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Showing posts from August, 2020

Low pressure temperature performance of KNSb propellant

Tests were performed on the temperature effect on burn rate for KNSb as follows: Four grains were prepared as follows: 3" Diameter grain 5.5" long  1" Core 3.5" Diameter casting tube  1040 grams propellant +- 50 grams Humidity controlled to < 10% The grains were placed into a low pressure test motor .85" nozzle throat - .02" 98mm phenolic liner KN 65  Single Grain motor from Rick Maschek Notes: Four tests were performed with one failing due to an improperly seated snap ring.    Force data was measured directly and the pressure was obtained basd on the nozzle throat and Cf value for the motor. Test 1: Grain Temperature 55oF +- 5      Data: Peak Pressure 6.7 PSI +-7 Average Pressure 5.5 PSI +- 6 Peak Force 5 lbs +- 3 Average Force  4 +- 2  Burn Time: 18.3s +-  1.8s  Note:  The low pressure of this burn makes it difficult to estimate burn time.  The original estimate was on the order of 16 seconds.   Test 2:...