空気抵抗係数の異る粒子の均一分布

抄録

On the basis of the previously reported experiment in the measurment of the drag and lift coefficient of ellipsoidal seed particles, it is reported in this paper that the uniform distribution of the particles with different air drag-coefficients was wade by setting the duct with four nozzles on the spinner of the centrifugal distributor and making the particles with a large air drag-coefficient enlarge their flight distance by means of injecting air flow along the flight direction of particles.
1. The particles launched out show complicated flight trajectories affected by the air drag, the gravity and the lift. Although they are launched out under the same condition, yet their fallen location is distributed in a certain range of area depending upon difference of their flying orientation in the air.
2. The mean distance of flight and the diameter of distribution varies under the influence of the species of particle, the initial launching velocity and the initial velocity of injected air. This is shown in Fig. 4, 5 and 6.
3. When the pasture seed particles, red and ladino clovers, timothy and orchard grasses, are evenly scattered at one time, their mean distance of flight must be almost the same. When the clovers are emitted at the inital velocity of 10m/s and timothy and orchard at 10m/s to 50m/s (the emitted initial velocity in case of light particles gives little influence) in the initial velocity of 20-30m/s of injected air, the above result will be achieved and their meam distance of flight is about 4.0m.
4. However, as for the seed particles are almost similar in shape and nearly even in drage coefficient, yet extremely different in weight—for example orchard grass and osts—it is impossible to make them emit at the same distance, whatever emitting velocity and injected air velocity may be given to them.
5. Launched out particicles are scattered in the shape of lateral oval at the small injected air velocity, and in the shape of longitudinal ovel in the flight direction of particles at the great injected air velocity.
6. The particles fed at a point on the spinner are descended at the mean distance of flight with the highest probability. Their coefficient of distribution density is shown as i=i_maxe^-kr2. This is an approximate estimation.
7. The coefficient of the maximum distribution density is determind by the distribution area of particle, regardless the kind of species. It is shown in the following experical formula; i_max=9.42/D_x·D_z-0.106
8. With regard to unknown particles, their mean distance of flight and diameters of distribution can be estimated in reference to Fig. 4 to Fig. 6 using their known weight and shape as in Table 1. Their density of distribution can be determind by means of the formula 28 and 29. Moreover, the actual result of the density of distribution while driving on the field can be obtained by the intergration of area on diagram as shown in Fig. 14.On the basis of the previously reported experiment in the measurment of the drag and lift coefficient of ellipsoidal seed particles, it is reported in this paper that the uniform distribution of the particles with different air drag-coefficients was wade by setting the duct with four nozzles on the spinner of the centrifugal distributor and making the particles with a large air drag-coefficient enlarge their flight distance by means of injecting air flow along the flight direction of particles.
1. The particles launched out show complicated flight trajectories affected by the air drag, the gravity and the lift. Although they are launched out under the same condition, yet their fallen location is distributed in a certain range of area depending upon difference of their flying orientation in the air