Velocity determination

Figure 2.13. (a) x-t and (b) P-u diagrams for the rigid-piston problem. State 0 is at the origin of the P-u plane, state 1 must be on the Hugoniot of fluid with the particle velocity determined by piston velocity. 

A is commonly measured, and V determined, to calculate Q. The velocity V is determined at several points, in the center of equal duct areas, and averaged. Table 32-2 shows one commonly accepted method of dividing stacks or ducts into equal areas for velocity determinations. 

Fig. 32-6. Pitot tubes for velocity determination. Source "Annual Book of Standards" (3). Note English units were used by the American Society for Testing and Materials.

The scaled velocity can be calculated with Eq. (9.3.17). By applying the curve in Figure 9.8, a value for scaled range is found, from which the actual range can be calculated. This is performed for the initial velocity determined by method 1. The density of the ambient atmosphere is assumed to be 1.3 kg/m. In this case, fragment shape and mass are parameters, so two fragments are considered. The first consists of the end cap, with a mass of 123 kg, = 1.86 m (diameter of the vessel = 1.53 m), and Q = 0.47 (Table 9.8). The other fragment consists of... 

Terminal setding velocity determined by Stokes Law, of particle under acuon of gravity, ft/sec... 

Jr, C.W. Plummer, R.P. Woodburn V. Philip-chuk, Detonation Velocity Determinations and Fragment Velocity Determinations of Varied Explosive Systems and Conditions , National Northern Corp Final Summary Report NNC-F-13, Contract DAI-19-020-50l-ORD-(P>58 (Feb 1958) 12) Anon, EngDesHdbk, Explosives Series, Properties of Explosives of Military Interest , AMCP 706-177 (Jan 1971), 213-225... 

In a recent study of the transport of coarse solids in a horizontal pipeline of 38 mrrt diameter, pressure drop, as a function not only of mixture velocity (determined by an electromagnetic flowmeter) but also of in-line concentration of solids and liquid velocity. The solids concentration was determined using a y-ray absorption technique, which depends on the difference in the attenuation of y-rays by solid and liquid. The liquid velocity was determined by a sail injection method,1"1 in which a pulse of salt solution was injected into the flowing mixture, and the time taken for the pulse to travel between two electrode pairs a fixed distance apart was measured, It was then possible, using equation 5.17, to calculate the relative velocity of the liquid to the solids. This relative velocity was found to increase with particle size and to be of the same order as the terminal falling velocity of the particles in the liquid. 

A compression wave of low intensity is well known in ordinary sound waves in the air, or in other media. Sound is propagated with a velocity determined by the following equation ... 

In general terms, as has already been mentioned, plastic deformation is a transport process analogous with electrical and thermal conductivity. These involve an entity to be transported, a carrier that does the transporting, and a rate of transport. In the case of electrical conductivity, charge is the transport entity, electrons (or holes) are the carriers, and the electron net velocities determine the rate. In the case of plastic deformation, displacement, b (cm) is the transport entity, dislocations are the carriers, N ( /cm2), and their velocities, v (cm/sec) determine the shear deformation rate, d8/dt. In two dimensions, the latter is given by the Orowan Equation ... 

Electrophoresis. Electrophoresis, the movement of charged particles in response to an electric potential, has become very important in biochemistry and colloid chemistry. In the present study an apparatus similar to that described by Burton( M2-M5) was used. A U-tube with an inlet at the bottom and removable electrodes at the two upper ends was half filled with acetone. The a Au-acetone colloidal solution was carefully introduced from the bottom so that a sharp boundary was maintained between the clear acetone and the dark purple colloid solution. Next, platinum electrodes were placed in the top ends of the U-tube, and a DC potential applied. The movement of the boundary toward the positive pole was measured with time. Several Au-acetone colloids were studied, and electrophoretic velocities determined as 0.76-1.40 cm/h averaging 1.08 cm/h. 

Craig. S.E, Fishbein, W., Rittenbach, O.E., Continuous-Wave Radar with High Range Resolution and Unambiguous Velocity Determination , IRE Trans. Mil Electronics, vol. MIL 6. No. 2. April 1962, pp. 153-161. 

The number of PSRs with known transverse velocities is continuously growing. New velocity determinations are based on a new model of galactic distribution of free electrons (Cordes, Lazio 2002). Unlike the situation 10 years ago, when updated data on free electrons distribution led to nearly doubling of distances (and, correspondingly, transverse velocities), results of Cordes and Lazio brought serious corrections only for distant PSRs. 

Figure 5.23. Comparison of velocity in model required to produce a drag force equal to buoyant weight of particle, with velocity determined experimentally...

In this type of representation, all combustion events are collapsed into a discontinuity (the wave). Thus, the unknowns are uu u2, p2, T2, and P2. Since there are four equations and five unknowns, an eigenvalue cannot be obtained. Experimentally it is found that the detonation velocity is uniquely constant for a given mixture. In order to determine all unknowns, one must know something about the internal structure (rate of reaction), or one must obtain another necessary condition, which is the case for the detonation velocity determination. 

The sedimentation velocity determination is dynamic and can be completed in a short period of time. The sedimentation equilibrium method gives quantitative results, but long periods of time are required for centrifugation at relatively low velocities to establish equilibrium between sedimentation and diffusion. 

In the next section of Addnl Ref O, Evaluation of Parameters , it is stated that the parameters, y, a, and B/Q, which appear in the LSZK equation of state, must be evaluated by using experimental data and it is explained how this is done on pp 9 10. As an example, compressed TNT of various densities was investigated. Detonation velocities determined by LSZK expression (34) proved to be in good agreement with those detd by the empirical formula ... 

Detonation Velocity Determination. See under Detonation Rate Determination... 

Muzzle Velocity Determination. See Initial (or Muzzle) Velocity of Projectiles... 

Rate of Detonation Determination. See Detonation Rate (or Velocity) Determinations... 

The velocity-determining streamline. is always the axial one, since the wave will travel at the speed determined by the maximum values of Pj (pressure) and W2 (particle velocity) on the C-J plane... 

Jaffe et al (Ref 3), in the course of determination of the shock pressure required to initiate detonation of an acceptor in the shock sensitivity test, found that the velocity of the front as sensed by the pressure probe method, falls behind the true velocity of the shock front as the shock is attenuated. It has also been found that the maximum transmitted shock velocity generated by the two Tetryl pellets and measured in Lucite is 4.6mm/frsec. Shock velocities determined by optical method, shown in Table 3, p 25, run between 2.701... 

Refractive Index and Dispersion. The velocity of light varies depending upon the density of the medium in which it is propagating. In a vacuum, the speed of light is a constant, c, which has a value of 3.08 x 10 m/s. In any other medium, such as a gas, liquid, or solid, the velocity is given by the variable, v. The ratio between these two velocities determines the index of refraction, n, sometimes called the refractive index ... 

Fig. 31. Falling ball viscometer. Lines /Q and t are the timing lines for velocity determinations.

The dependences of wave velocity on the ratio of cubic to quadratic processes, described by eqns (11.43) and (11.44) are shown in Fig. 11.6. The quadratic curve always lies below the cubic result, but the two are tangential at q = 1/2, c = yfl. Numerical computations reveal the following detail concerning the stability of the respective solutions. For q < i, where cubic dominates quadratic, it is the velocity determined by eqn (11.43) which is selected by the system. Above q = j, however, the quadratic character takes over, and the minimal velocity described by eqn (11.44) emerges dominant. 

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