Rocket motor design

S olid Propellant ProcessingFactors in Rocket Motor Design, Space Vehicle Design Ciiteiia Monograph, SP-8075, NASA, Airport, Md., 1971. 

Kubota, N., Principles of Solid Rocket Motor Design, Pyrotechnics Chemistry, J. of Pyrotechnics, Inc., Whitewater, CO (2004), Chapter 12. 

Thrusters are rockets for maneuvering and controlling the attitude of space vehicles. The usual monopropellant for thrusters is catalytically decomposed Hydrazine. The usual catalysts are iridium, rhodium or ruthenium and their mixts. For a review of Hydrazine thrusters see Refs 33, 34 35. Russi (Ref 34) emphasizes that, in spite of many studies and the general acceptance and apparent success of hydrazine thrusters, new rocket motor design is still largely empirical. A biproplnt consisting of Hydrazine mixed with Hydrazine Nitrate has also been tried in thrusters but is no longer popular... 

The challenge of predicting the plume radiance is describing the thermodynamic combustion process within the rocket chamber, the plume structure and the rocket plume chemical composition. The factors guiding these processes are the rocket motor design parameters, as well as the rocket motor fuel chemistry. In addition, environmental conditions have a significant impact on the plume structure and the plume chemical composition. 

The data set of rcxzket motor features consisted of 14 elemental rcxzket propellant compositions and 4 rocket motor design parameters. The elemental compositions were molar values calculated from a 100 kg basis and included the elements C, H, O, N, Al, K, F, Cu, Pb, S, Cl, Si, Ti and Fe. The design parameters consisted of the nozzle throat temperature (Tc), pressure (Pc), nozzle diameter (Dr) and the expansion ratio of the outlet nozzle diameter to the nozzle throat diameter (Ec). 

A correlation map of the rocket motor design features in figure 4 shows that there is very little correlation between the variables representing the rocket motor parameters. 

Fig. 4. A map of correlation factors of the rocket motor design parameters and chemistry to investigate the presence of potentially redundant correlated information in the underlying...

The building of data-driven models in this study was constrained by the sprarsity of the available data, as there were only 18 independent samples (rocket motor designs) available. In addition the input and output data were highly multivariate with 18 rocket motor design parameters and 146 spectral wavelengths in the middle IR band. One advantage is that the IR spectral measurements were repeated a number of times (4 to 44 repeats per rocket motor). 

In contrast, there is also current interest in investigating PAN-based fibers in low thermal conductivity composites [62], Such fibers are carbonized at low temperature and offer a substitute to rayon-based carbon fibers in composites designed for solid rocket motor nozzles and exit cones. 

Another consideration in the design of a rocket motor is the boost velocity, or velocity which the vehicle will attain when all the propellant has been consumed. Neglecting drag losses, this velocity becomes... 

The discussion of the important design considerations of solid-propellant motors presented in Section I has shown the importance of the steady-state burning rate of the propellant. The particular mission for a rocket motor to... 

Fig. 13.21 shows another example of oscillatory burning of an RDX-AP composite propellant containing 0.40% A1 particles. The combustion pressure chosen for the burning was 4.5 MPa. The DC component trace indicates that the onset of the instability is 0.31 s after ignition, and that the instability lasts for 0.67 s. The pressure instability then suddenly ceases and the pressure returns to the designed pressure of 4.5 MPa. Close examination of the anomalous bandpass-filtered pressure traces reveals that the excited frequencies in the circular port are between 10 kHz and 30 kHz. The AC components below 10 kHz and above 30 kHz are not excited, as shown in Fig. 13.21. The frequency spectrum of the observed combustion instability is shown in Fig. 13.22. Here, the calculated frequency of the standing waves in the rocket motor is shown as a function of the inner diameter of the port and frequency. The sonic speed is assumed to be 1000 m s and I = 0.25 m. The most excited frequency is 25 kHz, followed by 18 kHz and 32 kHz. When the observed frequencies are compared with the calculated acoustic frequencies shown in Fig. 13.23, the dominant frequency is seen to be that of the first radial mode, with possible inclusion of the second and third tangential modes. The increased DC pressure between 0.31 s and 0.67 s is considered to be caused by a velocity-coupled oscillatory combustion. Such a velocity-coupled oscillation tends to induce erosive burning along the port surface. The maximum amplitude of the AC component pressure is 3.67 MPa between 20 kHz and 30 kHz. - ...

The burning rate of propellants is one of the important parameters for the design of rocket motors. The burning rate is obtained as a function of pressure and of initial temperature, from which pressure exponent of burning rate and temperature sensitivity of burning rate are deduced. 

Igniter for Rocket Motor. An explosive item designated to ignite the propelling charge in a rocket motor (Ref 40a, p 90). See also Igniter, Ram-Jet Engine in Section 3, Part C, Fig 29... 

Jan 1969, pp 2-3 [Through Bulkhead Initiator (TBI) was designed in 1961 for use in rocket motor and gas generator ignition systems and since that time thousands of units have been fired with no reported failures of any kind. The TBI s are available in a variety of configurations. For example, the Standard McCormick Selph Unit, P/N 805845 (manufd by the McCormick Selph,... 

Baka Piloted Rocket Bomb was a suicide weapon designed to be controlled by a human pilot. It resembled a plane, was carried beneath.the fuselage of a bomber and released near its target. Three Type 4 Mk 1 Rocket Motors provided propulsion after Baka was released from the mother plane. The entire HE content of the Baka (1135 lbs of Type 91 Expl) (Trinitroanisole) was in the warhead of the nose. Baka was 19 ft 10 inches long with wingspread 16 ft 5 inches. Its warhead had Nose and Tail Fuzes (pp 116—17, Fig 88)... 

Rocket Launcher and Rocket Motor Model 10 (p 172) was designed to propel the 60-kg aircraft bomb out of an inclined trough. The launcher was constructed of wood and metal with legs made of iron pikes. The launcher channel was a right angle wooden trough, ca 20 ft long with a motor and bomb positioner... 

Rocket Motors (Roketto Hasshaki) are devices designed to provide propulsive power (propel or launch) to a Bomb or Rocket Projectile of an inclined trough or barrel called Launchers One of such Rocket Motors is described and illustrated in the book of Tantum Hoffschmidt (Ref 7, p 172) under the title Rocket Launcher and Rocket Motor Model 10 . It is briefly described here under Rocket Launchers. They are also described in Ref 2, pp 120-1 Another Rocket Mortar (Type 4 Mk 1) is described here under ROCKET BOMBS as a device used to propel Baka Piloted Rocket Bomb (Ref 2, p 118)... 

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