Basic Requirements Heat Flux and Pressure
The energy release system shall provide the heat flux to the motor propellant and the pressure in the motor chamber necessary to ignite the propellant and produce sustained combustion within the required time limit. Because pyrogen and pelleted pyrotechnic igniters comprise the bulk of igniters currently used in operational motors, the major portion of this section on recommended practices is devoted to these types. References are provided for other systems considered of potential value for...
BulkheadDonorAcceptor Charge Design
The TBI shall include an integral bulkhead with donor and acceptor charges located externally and internally, respectively, so that propagation through the bulkhead without adverse effect on the bulkhead integrity is ensured. The recommended design parameters for through-bulkhead initiators are included in reference 62 and references 109 through 111. The recommendations are summarized as follows 1 Suggested housing-barrier material is steel. 2 Barrier thickness should be 0.100 to 0.150 in. for...
ThroughBulkhead Initiators
As is frequently the case in the ignition field, the application of a through-bulkhead initiator TBI has preceded a comprehensive theoretical explanation of the behavior of the components involved. However, some success has been reported in relating the detonation-to-deflagration transition to the detonating velocity and resulting shock pressure. A simplified illustration of a TBI is provided in figure 6. Acceptor charge 5 8 - 18 UNF-2A Closure Sealant Ignition charge Integral diaphragm Figure...
Initiators
Proof testing of initiators involves two basic areas of evaluation 1 determination of the energy inputs necessary for initiation, and 2 determination of the energy output produced following initiation. The first area includes tests to establish electrical sensitivity to direct application of firing energy and susceptibility to induced currents and electrostatic hazards. The second area involves measurements of the quantity and rate of pressure and energy produced, as well as determination of...
Pelleted Pyrotechnics
In the broadest sense, the term pyrotechnic describes a large variety of igniter types. For purposes of this monograph, however, this group of igniters is limited to pyrotechnics in the form of pellets or large grains. Examples of these types are shown in figures 8 and 9. Figure 8. Pyrodyne igniter. Igniter body Booster charge Figure 8. Pyrodyne igniter. Igniter body Booster charge In the pelleted pyrotechnic, the pellets are retained for the bulk of their burning time by either a wire mesh or...
Delay Systems 1
An initiator shall provide any delayed functioning necessary for operational or safety purposes. Methods for providing required time delays between application of the firing current and motor ignition include both electrical and chemical systems. Where electrical means are used, conventional electronic delay components are incorporated in the firing circuit these electronic means will not be discussed here. The use of pyrotechnic delay columns as the chemical delay system for solid rocket...
HighVoltage Electroexplosive Devices Exploding Bridgewire Systems 1
3.1.2.1.1 Bridgewire Characteristics The bridgewire of an EBW shall be of a size and material that can be exploded by a very short duration pulse of very high voltage and current and can effectively transmit thermal and mechanical energy to the initiator charge. The bridgewire shall satisfy criterion 3.1.1.2.2. Adequate theoretical approaches to the design of EBW initiators have not been developed to date. However, references 50 through 57 and reference 107 include extensive developmental data...
References
1. Anon. Initiator, Electrical Design and Evaluation of. Military Specification MIL-I-23659, Rev. B, Amend, no. 1, May 17, 1967. 2. Anon. Basic Evaluation Test for Use in Development of Electrically Initiated Explosive Components for Use in Fuzes. Military Standard MIL-STD-322, Oct. 15, 1962. 3. Anon. Environmental Testing Aeronautical and Associated Equipment, General Specification for. Military Specification MIL-E-5272, Rev. C, Amend, no. 1, Jan. 20, 1960. 4. Anon. Fuze and Fuze Components,...