100 kN Thrust Test Stand

100 kN Thrust Test Stand
To test and characterize engines, fuels etc. a thrust test stand is essential. In the frame of an exhibition of the Space forum 2001 (27. January) held by the Swiss Astronautics Association, we presented our new test stand. 
With this test stand both liquid engines as well as solid propellant motors with thrust up to 100 kN (10 metric tons) can be tested.  The measuring table is mounted on 8 hysteresis free "Flex"-joints (with integrated safety stop extensions). The table is made of aluminum and has many integrated "T" grooves for easy mounting of different kind of engines, valves and other equipment. The load cells can be exchanged to the respective measuring range.  At the moment, a load cell for max. 25 kN is installed.  The heavy steel frame is additionally filled with concrete to suppress possible oscillations. For transportation the Test Stand fits on a standardized "Europalett". The photo shows the test stand with the "TETHIS-I" 8 kN solid booster.
Front view of the Test Stand A closer view of one of the eight flex joints. The big advantage is their hysteresis free behavior. This makes it possible to even measure loads in the range of one Newton with a precision of 1 % (remember, this is a 100 kN Test Stand !)
Detail of one of the flex joints. It is made of heat treated  special steel, grinded and plated with electroless nickel. Detail of the thrust collector. The collector allows to mount the igniter of the booster just before firing.
Detail of the feed through. The load cell can also be mounted on this side of the load cell mounting block. The 25 kN load cell. For larger boosters the cell can be exchanged by a larger 100 kN cell using the outer threaded circle.
Click on picture to start 4 minute movie (7 MB !!)
test stand. Click to enlarge ...
The picture shows a test run with the first LOX engine under rel. low chamber pressure (o.6 MPa) using LOX/ethanol at an O/F of 1.3. In this test, the injector was equipped with only 3 injector elements (see news 1st September 02 and 11th March 02) . Tests with full chamber pressure of 2.5 MPa will be conducted as soon as we have finished the muffler system.
An overview of the test setup. One can clearly see the frozen LOX line and LOX valve, the regen. chamber with it's feeding lines, the torch igniter and several thermocouples. The LOX tank is on the top left.