Inertial principle

The effect of external forces on the motion of bodies, which tend to remain in the original dynamic condition, is the basis of the inertial principle. In the presence of a force, the motion of a body is changed in direction of action of the force. When polluted gas flows around a curved separating area, then it is possible to observe different curvatures of the paths of particles and the carrying gas trajectory, with a retention of the particle on a given area. This principle may be used in different types of dry mechanical separators. 

Wet inertial scrubbers. The inertial principle is used for the separation of dust particles in this type of scrubber. Sprayed layers of small objects or sprayed rods are used. This type of scrubber also includes units, where the stream of purified gas and a pressure difference force the water from the open surface into S-shaped slit, where it is mi, ed with purified gas. 

Scmbbers make use of a combination of the particulate coUection mechanisms Hsted in Table 5. It is difficult to classify scmbbers predominantly by any one mechanism but for some systems, inertial impaction and direct interception predominate. Semrau (153,262,268) proposed a contacting power principle for correlation of dust-scmbber efficiency the efficiency of coUection is proportional to power expended and more energy is required to capture finer particles. This principle is appHcable only when inertial impaction and direct interception are the mechanisms employed. Eurthermore, the correlation is not general because different parameters are obtained for differing emissions coUected by different devices. However, in many wet scmbber situations for constant particle-size distribution, Semrau s power law principle, roughly appHes ... 

Deep Bed Filters. Deep bed filtration is fundamentally different from cake filtration both in principle and appHcation. The filter medium (Fig. 4) is a deep bed with pore size much greater than the particles it is meant to remove. No cake should form on the face of the medium. Particles penetrate into the medium where they separate due to gravity settling, diffusion, and inertial forces attachment to the medium is due to molecular and electrostatic forces. Sand is the most common medium and multimedia filters also use garnet and anthracite. The filtration process is cycHc, ie, when the bed is full of sohds and the pressure drop across the bed is excessive, the flow is intermpted and solids are backwashed from the bed, sometimes aided by air scouring or wash jets. 

Microscopic Balance Equations Partial differential balance equations express the conservation principles at a point in space. Equations for mass, momentum, totaf energy, and mechanical energy may be found in Whitaker (ibid.). Bird, Stewart, and Lightfoot (Transport Phenomena, Wiley, New York, 1960), and Slattery (Momentum, Heat and Mass Transfer in Continua, 2d ed., Krieger, Huntington, N.Y., 1981), for example. These references also present the equations in other useful coordinate systems besides the cartesian system. The coordinate systems are fixed in inertial reference frames. The two most used equations, for mass and momentum, are presented here. 

Other types of inertial collectors which might be used for particulate separation from a carrying gas stream depend on the same theoretical principles developed for cyclones. Table 29-2 summarizes the effect of the common variables on inertial collector performance. 

This type of technology is a part of the group of air pollution controls collectively referred to as "wet scrubbers. Orifice scrubbers are also known as self-induced spray scrubbers, gas-induced spray scrubbers, and entrainment scrubbers. The operating principle is based on the removal of air pollutants by inertial and diffusional interception. 

The only force opposing the downward flow of the heated air or upward flow of the cooled air is a buoyancy force. In their analysis, Helander and Jakowatz also suggested accounting for inertial forces due to the entrainment of room air. However, this suggestion is not in an agreement with a principle of momentum conservation used in most of the existing models for isothermal jets. 

Mach s principle, as formulated by Wheeler [wheel64a], states that the inertial properties of an object are determined by the energy-momentum distribution throughout all of space. 

Inertial sensors based on atom interferometer basic principle... 

We present here a summary of recent work with light-pulse interferometer based inertial sensors. We first outline the general principles of operation of light-pulse interferometers. This atomic interferometer (Borde et al., 1992 Borde et al., 1989) uses two-photon velocity selective Raman transitions (Kasevich et al., 1991), to manipulate atoms while keeping them in long-lived ground states. 

We are applying the principles of statistical experimental design to the development of low-density polymer foams for use as direct-drive high-gain targets for Laser Inertial Confinement Fusion (ICF). Both polystyrene (PS) and resorcinol-formaldehyde (RF) foams are being developed. 

As was pointed out earlier, when we have considered the physical principles of the ballistic gravimeter and the pendulum an influence of the Coriolis force was ignored. Now we will try to take into account this factor and consider the motion of a particle near the earth s surface. With this purpose in mind let us choose a non-inertial frame of reference, shown in Fig. 3.5a its origin 0 is located near the earth s surface and it rotates together with the earth with angular velocity a>. The unit vectors i, j, and k of this system are fixed relative to the earth and directed as follows i is horizontal, that is, tangential to the earth s surface and points south, j is also horizontal and points east, k is vertical and points upward. As is shown in Fig. 3.5a SN is the earth s axis, drawn from south to north, I is the unit vector along OiO, and K is a unit vector parallel to SN. 

The principle of inertial impaction is employed to sample aerosols aerodynamically for characterization of particle size and will be dealt with theoretically later in this chapter. 

The collection efficiency of particles at a stage of an impactor is based on curvilinear motion and assumes Reynolds numbers for flow greater than 500 but less than 3000. Figure 8A illustrates the principle of inertial sampling in which particles with high momentum travel in the initial direction of flow of an airstream impacting on an obstructing surface and those with low momentum adjust to the new direction of flow and pass around the obstruction. The efficiency of this phenomenon can be described as follows ... 

Centrifugal separators take the idea of an inertial separator a step further and make use of the principle that an object whirled about an axis at a constant radial distance from the point is acted on by a force. Use of centrifugal forces increases the force acting on the particles. Particles that do not settle readily in gravity settlers often can be separated from fluids by centrifugal force. 

The design of a cross-flow filter system employs an inertial filter principle that allows the permeate or filtrate to flow radially through the porous media at a relatively low face velocity compared to that of the mainstream slurry flow in the axial direction, as shown schematically in Figure 15.1.9 Particles entrained in the high-velocity axial flow field are prevented from entering the porous media by the ballistic effect of particle inertia. It has been suggested that submicron particles penetrate the filter medium and form a dynamic membrane or submicron layer, as shown in... 

The problem relates directly to the constancy of c, which implies that the velocity of light is independent of both the motion of its source and the direction of propagation, a condition that cannot hold in more than one Newtonian inertial frame if the Galilean principle of relativity applies. Since there is no evidence that the laws of physics are not identical in all inertial frames of reference the only conclusion is that the prescription for Galilean transformations needs modification to be consistent, not only with simple mechanics, but also with electromagnetic effects. 

Inertial impaction is most widely applied for the characterization of inhalation systems. The principles of particle separation on the basis of inertial and drag forces have been well described for many different applications. Theoretical cut-off diameters (for particles with 50% collection efficiency) of impactors can be calculated on the basis of Stokes numbers for nozzles of a particular design [8,120]. Many different designs are available, but only a few are described in the United States and European Pharmacopoeia [121,122]. 

Thus, it is a matter of record that a satisfactory incorporation of Mach s principle within general relativity can be attained when the constraint of closure is imposed. However, there is still the point of view that, because general relativity allows solutions that give an internally consistent discussion of an empty inertial spacetime—whereas it is operationally impossible to define an inertial frame in the absence of matter—then the theory (general relativity) must have a non-fundamental basis at the classical level. 

The analysis described above makes it clear that there is some kind of relationship between the distant galaxies, and the idea of relative inertial mass - and the statement of the existence of such a relationship—is termed Mach s principle. 

---