PR-V4 PDM5 - 22/02/2009

Gallia est omnis divisa in partes tres. There are three main differences with the previous test. The first is the propellant mixing process, which had been improved. Moreover the grains' ends had been spaced by a small anular ring (~0.25mm height). Lastly the igniter's powder quantity had been increased (~ 0.45g).
In respect to the two previous tests the average pressure corresponds to what we expected, however the combustion trend is strongly decreasing.
Igniter's gas flux ignited within 20ms the exposed surfaces.
In the following test we tried to decrease igniter's powder quantity.

Acquisition frequency [Hz]: 240
Propellant: P-1
Propellant Mass [g]: 261.5
Mean density [g/cm^3]: 1.840
Ideal density ratio: 97.4 %
Grain number: 3
Total grain length [mm]: 201.7
Port grain diameter [mm]: 8
Throat diameter [mm]: 8.5
Inhibition: External, final terminated (intergrain faces not inhibited).
Action time (ta) [s]: 0.358
Burn time (tb)[s]: =ta
Maximum thrust [N]: 1933.1
Mean thrust (tb)[N]: 931.9
Mean pressure (tb)[bar]: 98.9
Total impulse [Ns]: 341
Specific impulse [s]: 133

Environmental data:
Atmospheric pressure [mbar]: 1019
Air temperature [°C]: 15