Archive for July, 2009

As predicted last week, testing the window with full pressure and cold temperature has blown up the test box with no damage to the window.

Test Setup: test box and video camera in the blast container

The test box was filled with offcuts of blue foam and sealed up. More blue foam was placed on top to hold the dry ice. The dry ice surface temperature was -100F and it froze the window surface down to -70F. Then we pressurised it to above the fuselage design pressure and held that pressure for 30 minutes.
Then we increased the pressure until the box exploded. Watch the 30-second video below.

The explosion was surprisingly violent, destroying the thermometer which was sitting on top of the box. The blue foam inside the box didn’t seem to do much to reduce the explosive force.

Aftermath

The end result is that we reached design temperature and more than twice the design pressure with no effect on the window. This polycarbonate is extremely tough stuff.

The video can also be downloaded in Window Media (WMV) format and Quick Time (MOV) format. Each file is 2.2Mb and is identical to the Flash video above.

We pressurised a test window for the first time today. We ran it up to the full design pressure although we did not test the (higher) proof pressure. There were no leaks and no problems with the window.

window-test setup

I expect we will find that the window is unbreakable. The test box will almost certainly fail before the window does.

Jim Murray and Pat McLaughlin have been working on phase 2 of the project for several months now. We have only just gotten around to adding them to the “team” page on the web site.

Patrick is the owner of Mountain High, which makes the best oxygen systems available for regular gliders. He has been working on the cabin pressurisation system for the Perlan.
Jim has been working with Jeff Bozanic (who will be added to the team page soon) on the rebreather system.

The rebreather oxygen system has been tested in a simple form. Jim Murray has put together a re-configurable system using simple plumbing parts. This allows us to test different configurations to work out which is best.

Einar Enevoldson tests the rebreather, supervised by James Murray

The tests were very encouraging. The CO2 scrubber lasted much longer than predicted and the heat and moisture build-up were much less than predicted.
Now we know what configuration works best, we will continue testing the rebreather in cold and altitude conditions.