Data-flow-dominated

Novel design methodologies and synthesis techniques for multiplexed processor architectures intended for irregular high- and medium-throughput applications. Both control-flow- and data-flow-dominated target domains are treated. 

This chapter concentrates on methods suitable for mapping high-throughput, data-flow-dominated applications onto fully application-specific, lowly... 

In domains like automotive applications and back-end speech or audio processing, the data-flow issues are more dominant than the control flow. Then, there... 

This scaling, however, introduces a factor of (D/T). This may work well where the bulk characteristics of the flow dominate, but it is not an accurate measure of turbulence if local characteristics are needed. For the same power input per unit tank volume, or holding eq. (2-18) constant with variations in impeller type, diameter, and off-bottom clearance, Zhou and Kresta (1996a) provided an extensive set of data and showed that the local dissipation can vary by up to a factor of 100. This is illustrated for the Intermig on the Visual Mixing CD affixed to the back cover of the book. The best order-of-magnitude estimate of the maximum dissipation uses the swept volume of the impeller instead of the total tank volume ... 

The facdor K would be 1 in the case of full momentum recoveiy, or 0.5 in the case of negligible viscous losses in the portion of flow which remains in the pipe after the flow divides at a takeoff point (Denn, pp. 126-127). Experimental data (Van der Hegge Zijnen, Appl. Set. Re.s., A3,144-162 [1951-1953] and Bailey, ]. Mech. Eng. ScL, 17, 338-347 [1975]), while scattered, show that K is probably close to 0.5 for discharge manifolds. For inertiaUy dominated flows, Ap will be negative. For return manifolds the recovery factor K is close to 1.0, and the pressure drop between the first hole and the exit is given by... 

The heat transfer coefficient of boiling flow through a horizontal rectangular channel with low aspect ratio (0.02-0.1) was studied by Lee and Lee (2001b). The mass flux in these experiments ranged from 50 to 200 kg/m s, maximum heat flux was 15 kW/m, and the quality ranged from 0.15 to 0.75, which corresponds to annular flow. The experimental data showed that under conditions of the given experiment, forced convection plays a dominant role. 

Data for the bulk fluid, line A, indicate that vz varies as a function of z but maintains a value near 0.75 of maximum velocity. The periodicity of vx and vy is clearly evident in the graph of line A and a 1800 out of phase coupling of the components is seen with one positive when the other is negative. This indicates a preferred orientation to the plane of the oscillatory flow and this feature was seen in all the biofilms grown throughout this study. The secondary flow components are 0.1-0.2 of the maximum axial velocity and are spatially oscillatory. The significant non-axial velocities indicate non-axial mass transport has gone from diffusion dominated, Pe = 0, in the clean capillary, to advection dominated, Pe 2 x 103, due to the impact of the biofilm. For comparison, the axial Peclet number is Pe L 2x 10s. Line B intersects areas covered by biomass and areas of only bulk... 

Many extensive models of the high-temperature oxidation process of methane have been published [20, 20a, 20b, 21], Such models are quite complex and include hundreds of reactions. The availability of sophisticated computers and computer programs such as those described in Appendix I permits the development of these models, which can be used to predict flow-reactor results, flame speeds, emissions, etc., and to compare these predictions with appropriate experimental data. Differences between model and experiment are used to modify the mechanisms and rate constants that are not firmly established. The purpose here is to point out the dominant reaction steps in these complex... 

Table 4.2 gives decomposition lifetimes extracted from the flow tube data. Keep in mind that these kinetic data are for conditions in which a combination molecule-buffer gas, molecule-molecule, and molecule-wall collisions occur. The wall surface in the flow tube was quartz, and the slight discoloration observed indicates that there was initially some decomposition on the walls. Note, however, that there was no build-up of material on the walls beyond the initial transparently thin carbonaceous coating, and no products (e.g., polymer fragments) were observed that might be expected from reaction on the walls, or from bimolecular reactions. It appears that the decomposition is dominated by true unimolecu-lar reactions however, collisions with the walls are undoubtedly important in energizing the molecules for dissociation. 

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