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Flow Patterns of the paddle, the turbine and the propeller are intuitively said to be peripheral, radial and axial, respectively. Among them, the flow patters of a paddle type impeller were reported previously.1), 2) The introduction of the concept, "discharge rate of liquid from the turbine and the propeller", into the field of agitation, assimilating these impellers with those of turbine and propeller pumps, is considered to be helpful to the better understanding and simplification of the complicated phenomena, even apart, for the time being, from the concrete determination of interrelation between the "discharge rate" and the effect of mixing.
Since the direct application of many theoretical and practical analyses of pumps is apparently difficult in general, flow patterns of the turbine and the propeller impellers, together with the determination of power consumption, were studied, in this paper, following the same procedure as was described before1).
Prior to the experiment, theoretical considerations were given to the relationship between the power consumed and its flow pattern concerning the pitched paddle, for convenience sake. (See. Eqs. 1-10) Except for the introduction of lift, the way of reasoning is the same as was reported in the paper referred above.
Experiment
Flat blade turbines and a marine propeller together with its "modification" which were used in this series of experiments are described in Fig. 2, their specifications being tabulated in Table 1. Tank dimension and other experimental conditions (liquid: water) were the same as were described in the previous pape^r1).
Experimental Result and Discussion
Exemplifications of experimental results are shown in Figs. 3-5, concerning the turbine, the marine propeller and the "pitched paddle, " respectively. It is apparent from these figures that flow patterns of the turbine and the propeller are characterized as radial and axial, respectively, in the region adjacent to the impellers.
Analyses of these experimental results, whose procedures are exemplified in Tables 2 and 3 are plotted in Fig. 6. It is seen, in this figure, that the lift seems most powerful in the case of the marine propeller, with the tendency to decrease as the pitched angle θ0 approaches π/2.
Last of all, the estimation of discharge rate from the turbine was discussed. The discharge rate Q' as quoted in Fig. 7, relating to the flat blade turbine (nB=4) is the only data⁵⁾ ever published. However, the discharge rate Q which is defined in Eq. (11) may be different, in general, from Q' defined by Rushton et al. Therefore, by securing the data of power consumption of this flat blade turbine, (See Fig. 8), ω' was estimated by the trial and error method, using Fig. 6. And then, Q was calculated, using Eq. (12). Power was experimentally determined under the same experimental condition as was precisely described in the original paper⁵⁾.
On the other hand, using the vector angle at the blade periphery which is recorded in the paper⁵⁾, ω' was estimated and then, Q was computed, following the same procedure just mentioned above.
Comparison of Q, or ω' calculated through different procedures, …in short, ω' in the latter case…estimated by using the flow pattern data determined by optical observation, and that in the former case…estimated through the power determination and the use of Fig. 6 shows a good agreement in the range of the experimental condition.