Flyer

In 1987 Seatde Metro purchased 10 new American built M.A.N. coaches powered by methanol. Six GM buses powered by DDC methanol engines entered revenue service at Triboro Coach in Jackson Heights, New York, 2 GM buses in Medicine Hat Transit in Medicine Hat, Manitoba, and 2 Flyer coaches in Winnipeg Transit, Winnipeg, Manitoba, Canada. An additional 45 DDC powered methanol buses were introduced in California as indicated by Table 4. Figure 11 shows the distance accumulation of alternate-fueled buses in the four California transit properties. 

Impact resistance is determined usiag flyer plate impact tests, long rod impact tests, Hopkinson bar tests (50), and the Hquid jet technique (51). Impact damage resistance is often quantified by measuring the postimpact strength of the ceramic. 

The peak pressures attainable with explosive facilities can be greatly enhanced, and the initial peak pressure can be better sustained by using a plane-wave generator to accelerate a flyer plate, which then impacts a flat specimen as shown in Fig. 3.2. This technique will generate peak pressures up to a few hundred GPa. (McQueen and Marsh, 1960 McQueen et al., 1970). 

Figure 3.2. Explosive plane-wave generator used to accelerate a flyer plate for planar impact on a specimen.

The most common form of energy deposition used for planar shock wave research has been electrical resistance heating of a metal foil which vaporizes, driving a flyer plate to a high velocity before it impacts a specimen. In a hybrid system incorporation both resistance vaporization and an electromagnetic push, velocities to 18 km/s are reported for kapton flyer plates which are... 

Osher, J.E., H.H. Chau, G.R. Gathers, R.S. Lee, G.W. Pomykal, and R.C. Weingart (1988), Shock-Wave Studies Using Plastic Flyers Driven by an Electric Gun for Hypervelocity Impact on Selected Materials, in Shock Waves in Condensed Matter 1987 (edited by S.C. Schmidt and N.C. Holmes), Elsevier Science, New York, pp. 673-676. 

The propagation of a shock wave from a detonating explosive or the shock wave induced upon impact of a flyer plate accelerated, via explosives or with a gun, result in nearly steady waves in materials. For steady waves a shock velocity U with respect to the laboratory frame can be defined. Conservation of mass, momentum, and energy across a shock front can then be expressed as... 

We assume that in (4.38) and (4.39), all velocities are measured with respect to the same coordinate system (at rest in the laboratory) and the particle velocity is normal to the shock front. When a plane shock wave propagates from one material into another the pressure (stress) and particle velocity across the interface are continuous. Therefore, the pressure-particle velocity plane representation proves a convenient framework from which to describe the plane Impact of a gun- or explosive-accelerated flyer plate with a sample target. Also of importance (and discussed below) is the interaction of plane shock waves with a free surface or higher- or lower-impedance media. 

The physical state of the sample before and after impact is sketched in Fig. 4.6(a). Positive velocity, indicating mass motion to the right (in the laboratory), is plotted toward the positive, u, axis. Hence, in the initial state 0, the target B is at Up = 0 and P = 0, whereas the initial state in the flyer plate O is Up = Ufp and P = 0. Upon interaction of flyer plate A with target B, a shock wave propagates forward in the sample and rearward in the flyer plate. Because the pressure and particle velocity are continuous at the flyer-... 

If the Hugoniot of the flyer plate (.4) and the target (B) are known and expressed in the form of (4.7), the particle velocity Ui and pressure Pi of the shock state produced upon impact of a flyer plate at velocity, Ufp, may be calculated from the solution of the equation equating the shock pressures in the flyer and driver plate ... 

Calculate the final shock state pressure and density from the measured shock velocity of 5.77 km/s in a sample of glass (initial density 2.204 g/cm ) which is mounted onto a driver plate of pure Cu. The Cu driver plate is impacted at 4.5 km/s by a Ta flyer plate. Use the impedance match methods. 

Samples are most frequently shock deformed under laboratory conditions utilizing either explosive or gun-launched flyer (driver) plates. Given sufficient lateral extent and assembly thickness, a sample may be shocked in a onedimensional strain manner such that the sample experiences concurrently uniaxial-strain loading and unloading. Based on the reproducibility of projectile launch velocity and impact planarity, convenience of use, and ability to perform controlled oblique impact (such as for pressure-shear studies) guns have become the method of choice for many material equation-of-state and shock-recovery studies [21], [22]. 

This site and hotline provides information about the science of ozone depletion, regulations under Title VI of the Clean Air Act Amendments (CAAA) of1990 designed to protect the ozone layer, information on methyl bromide, flyers about the UV index, information for the general public, and other topics. Hours 10 00 a.m. - 4 00p.m., weekdays, EST. 

First flight of the Wright Flyer, December 17, 1903. (Library of Congress)... 

---