Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Spatial theory

The amplification rates are different in different directions and of course, different d are themselves function of ip. For three- dimensional waves the spatial theory comes with lot more complications as compared to temporal theory. In addition to the wave orientation angle ip, the amplification direction ip must also be specified before any calculation can be made. Once again, if... [Pg.34]

In temporal theory, one uses ui = u>r and in spatial theory one uses a = Ur and [3 = fdr in Eqn. (2.3.34). The imaginary part of the group velocity is usually neglected. For parallel flows, one can form a spatial amplification rate by following the wave with the group velocity i.e. [Pg.34]

Consider the application of spatial theory for a wall-bounded external flow. On the top panel of Fig. 2.5, we once again show the neutral curve... [Pg.48]

This is evident from the formulation see for example, the retention of two modes in Eqn. (2.4.5) that only considers excitations at the boundary y = 0, those decay with height. It is therefore clear that the characteristic determinant of (2.4.8) will extract only those modes that are triggered by wall excitation and those decay with height. Thus in an experiment, TS waves are naturally going to be produced by excitation of the shear layer at the wall- as was demonstrated in Schubauer Skramstad s experiment. When the frequency of the ribbon in the experiment is fixed, TS waves are predicted as a consequence of satisf3ung the dispersion relation of (2.4.8) via the spatial theory. [Pg.65]

However, the experimental studies relate to spatial growth of disturbances as the flow system is always excited by fixed frequency sources. Hence a spatial theory is preferred to study the stability of non-isothermal flows. Despite the distinction between temporal and spatial methods, the neutral curve, however, is identical. Iyer Kelly (1974) reported results using linear spatial theory under parallel flow approximation for free-convection flow past heated, inclined plates. Tumin (2003) also reports the spatial stability of natural convection flow on inclined plates providing the eigen spectrum. [Pg.197]

Meyer was known for his researeh in asymptotic analysis, partial differential equations, plasma physics, water waves, meteorology, and in gas dynamics. In the latter field he explored supercritical nozzle flows. In water waves theory, the fundamental hydraulics were studied in collaboration with Joseph B. Keller (1923-), including wave refraction and resonance, extending short wave asymptotics to obtain notable advances in the spatial theory of the classical water waves with applications to both coastal and shelf oceanography. He was a member of the Australian Academy of Sciences. Meyer was an individualist who marched to no one s drum but his own. [Pg.614]

In what follows we make a comparison of the temporal and spatial theories presented above, with the experimental findings of Hertz and Hermanrud [32]. In particular we compare with the set of results in their Figure 5. [Pg.64]

The Place of Forced Migration Location and Spatial Theory... [Pg.112]

This is Kirkwood s expression for the chemical potential. To use it, one needs the pair correlation fimction as a fimction of the coupling parameter A as well as its spatial dependence. For instance, if A is the charge on a selected ion in an electrolyte, the excess chemical potential follows from a theory that provides the dependence of g(i 2, A) on the charge and the distance r 2- This method of calculating the chemical potential is known as the Gimtelburg charging process, after Guntelburg who applied it to electrolytes. [Pg.474]

In two classic papers [18, 46], Calm and Flilliard developed a field theoretic extension of early theories of micleation by considering a spatially inliomogeneous system. Their free energy fiinctional, equations (A3.3.52). has already been discussed at length in section A3.3.3. They considered a two-component incompressible fluid. The square gradient approximation implied a slow variation of the concentration on the... [Pg.754]

Voth G A 1992 A theory for treating spatially-dependent friction in classical activated rate processes J. Chem. Phys. 97 5908... [Pg.897]

Haynes G R, Voth G A and Poliak E 1993 A theory for the thermally activated rate constant in systems with spatially dependent friction Chem. Phys. Lett. 207 309... [Pg.897]

The higher-order bulk contribution to the nonlmear response arises, as just mentioned, from a spatially nonlocal response in which the induced nonlinear polarization does not depend solely on the value of the fiindamental electric field at the same point. To leading order, we may represent these non-local tenns as bemg proportional to a nonlinear response incorporating a first spatial derivative of the fiindamental electric field. Such tenns conespond in the microscopic theory to the inclusion of electric-quadnipole and magnetic-dipole contributions. The fonn of these bulk contributions may be derived on the basis of synnnetry considerations. As an example of a frequently encountered situation, we indicate here the non-local polarization for SFIG in a cubic material excited by a plane wave (co) ... [Pg.1279]

Do we expect this model to be accurate for a dynamics dictated by Tsallis statistics A jump diffusion process that randomly samples the equilibrium canonical Tsallis distribution has been shown to lead to anomalous diffusion and Levy flights in the 5/3 < q < 3 regime. [3] Due to the delocalized nature of the equilibrium distributions, we might find that the microstates of our master equation are not well defined. Even at low temperatures, it may be difficult to identify distinct microstates of the system. The same delocalization can lead to large transition probabilities for states that are not adjacent ill configuration space. This would be a violation of the assumptions of the transition state theory - that once the system crosses the transition state from the reactant microstate it will be deactivated and equilibrated in the product state. Concerted transitions between spatially far-separated states may be common. This would lead to a highly connected master equation where each state is connected to a significant fraction of all other microstates of the system. [9, 10]... [Pg.211]

In HMC the momenta are constantly being refreshed with the consequence that the accompanying dynamics will generate a spatial diffusion process superposed on the ini rtial dynamics, as in BGK or Smoluchowski dynamics. It is well known from the theory of barrier crossing that this added spatial... [Pg.313]

Seetion treats the spatial, angular momentum, and spin symmetries of the many-eleetron wavefunetions that are formed as anti symmetrized produets of atomie or moleeular orbitals. Proper eoupling of angular momenta (orbital and spin) is eovered here, and atomie and moleeular term symbols are treated. The need to inelude Configuration Interaetion to aehieve qualitatively eorreet deseriptions of eertain speeies eleetronie struetures is treated here. The role of the resultant Configuration Correlation Diagrams in the Woodward-Hoffmann theory of ehemieal reaetivity is also developed. [Pg.3]


See other pages where Spatial theory is mentioned: [Pg.34]    [Pg.35]    [Pg.65]    [Pg.168]    [Pg.64]    [Pg.23]    [Pg.111]    [Pg.112]    [Pg.34]    [Pg.35]    [Pg.65]    [Pg.168]    [Pg.64]    [Pg.23]    [Pg.111]    [Pg.112]    [Pg.127]    [Pg.29]    [Pg.107]    [Pg.125]    [Pg.664]    [Pg.666]    [Pg.755]    [Pg.889]    [Pg.1539]    [Pg.2361]    [Pg.2368]    [Pg.2380]    [Pg.2383]    [Pg.2557]    [Pg.2816]    [Pg.610]    [Pg.472]    [Pg.170]    [Pg.128]    [Pg.130]    [Pg.2]   
See also in sourсe #XX -- [ Pg.113 , Pg.116 ]




SEARCH



© 2024 chempedia.info