Inertial loss

The contraction of the exhaust gas at the entrance of the inlet channels and its expansion at the exit of the outlet channels causes inertial losses. It has been shown in Konstandopoulos et al. (2001) that CFD calculations or experiments are the only means to evaluate these losses, since estimations on literature correlations (which are not specifically developed for the honeycomb structure of the DPF) are not sufficiently accurate for such evaluations. Moreover, the influence of the soot cake on these losses has never before been studied in a thorough fashion. To improve the inclusion of such phenomena in DPF... 

The data clearly can be only approximately correlated in terms of the open area fraction as shown in Fig. 27. Subsequently we studied the effect of the plug length on the inertial losses coefficient for a clean filter at the three different... 

Based on these experiments, a kind of flow-pattern map was proposed describing a region of laminar flow where viscous losses dominate, an intermediate region with secondary flow where inertial losses dominate (albeit still not turbulent) and a region of fully developed turbulent flow (see Figure 1.142) [151]. The transitional Reynolds number from the pure laminar to the secondary-flow regime increases with the ratio of bend length to hydraulic diameter. 

The first part of this equation is a viscous loss term and the second is an inertial loss term. For simple homogeneous porous media, S, can be written as... 

Even the case of "capillary-pore" membranes where is only slightly larger than the thickness of the membrane, inertial losses, especially "front-and-back-face" losses, may be significant. 

The data are interpreted using published theoretical models and the permeability, k (m ) and contraction/expansion inertial loss coefficient (dimensionless) of the monolith sample are determined ... 

Figure 2 Effect of catalytic coating on pressure drop of clean monolith Table 4 Permeabilities and inertial loss coefficients...

Coupland and McClements further elaborate food emulsions in Chapter 10, reviewing the basic theory behind the propagation of ultrasound in emulsified systems and the mechanisms behind the thermal and viseo-inertial losses. The pros and cons of different experimental techniques are also reviewed. Crystallization (formation and melting of crystals) and influence of droplet eoneentration (individual droplets and floes), as well as droplet size and droplet eharge, are all parameters diseussed by the authors. 

Inertial losses depend on the kinetic energy of the blood (DP = K l/2pv ). Because p is a constant changes occur only in the velocity. These changes are significant across a severe stenosis (6). According to the equation of continuity, flow (cross-sectional area x velocity) is the same at any point along a tube segment with no branches... 

Viscous loss tenn Inertial loss tenn... 

Wet Wall Electroinertial Precipitator. The wet wall electroinertial precipitator (WWEP) air cleaner was developed to meet the requirements of high operating efficiency, low maintenance, low operating cost, and simplicity of design. To achieve high efficiency with low pressure loss, an electrostatic precipitation was the best candidate method. A wet wall was desirable to flush the precipitate away and to minimize maintenance. Inertial effects were added to assist in moving material toward the wall and to improve the cleaning action of the water on the wall (20). 

The factor K would be 1 in the case of full momentum recovery, 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. Sci. Res., A3, 144-162 [1951-1953] and Bailey,/. Mech. Eng. Sci., 17, 338-347 [1975]), while scattered, show that K is probably close to 0.5 for discharge manifolds. For inertially dominated flows, Ap will be negative. For return manifolds the recovery factor K is close to 1.0, ana the pressure drop between the first hole and the exit is given by... 

In general, the creation of aerosols is technically difficult, expensive, and time-consuming. Moreover, patients need to learn specific inhalation techniques for the correct use of inhaler devices [26], and many have difficulty in using MDIs properly. Aerosol preparations are associated with significant losses of drug. Furthermore, due to the inertial impaction of the administered aerosol particles,... 

The dye trace thread is broken down and becomes mixed with the fluid, eventually colouring the fluid over the whole width of the pipe Inertial forces dominate Frictional losses cc fiu2 Turbulent velocity profile... 

We see that Apjl, the frictional pressure drop per unit depth of bed, is made up of two components. The first term on the right-hand-side accounts for viscous (laminar) frictional losses, cc pu. and dominates at low Reynolds numbers. The second term on the right-hand-side accounts for the inertial (turbulent) frictional losses, oc pu2, and dominates at high Reynolds numbers. For further information about flow through packed beds, see Chapter 7 An Introduction to Particle Systems . 

More recently the treatment was extended to piezoelectric devices in contact with viscoelastic media (i.e., liquids and polymers). It was then realised that if the deposited mass was not rigidly coupled to the oscillating quartz crystal, separation of inertial mass and energy losses was not possible with the measurement of the resonant frequency alone. Quartz crystal impedance in the acoustic frequencies was introduced in order to study mass and viscoelastic changes and a full electrical characterization of the crystal behaviour near resonance was employed. 

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