Radial flow method

Sample application of the radial flow method. In this sample application, we are to determine the maximum clamping force and injection pressure required to mold an ABS suitcase shell with a filling time, tf=2.5 s. For the calculation we will use the dimensions and geometry schematically depicted in Fig. 8.49, an injection temperature of 227°C (500 K), a mold temperature of 27°C (300 K) and the material properties given in Table 8.8. 

THERMAL CONDUCTIVITY OF INSULATING FOAMS BY A RADIAL FLOW METHOD. M.S. THESIS. 

Experimental measurements remain the most reliable way to determine permeability. The two most widely used techniques for measurement of the in-plane permeability are the rectilinear flow method and the radial flow method. In a rectilinear flow experiment the reinforcement is usually placed in a rectangular mould and resin is injected fiem a side gate and allowed to permeate the reinforcement in only one direction. 

Heardman et al. [11] described a radial flow method to measure permeability under transient flow, where neither the pressure nor the flow-rate is considered constant. They obtained good agreement with experiments using the normal constant pressure setup for assemblies of woven fabrics. They also showed that, using error analysis on the equation used to calculate permeability, the estimated error due to the parameters used to determine permeability (e g. pressure, viscosity and time) is in the range of 8-16%. However, they did not quantify the range of measured permeability values for their reinforcements and hence did not compare it to the estimated error. 

Boyce, M.P., and Bale, Y.S., A New Method for the Calculation of Blade Loadings in Radial-Flow Compressors, ASME Paper No. 71-GT-60, June 1971. 

Rotary motion (and surface vortex) can always be slopped by inserting projections in the body of the fluid when these are at the side if the tank they are called baffles, and this is the method most commonly used to obtain good mixing in large industrial equipment. The propeller with baffles will produce an axil flow pattern, Fig. 3, and the paddle and turbine will produce radial flow, Fig 4. 

It is interesting to note that the measurements of Price [7] now appear in a new light. Price devided the exit crossection of the packed bed into concentric circles and measured flow velocities within the radially shielded segments. By this method he suppressed the radial flow components above the bed and obtained profiles similar to the calculated ones (Figure 3 ). In particular Price also found the maximum very close to the wall. 

The heat transfer (cooling or heating) in a stirred vessel is achieved in a number of different ways. The most conventional method is the use of a coil heat exchanger. The nature and positioning of the coil depends on the nature of the flow pattern created by the stirrer. For an axial flow stirrer, a spiral coil (see Fig. 2a) is effective because it provides good liquid circulation between the coil and the wall. For radial flow stirrers, spiral coils deflect the liquid... 

An analysis of radial flow, fixed bed reactor (RFBR) is carried out to determine the effects of radial flow maldistribution and flow direction. Analytical criteria for optimum operation is established via a singular perturbation approach. It is shown that at high conversion an ideal flow profile always results in a higher yield irrespective of the reaction mechanism while dependence of conversion on flow direction is second order. The analysis then concentrates on the improvement of radial profile. Asymptotic solutions are obtained for the flow equations. They offer an optimum design method well suited for industrial application. Finally, all asymptotic results are verified by a numerical experience in a more sophisticated heterogeneous, two-dimensional cell model. 

The gas flow can have an axial, cross-flow or radial flow pattern. The different cooling methods can be combined in the same converter. 

In the radial heat-flow method the specimen is in the shape of a hollow cylinder, which is positioned in the annulus between two coaxial cylinders with the internal cylinder acting as a radial heat source. The temperature profile across the specimen is determined by thermocouples placed on the inside walls of the two cylinders. This method requires a large isothermal zone in the furnace, which is difficult to achieve at high temperatures. When this technique is used for measurements on liquids, errors can occur from convective heat transfer. 

Na O -h SiO. Susa et al —- (line source method) reported thermal conductivity data for solid and liquid slags for three compositions the single value obtained by Ogino et al l3 (radial heat-flow method) is in reasonable agreement with these data. 

The thermal conductivity values for polycrystalline (optically-thick) CaF obtained by. ngery —(comparative linear flow method) and by Taylor and Mills (laser pulse method) are in reasonable agreement (Figure 7). However, there is an appreciable discrepancy between the values of k obtained by the ziiQc source method —"— and the single value due to Ogino et al (radial heat source method). 

The use of annular cylindrical beds, fed through a central channel and drained at the periphery, is of potential interest in cases where high throughput rates and wide but shallow beds are desired. Radial-flow geometry is also characteristic of one operating method used in paper chromatography. 

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