team was able to get the valve head apart, we performed a visual inspection of the reed valves which seem to be in good condition. While the top-end of the pulse jet was disassembled we also replaced all of the gas and compressed air tubing to ensure that there were no cracked tubes or leaks in the dispersal system.

Contrary to our initial visual inspection, once we were able to get inside the pulse jet we were able to find that the current reed valve petals had multiple chips on the ends. We ordered new petals to replace the old ones to ensure proper function of the pulse jet. The first picture shows an example of chips found in one of the reed valve petals.

Another issue we discovered when disassembling the pulse jet was that we were unsure of the efficicacy of the spark plug embedded in the system. We were able to test the spark plug with an arduino board and electrical set-up similar to the one that the completed system will use. From this test we were able to determine that the arduino was not capable of creating enough voltage to operate the spark plug so a voltage stepper will be needed to make the electrical system operational. The second picture shows Isaiah testing the spark plug.

In this stage of the project we focused on calibrating the load cell and pressure transducer to obtain accurate readings during the testing phase.

In the stage we added new parts to the pulse jet that allow the pulse jet to function and also add to its functionality.

The final pulse jet assembly is capable of acquiring thrust, inlet pressure from the air and gas lines, the fuel mass flow rate, temperature, and velocity data. The following equipment is utilized to collect the above listed data:

• Load Cell - Thrust

• Pressure Transducers - Inlet pressures, Fuel mass flow rate

• Temperature Sensors - Temperature dispersion from combustion

• Pitot Tube - Exit velocity (calculated from dynamic pressure at exit)

At this stage of the refurbishment process we focused on demonstrating that the pulse jet operated as expected. The video to the left shows a short test of the pulse jet in operation.