6.01 volts, that’s what we hit on Saturday. For the last two years on the Magnetohydrodynamic development program our goal has been to achieve a 5000 millivolt (5 volt) system. Our first couple of dozen tests were in the 30 millivolt range. Saturday’s test number 105 blew past our goal and nailed 6010 milivolts! We’ve now officially ramping up for the 10 volt system.
Today we got the system for measuring the speed of the wave in the shock tube working. We will be able to measure speed in the tube up to Mach 3. The chart is from a test run of the instrumentation. It wasn’t measuring waves but rather me smacking it with a pen. Tomorrow it gets installed in the tube.
Julian, our amazing intern, assemble this pair of high resolution electrodes for the MHD program. Instead of solid plates each electrode is an array of wires. Each wire is connected to the datalogger sampling 200 times a second. This way we can compare the exact power output in relation to the magnetic field. We can then go back an optimize the solid electrodes.
Yesterday we got a lot of spaceship building practice in. Musicians practice there violins before a concert right? However there are few opportunities for spaceship building practice. At JPA we use submarine building for a spaceship building practice. Yesterday we cut the recesses for the fore and aft ballast tank port frames. Its rather like notching the hole in the wall to fit the door frame.
We got all four port frames recessed.
We conducted two MHD tests last night. First first produced no data. We had conducted a dry test before the firing. A dry test is when we run the data logger on the fully prepared system however the motor is not fired. Instead a battery is connected to the plates. We check the and if you see the batter voltage you know the system is ready. The dry test was successful but there was no data from the live firing. While disassembling the system we discovered that the ground wire on the data cable had broken. It was apparently hanging on by a single strand during the dry test and came off when the test rig was rolled out to the parking lot.
On second second run it unit just plain old wouldn’t fire. After four hours of epic ninja battles with the test gear we got a good test. Sometimes your gear just gets old. This was firing 97. I’m just glad everything starting failing all at once rather then put us in agony for weeks.
We’re getting ready to start testing the airship’s drag reduction systems. The main tool we will be using is a mach two shock tube. A shock tube is a very short duration wind tunnel. It ‘s made of a long tube with a burst plate at one end and test chamber at the other. The tube is pumped down to vacuum then the plate at the end is burst open. This causes a supersonic wave to travel down the tube into the test chamber.
We have a 10000 samples per second recorder so we can measure the speed of the wave. The first goal of the system is to be able to turn it on with out it imploding. After that we’ll slowly start increasing the speed of the system. We hope to have it running at Mach 2.2 within a year.