Gas inertia

For viscous dominated flows, it can be assumed that the gas inertia and the gas gravitational forces are negligible. By dropping the gas inertia and gravity time from the gas momentum equation and simplifying the dimensionless drag coefficient to the linear viscous term, the set of dimensionless equations does not include gas-to-solid density ratio as a parameter. 

The influence of gas density on the gas-liquid interfacial area could be related to the flow patterns and to the interpenetration between gas and liquid. It is probable that the gas-liquid interface results from two distinct mechanisms. The first one is based on the extent of the solid surface where liquid films could develop (wetting of particles), virtually controlled by fluid velocities and liquid properties. The second mechanism depends on the kinetic energy content of the gas phase. The more important the gas inertia, the more important is the contribution of fine gas bubbles penetrating liquid films. 

Question by D. H. Tantam, British Oxygen Company, Ltd. The efficiencies given appear high, bearing in mind (1) the high gas inertia in the flow passages within the piston and (2) the throttling which occurs with piston-operated parts. Are the efficiency values for the gas expansion process alone, or for the overall machine ... 

Particle inertia/gas viscous force Gas inertia/Gas viscous force Inertia/gravity force Solid inertia/Gas inertia force... 

The inertial coefficient G2 is dependent on whether gas or liquid is inside the capillary (phase B). When the capillary radius is larger than 0.1 mm, the length is smaller than 10 mm, the meniscus height is of the order of the capillary radius and the phase B is a gas. Then the gas inertia can be neglected as compared to the inertia of the added mass of the liquid near the... 

Clift et al. (2005) showed that ignoring these two unsteady terms (in particular the Basset integral) can lead to errors for a rapidly changing motion in liquid. Fortunately, in the case of gas cyclones we can safely ignore them, even when calculating the rapid, small-scale turbulent motion, since the gas inertia is relatively small. In fact, it turns out that this is true even for the case... 

Inertial collectors. In inertial collectors, an object is placed in the path of the gas. An example is shown in Fig. 11.1. While the gas passes around the shutters, particles with sufficiently high inertia impinge on them and are removed from the stream. Only particles in excess of 50/um can reasonably be removed. Like gravity settlers, inertial collectors are widely used as prefilters. 

Molecular moments of inertia are about 10 g/cm thus 7 values for benzene, N2, and NH3 are 18, 1.4, and 0.28, respectively, in those units. For the case of benzene gas, a = 6 and n = 3, and 5rot is about 21 cal K mol at 25°C. On adsorption, all of this entropy would be lost if the benzene were unable to rotate, and part of it if, say, rotation about only one axis were possible (as might be the situation if the benzene was subject only to the constraint of lying flat... 

Fig. 3-11 shows that, foi watei, entropy and heat capacity ai e summations in which two terms dominate, the translational energy of motion of molecules treated as ideal gas paiticles. and rotational, energy of spin about axes having nonzero rnorncuts of inertia terms (see Prublerris). 

Inertial impaction involves the removal of contaminants smaller than the pore size. Particles are impacted on the filter through inertia. In practice, because the differential densities of the particles and the fluids are very small, inertial impaction plays a relatively small role in Hquid filtration, but can play a major role in gas filtration. 

On approaching a collecting body (fiber or liquid droplet), 0 porticle corried along by the gas stream tends to follow the stream but may strike the obstruction because of its inertia. Solid lines represent the fluid streamlines oround a body of diameter Dt, and the dotted lines represent the paths of particles that initially followed the fluid streamlines. X is the distance between the limiting streamlines A and B The fraction of particles initially present in a volume swept by the body that is removed by inertiol interception is represented by the quantity X/Dt, for a cylindrical collector and (X/Dt,) for a sphericol collector... 

Direct interception occurs when the fluid streamline carrying the particle passes within one-half of a particle diameter of the filter element. Regardless of the particle s size, mass, or inertia, it will be collected if the streamline passes sufficiently close. Inertial impaction occurs when the particle would miss the filter element if it followed the streamline, but its inertia resists the change in direction taken by the gas molecules and it continues in a... 

If the probe velocity is less than the stack velocity, particles will be picked up by the probe, which should have been carried past it by the gas streamlines. The inertia of the particles allows them to continue on their path and be intercepted. If the probe velocity exceeds the stack velocity, the inertia of the particles carries them around the probe tip even though the carrying gases are collected. Adjustment of particulate samples taken anisokinetically to the correct stack values is possible if all of the variables of the stack gas and particulate can be accounted for in the appropriate mathematical equations. 

At this point, as far as shaking forces go, the gas forces do not make a contribution. If the rod load or bearing loads are to be analyzed, the gas forces must be calculated and added vectorially to the inertia forces to... 

Cyclones use inertia to remove particles from the gas stream. The cyclone imparts... 

Interception A special case of impingement, in which a particle is trapped on a fiber due to the effect of Van der Waals forces rather than inertia. The interception of a particle in a particle collection device occurs when the particle follows a gas streamline round a collector at a distance less than the radius of the particle. 

In addition to the gas load, the rod and cros.shead pin bushing is subject to the inertia forces created by the acceleration and deceleration of the compressor reciprocating mass. The inertia load is a direct function of crank radius, the reciprocating weight, and speed squared. The total load imposed on the crosshead pin and bushing is the sum of the gas load and the inertia load and is referred to as the combined rod load. ... 

A widely used type of dust-collection equipment is the cyclone separator. A cyclone is essentially a settling chamber in which gravitational acceleration is replaced by centrifugal acceleration. Dust-laden air or gas enters a cylindrical or conical chamber tangentially at one or more points and leaves through a central opening. The dust particles, by virtue of their inertia, tend to move toward the outside separator wall from where they are... 

M. Amon and C. D. Denson [33-34] attempted a theoretical and experimental examination of molding a thin plate from foamed thermoplastic. In the first part of the series [33] the authors examined bubble growth, and in the second [34] — used the obtained data to describe how the thin plate could be molded with reference to the complex situation characterized in our third note. Here, we are primarily interested in the model of bubble growth per se, and, of course, the appropriate simplification proposals [33]. Besides the conditions usual for such situations ideal gets, adherence to Henry s law, negligible mass of gas as compared to mass of liquid, absence of inertia, small Reynolds numbers, incompressibility of liquid, the authors postulated [33] several things that require discussion ... 

Tables 10.1, 10.2, and 10.3e summarize moments of inertia (rotational constants), fundamental vibrational frequencies (vibrational constants), and differences in energy between electronic energy levels for a number of common molecules or atoms/The values given in these tables can be used to calculate the rotational, vibrational, and electronic energy levels. They will be useful as we calculate the thermodynamic properties of the ideal gas.

El0.7 Carbonyl sulfide (OCS) is a linear molecule with a moment of inertia of 137 x 10-40 g em2. The three fundamental vibrational frequencies are 521.50, 859.2, and 2050.5 cm-1, but one is degenerate and needs to be counted twice in calculating the entropy. A Third Law measurement of the entropy of OCS (ideal gas) at the normal boiling point of T = 222.87 K andp = 0.101325 MPa gives a value of 219.9 J-K- -mol"1. Use this result to decide which vibrational frequency should be given double weight. 

---