Protection From Plume Blowback

The rocket motor and all external motor attachments (which may include cabling, connectors, switches, instrumentation, transducers, actuators, brackets and linkage, control units, tanks, and test-stand components) shall satisfactorily withstand the heating resulting from nozzle exhaust plume blowback that may occur during motor tailoff when testing under simulated altitude conditions. External heat loads resulting from plume blowback during simulated altitude tests (ref. 62) should be...

Test Stand Transverse Vibration

Transverse mechanical vibrations of the motor and test stand are undesirable because, in extreme situations, they may cause the motor and stand to be shaken from their foundation. Applied transient side loads that may result from nozzle motion for thrust vectoring or from other sources during testing impose problems because they may induce, sustain, or amplify transverse vibrations. So that problems of this kind may be kept to a minimum, tests often are conducted to establish the transverse...

Provisions for Increased Char and Erosion

Propellant burn rates tend to be higher when the burn surface is normal to the acceleration vector and severe thermal degradation of motor internal insulation and chamber may occur from early depletion of propellant in thinly insulated regions. 0 4 8 12 16 20 24 28 32 36 40 44 Figure 7. Increased thrust caused by spin-firing (adapted from ref. 13). For example, the increased propellant burn rate at the root of a star grain has resulted in premature exposure of the internal insulation during...

Detection of Pressure Oscillations

The occurrence of acoustic oscillations sometimes called combusion instability is an erratic and partially explained phenomenon observed in some tests. Longitudinal and transverse oscillations may arise in a motor chamber fig. 19 and result in significant deviations in the propellant burning rate and consequently in the chamber pressure ref. 41 . Figure 20 shows the influence of two classes of instability on two rocket motor pressure-time histories. High-frequency oscillations up to 50,000 Hz...

Measuring Chamber and Igniter Pressure

Most tests of solid rocket motors require a means for measuring chamber and igniter pressures. Usually, small-diameter piping or tubing connected to threaded outlets or bosses on the motor chamber is used to transmit pressure to a transducer. The locations in the motor chamber for monitoring pressure are dependent upon several factors described more fully in sec. 2.2.2 i.e., the locations are selected so that 1 the pressure path is short and dynamic response is not jeopardized 2 the pressure...

List Of Figures

1 Motor attachments for transmitting thrust during test 2 A spin-test stand and a centrifuge-test stand 3 A common means of measuring chamber pressure 4 Two methods employed to support a cluster of pressure transducers 9 5 Physical model of flow separation and static pressure characteristics 10 6 Rocket altitude cell T-3 at Arnold Engineering Development Center, Tennessee 11 7 Increased thrust caused by spin-firing 8 Plume blowback at the end of simulated altitude 9 Convective heating during...

Final Report Poseidon C3 Joint Venture Joint

A Rapid Method of Evaluating Thrust Stand Dynamic Response. CPIA No. 58A, ICRPG Solid Propellant Rocket Static Test Working Group, Addendum to Bulletin of the 2nd Meeting, Sept. 1964, p. 91. 2. Anon. HIBEX Development, January 1964 September 1965 U . Dev. 6164, Hercules Powder Co., ABL Cumberland, Md. . Unpublished, pp. 11-10, 11 figure II-1A. Confidential 3. Anon. 1965 Production Support Program Final Report U . BSD TR-361, Vol. I, Hercules, Inc., June 1967, pp. 4-60....

Test Stand Alignment

Motor thrust can be measured accurately only when the motor and thrust stand, including all supports, are precisely aligned. Measured thrust is equal to actual thrust times the cosine of the angle of misalignment. Slight misalignment of only the forward thrust vector has produced small errors. For example, if the forward thrust vector is misaligned by the fairly large angle of 2 34' the inaccuracy in thrust measurement will be about one-tenth of 1 percent for a relatively large misalignment of...

Introduction

Many tests are used for the evaluation of a solid rocket motor. Excluding flight tests, the most significant test is the captive firing of the complete motor. This monograph is restricted to consideration of testing by captive firing. The term captive-fired testing, as used in this monograph, refers to static-fired, spin-fired, or centrifuge-fired testing of a complete solid propellant rocket motor to verify design and to measure performance. Such testing may require that design provisions be...