Flow guiding

This represents the linear effect of tip speed and the square of impeller size on the flow of a specific impeller. Referring to Figure 12-46, very low flow coefficients for a specific type of centrifugal or axial flow machine cause excessive wall friction or leakage losses, and very high-flow coefficients tend to he subject to turbulence losses due to insufficient flow guiding. ... 

Figure 4.91 Demonstration of flow guiding in a liquid flow-splitting unit which consists of three tanks, six interdigital separation-layer micro mixers, a multiple channel segmenter and six tubular sections [140].

The influence of channels, i.e. flow-guiding internal structures, also accounts for the overall residence time distribution in the square. This will be demonstrated by the observation of particles emitted at the structure inlet. The path of such an... 

The same calculation was executed for a structure with the same outer dimensions but without flow-guiding internal structures, i.e. channels (Figure 4.96). The particles were emitted at the same positions as before but they did not follow the same routes as before because no guiding elements were present. In fact some parts of the square were not even reached by these particles, showing that the residence time in these areas is theoretically infinite. 

Obviously the characteristic distribution of the structured square, as expected, is much closer to the ideal plug flow reactor than to the laminar flow reactor. This desired behavior is a result of the channel walls, which are flow-guiding elements and pressure resistors to the flow at the same time. Two of the streamlines are projecting with a residence time of more than 0.4 s. These are the streamlines passing the area close to the wall of the distribution area, which introduces a larger resistance to these particles due to wall friction. This could, for example, be accounted for by a different channel width between the near wall channels and the central channels. 

The functioning of the liquid-flow guiding was demonstrated with the formation of iron rhodanide as a test reaction in a device built of three liquid-flow splitting units and six interdigital separation layer micro mixers (see Figure 4.91) [141]. 

A device for mixing components in a solution or dispersion without moving mechanical elements. Stationary flow-guiding elements are built into a device, frequently a section of pipe, and they induce mixing and dispersion by repeatedly dividing and recombining partial streams of the flowing material. Also termed motionless mixers . 

In utilization of externally wound tubular membrane elements in modular assemblies for conventional systems operations, that is, selective separation via the circulation of pressurized feed across membrane surfaces, flow guide tubes were found to be essential for the proper distribution and control of feed flow. This was achieved singularly by the use of individual element shrouds or flow tubes creating an annular gap through which feed stock was circulated across membrane surfaces. 

Fig. 7.25 Flow guiding illustration. The position of the middle stream is controlled by adjusting the outer two flow streams [287. ...

This bubble-actuated microfluidic switch could be effectively used for the one shot of liquid in both single-output and multi-output modes on demand. The reversible motion of the liquid is one further research direction. The long-term goal of this research work could be to develop integrated bioanalytical devices with the functions for specific flow guiding, specific flow injection, and precise liquid volume control. 

Pnmaty loop, in-vessci internals X Flow guiding stracture, steam separators, steam driers, spray nozzles, feedwater spargers, core support plate and gnd... 

The reactor tank is a cylindrical vessel of 15 m height and 4.8 m inner diameter, manufactured from stainless steel. The reactor tank wall thickness is 20 mm. Inside the tank a reactor coolant flow guiding structure of 1.6 m diameter is installed, with a lower inlet chamber at the bottom below the core and connections to hot legs at the top. In the upper part of the reactor tank, primary heat-exchangers are installed and fixed on a support frame on which there are also drums for spent fuel storage. Water circulation in the reactor tank is natural without boiling. The reactor tank is installed in a concrete cavity lined with carbon steel, 20 mm in thickness. The inner diameter of the reactor cavity is 5.2 m, and its height is 16 m. The reactor pool is covered by a lid sealed with a hydroseal. 

The time step is 0.4 seconds irtilizing a semi-implicit fluid flow guided matrix reordering solver. The seawater simulation has been calibrated with tidal and current measurements and wind data have been fed into the atmosphere simulation. Ideally the Henry coefficient shall be dependent on temperature and salinity fields supplied by the hydrodynamic computation. The numerical demonstrator shown in figure 3 shows the coupled simulation of tracer in sea and atmosphere. The differing plume travel-direction in sea (eastward) and atmosphere (southward) can be recognized. 

FLOW GUIDE MSTRU NTATI0N SUPPORT PLATE... 

Also at temperatures above 700 K thermal decoupling of the sample and the permanent magnet inside the (hot) reaction vessel is mandatory. Convection flows initiated by temperature gradients have to be suppressed or at least reduced by appropriate flow guide tubes. 

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