Velocity rocket

In rocket technology, the ratio between the burning surface of the propellant and the smallest cross-section of the nozzle. It determines the resultant pressure in the combustion chamber of the rocket (other relevant keywords -> Burning Rate, - Gas Jet Velocity - Rocket, Solid Propellant Rocket, Specific Impulse, - Thrust). 

A steady-state rocket-type combustion spray unit has been developed, called high velocity oxy fuel (HVOF), that creates a steady state, continuous, supersonic spray stream (1.2—3 mm dia) resembling a rocket motor exhaust. The portable device injects and accelerates the particles inside a barrel (rocket nozzle). It produces coating quaHty and particle velocities equal to the D-gun at 5—10 times the spray rate with significantly reduced coating costs. 

In reality, the performance curve is easy to understand. It isn t rocket. science. The performance curve indicates that the pump will discharge a certain volume or flow (gpm) of a liquid, at a certain pressure or head (H), at an indicated velocity or speed, while consuming a specific quantity of horsepower (BHP). The performance curve is actually four curves relating with each other on a common graph. These four curves are ... 

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 conservation of momentum or Newton s second law applies to a particle or fixed set of particles, namely a system. The velocity used must always be defined relative to a fixed or inertial reference plane. The Earth is a sufficient inertial reference. Therefore, any control volume associated with accelerating aircraft or rockets must account for any differences associated with how the velocities are measured or described. We will not dwell on these differences, since we will not consider such noninertial applications. 

Electroimmunoassay (rocket electrophoresis) and radial immunodiffusion (A5) lack sensitivity at low Lp(a) concentrations, and the response is influenced by the size of the apo(a) isoforms (A5, K28). Differences in migration velocity in the agarose gel lead to an underestimation of the samples with large apo(a) isoforms and to an overestimation of samples with small apo(a) isoforms. Moreover, the detection limit lies around 0.07-0.08 g/liter Lp(a), so that this method is better suited for screening and detection of individuals with elevated Lp(a) levels than for the exact measurement of the plasma Lp(a) concentration. 

In general, PBX materials are used for the warheads of rockets and guns. Thus, the detonation pressure pj represented by Eq. (9.7) is the most important parameter above all others. Since the detonation velocity Wj, can be measured more easily and more accurately than pj, performance is evaluated by measuring Wp, which is converted into pj by means of Eq. (9.7). Table 9.6 shows Wj, and p data, along with computed detonation pressures at the CJ point, for various HMX-PBX and RDX-PBXmaterials. 

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 specific impulse of a rocket motor, I, as defined in Eq. (1.75), is dependent on both propellant combushon efficiency and nozzle performance. Since is also defined by Eq. (1.79), rocket motor performance can also be evaluated in terms of the characterishc velocity, c, defined in Eq. (1.74) and the thrust coefficient, Cp, defined in Eq. (1.70). Since c is dependent on the physicochemical parameters in the combustion chamber, the combushon performance can be evaluated in terms of c. On the other hand, Cp is dependent mainly on the nozzle expansion process, and so the nozzle performance can be evaluated in terms of Cp. Experimental values of and Cpgxp are obtained from measurements of chamber pressure, p, and thrust, F ... 

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