Static test of N2O liquid / solid hybrid rocket motor

The data below were generated during a static test of a N2O/PVC hybrid rocket motor.

  • The N2O tank was 3" diameter by 18" length.

  • The combustion chamber held a PVC grain 2.875" OD x 2.290 ID x 18" length.

  • The injector/valve was a 0.250" OD x 0.190" ID Nylon tube in a UC configuration.

  • Ignition was a significant problem:

    1. 0.75" lenght x 2.25" diameter slice of APCP in the plastic tube. When the UC valve opened, the slug extinguished and was blown to the bottom of the motor.
    2. A Wildman ignitor and two 50 grain Pyrodex slugs taped to the Nylon fill line. The slugs lit and burned completely, the N2O began to flow, but the motor did not light.
    3. Smaller injector (less mass flow) plus three 1/2" x 2.25" APCP slugs *glued* into the PVC tube plus a Wildman ignitor. This motor lit.

    With 130 lb-sec to 150 lb-sec thrust generated in test 3, this motor was significantly underpowered. N2O mass consumed was approx 1 kg and PVC mass consumed was approx 112 grams. Obviously, the N2O fill was incomplete.

    Test Stand Data From Test 3

  • Unfortunately the sensor measuring pressure in the combustion chamber did not work

  • Photos