Flow source

Universal velocity profile for turbulent flow Source N. Scholtz, VDI-Beriche6,7-12 (1955)... 

Figure 1 (A) Laminar and (B) turbulent flow t describes the time scale, Ua represents the velocity component acting in the direction of the flow. Source From Ref. 10.

Figure 2 Eddies (large scale type) downstream of an object exposed to flow. Source Adapted from Ref. 13, Sec. 21.4 (original by Grant HL. J Fluid Mech 1958 4 149).

As the name implies, the sample is introduced into the mass spectrometer as a gas (Nier 1940). There are two types of sources, the classic viscous flow source and the continuous flow source. The viscous flow source typically consists of two identical inlet systems that are coupled to the mass spectrometer by a change-over valve, which allows rapid switching for comparison of isotope ratios measured for sample and standard gases. In the continuous flow source, samples gas is introduced as a bubble in a non-reactive carrier gas stream. 

The flow sensitivity indicates that while a detector may be accurately balanced in terms of resistance and voltage, the reference flow only reduces the flow sensitivity of the analytical column flow by a factor of three to four. Much of the drift due to flow changes comes from the flow controllers. One type commonly used today has been found to have a mass flowrate proportional to absolute temperature. Flow induced noise, however, can come from column temperature fluctuations. Even if the front of the column is fed from a perfect flow source, a temperature change in the column will lead to a viscosity change in the carrier gas. Since the gas is compressible, a transient flow change occurs in the detector. Needless to say, a fluctuation in column temperature also leads to a fluctuation in the bleed level, which affects the recorder baseline by a much more direct process. 

Figure 1.77 A triangular focusing geometry for multi lamellae flows (source IMM).

Vengosh and Spivack, 2000), S S uifate (Krouse and Mayer, 2000), CPC1 (Phillips et al., 1986 Phillips, 2000 see Chapter 5.15), and S Owater (sce Chapter 5.11) variations can be used to discriminate between multiple salinity sources. The variations of some of these tracers are presented in Figures 13 and 14. A clear distinction is shown between marine sources such as seawater intrusion or marine-derived brines (e.g.. Dead Sea), nonmarine (e.g., evaporite dissolution), and anthropogenic (e.g., sewage effluents, agricultural return flows) sources. 

Cumulative instantaneous summation of all contribution flow sources... 

Functional testing (black box) of software evaluates the outputs of a program compared to the expected output values for a range of input values. For a computer-controlled analytical system, functional testing should always include analytical hardware to verify proper parameter communication and data flow. Source code is not required, but a full set of system specifications and a description of functional routines, such as calibration algorithms, must be available. 

Figure 10-2. Streamline visualization of uniform streaming flow of a Newtonian fluid past a circular cylinder at Reynolds numbers Re = 13.1 (bottom) and Re = 26 (top). These photos were taken using a long exposure time to record the pathways of very small tracer particles in the flow. [Source with M. D. Van Dyke, An Album of Fluid Motion Parabolic Press, Stanford, CA, 1982 original photos were taken by S. Taneda. The photo depicting Re = 26 was originally published by Taneda in 1956 in the Journal of the Physical Society of Japan 11, 302-7.]...

FIGURE 4-4 Dynasafe static destruction kiln process flow. SOURCE Harley Heaton, UXB International, Inc., April 10, 2006. 

The Deitatrac (Figure 23-32) uses for the determination of oxygen consumption and COj production a dilution method with a precise constant-flow source which transforms the measurement of absolute concentrations into measurement of concentration differences and constancy of flow [32]. 

The latter interpretation is the one normally sought in the study of perfect-fluid flows we wish to find the flow pattern around some arbitrary body. This is normally done by judicious combinations of steady flows, sources, sinks, etc. When a combination is found that produces a streamline with the shape of the body in question, the flow outside the streamline is a representation of the flow around the body. The flow inside that line (i.e., inside line AB in Fig. 10.8) normally has no meaning and is ignored. 

A recent variant of this assay involves placing bacteria in a chamber between a flowing source of attractant and a flowing sink (30). This technique produces linear gradients in which the positions of individual bacteria can be registered. 

In the network model, heat flow sources through represent the heat flow rates absorbed from incident radiation Cl through C7 are the heat capacities of the discrete parts T/r) and r (r) are the temperature sources giving the temperature of the sky and the ambient air, respectively and R[j, R j, and Rlj are radiation, conduction, and convection heat transfer resistances between the discrete parts, respectively. Network element T i is the temperature source representing the inlet temperature of the working medium flowing into the nth section from the n - 1 discrete section. From the heat balance equation,... 

Heat input pressure source between points 1 and 2 of a pipe (A = constant) Acceleration pressure source Mass flow source (independent)... 

Grounded on the concept applied in CFD simulations where either a pressure boundary condition or a flow boundary condition is used, real droplet generators can be distinguished using the type of boundary condition resulting from the actuation mechanism. However, there exist also droplet generators where a combination of pressure and flow represents the correct boundary condition. In this case neither an ideal pressure source nor an ideal flow source is the correct assumption. The pressure inside the system is influenced by the flow and vice versa. Due to... 

Immediately flush with tepid potable water from a gently flowing source for at least 15 minutes. 

Notice that element C Ci in derivative causality and the switch Sw in conductance causality do not allow a flow sensor Df / in inverted causality attached to junction 11. The non-inverted flow sensor Df / has been replaced by a virtual detector Df r for residual n and a modulated flow source MSf /. Virtual detectors are distinguished from detectors of power variables by an asterisk. The modulated flow source delivers a measured flow /. 

Constant excitations to a system are represented by an effort or a flow source that provides an output of constant value. In the incremental bond graph these sources are replaced by sources of value zero. If a constant excitation, however, is to be considered uncertain, its source may be replaced in the incremental bond graph by a source modulated by the nominal value. For instance, let Se En represent a constant voltage or constant hydraulic pressure supply. If there is a relative uncertainty 8e = AE/E , then the constant effort source may be replaced in the incremental bond graph by an effort source MSe SsEn modulated by the nominal effort E obtained from the bond graph with nominal parameters. If the internal structure and the parameters of the device are known that provides the excitation and if possible disturbances acting on the device can be modelled, then an incremental bond graph model can be constructed that accounts for the uncertainty of the excitation. 

Source nodes All dependent port variables of a source node are independent of its independent port variables. This means that the dependent variables are either constant (linear case with one parameter) or the function of an input (modulated source). This means that a multiport source node can always be split into a set of (modulated) one-port sources. When the dependent port variable is an effort the source is called an effort source (node label Se). When the dependent port variable is a flow the source is called a flow source (node label Sf). A modulated source has node label MSe or MSf. 

For a bond with negligible RA at a 1-junction, the bond becomes a modulated flow source upon conditioning, thereby removing a term from the junction effort summation as illustrated in Case B of Scenario (i). 

Level 1 This threshold points to a well-known structural simplification that can be made in the bond graph, namely, the null flow source can be removed along with the 1-junction vcy without affecting the accuracy of the model. 

By dualizing the flow detector (on the model of Fig. 3.13a) which becomes a flow source SSf, /-element can be assigned with derivative causality. The ARR of (3.22) is then derived by eliminating the unknown variables in junction 1 using causal paths from known variable SSf (imposed) to the unknown variables ... 

A structural fault noted Fs corresponds to a new effort (or flow) source that causes a change in the structure of the model. Thus, the nominal model of the system is not conserved and its dynamic is altered by the presence of the fault. This difference between the system and the model generates an unbalance in the flow, mass and energy conservation laws, calculated from junctions 0 and 1 of the bond graph model. For example, a water leakage in the tank of Fig. 3.15b is a stfuctural fault. It can be modeled by a flow source Sf Yg. The model sfructure has changed from the bond graph model of the system without fault of Fig 3.15a. 

In this example, input-output pairs I t), e and E t), f2, respectively, are collocated. Hence, the left-hand side flow source and the effort detector in Fig. 4.20 can be combined into one source-sensor element SS. The same holds for the right-hand side effort source and the flow detector. The bond graph of the inverse model is... 

The inverse bond graph is obtained from the direct bond graph (Fig. 4.11) by replacing each of the two effort sources representing the voltage source and the external moment by a flow source-effort sensor, SS, as depicted in Fig. 4.24. The source-sensor elements lead to differential causality at the ports of the two I elements accounting for the self-inductance La of the rotor winding and the mechanical inertia Jm of rotor and load. That is, the inverse model has no states. Hence, the denominator of all transfer functions of the inverse model is a constant. 

Dualise the source thus the effort source becomes a flow source and vice versa... 

Figure 5.3a shows the result of applying this recipe to the system with effort actuation (when dualised, the effort source Se so becomes the flow source Sf so) one component (C ki) is in integral causality and so it is confirmed that this system is not structurally controllable with effort actuation. Conversely, Fig. 5.3b shows the result of applying this recipe to the system with flow actuation no component remains in integral causality and so it is confirmed that this system is structurally controllable with effort actuation. 

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