Nitrocellulose and BKNO 3 Based Igniters for Gun Systems.
- PDF / 725,140 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 26 Downloads / 152 Views
Nitrocellulose and BKNO3 Based Igniters for Gun Systems. Eugene Rozumov, Carlton P. Adam, Thelma G. Manning, Joseph M. Laquidara, Kimberly Chung, Duncan Park, Viral Panchal 1 1
U.S. Army RDECOM-ARDEC, Picatinny Arsenal, NJ 07806, U.S.A.
ABSTRACT Common igniters such as black powder, benite, and boron potassium nitrate (BKNO3) are routinely employed in all calibers of gun systems. Armament Research Development Engineering Center (ARDEC) has pursued efforts to improve the ignition of gun propellants which has been demonstrated to be the root cause of many tribulations for gun systems. We have developed several extrudable nitrocellulose-BKNO3 based igniter materials that are more energetic, and exhibit smaller ignition delay times than most traditional igniters. We have demonstrated this via static firing. High speed video during static testing has demonstrated significantly more consistent, intense, and rapid flame generation in comparison to Benite leading to improved ignition effectiveness of the propellant bed. INTRODUCTION The ignition of the propellant bed in large caliber gun systems has been determined to be critical for proper gun performance.1 Inadequate ignition can lead to hangfires, misfires, loss of accuracy, and catastrophic failure of the gun system. A large majority of these problems arise due to negative differential pressure waves occurring between the two ends of the chamber in the gun and can be traced back to improper ignition.2 Firing begins by the initiation of a small bit of primer material that is either impact or electrically sensitive. The release of the primer energy then ignites the igniter material usually situated inside a perforated metal tube in the center of the propellant bed. Ignition of the propellant bed occurs via two mechanisms. Firstly, the condensed phase material generated from the combustion of the igniter makes direct contact with the propellant bed and transfers its heat via conduction. In a complimentary process, the hot gases generated by the combustion of the igniter material travel across the propellant bed and transfer their heat to the propellant via convection.3 This is a slower process than conduction, but doesn’t seem to develop pressure differentials as readily. Attempts to isolate the actions of the condensed and gas phases on ignition were demonstrated to be inconclusive since a dynamic equilibrium exists between molecules in the gas phase and condensed phase, which allows the two phases to constantly interconvert. The importance of the condensed and gas phases of the igniter combustion products has always been controversial,4 but the current belief is that the condensed phase plays a more critical role in ignition of the propellant bed than does the gas phase. Traditional ignition materials include black powder and benite, with benite being a roughly 1:1 mixture of black powder and nitrocellulose. Boron potassium nitrate (BKNO3) has been used in rocket fuels for some time and is very similar to aluminum in its combustion characteristics owing to both aluminu
Data Loading...
