飛行艇の離着水運動

Since full-scale experiments on the motion of a flying boat during take-off and landing run has rarely been under-taken so far, there is uncertainty as to whether or not the water resistance, trim, heaving and hump speed as measured in tank experiments are in agreement with actual conditions. In this experiment the motion of "N" and "Dornier Wal" flying boats-the lines being shown in Figs. 5 and 6-was measured photogrametrically, by the method described in the author's earlier report. The trim and heaving were read off directly from the film. The water resistance H was obtained from the relations: H=S-G/ga-W for take-off run, and H=G/ga-W for landing run, where S=Thrust, calculated from the thrust coefficient for "N", and calculated on the basis of the empirical formulae for Wal, G/g=Mass of the aeroplane, a=Acceleration, obtained from graphical differenciation of the timedistance curve, W=Air resistance. The results are shown in Tables and Figs, as follows: [table] The coefficients of water resistance, the trim and heaving for each take-cff run are shown in Fig. 25, and those for landing run in Fig. 26. For comparison, the coefficients obtained from tank experiments are also shown (see Fig. 25). The conclusion is that: (1) The water resistance curve obtained from the take-off run of the actual flying boats has about the same value at its maximum point as that obtained from the tank experiment. (2) The water resistance curve for the take-off run of "N" flying boat has two humps, the first hump speed being smaller than that obtained in the tank experiments. (3) For speeds greater than the hump speed the water resistance is much less than that expected from the results of tank experiments. (4) The water resistance curve for the landing run differs considerably from that for the take-off run. (5) The hump speed is less for flat bottom ("Dornier Wal") than for Vee bottom ("N") flying boat. (6) The trim angle is almost constant for the planing stage. (7) The heaving curves for both the full-scale and the tank experiment show fair agreement.

資料番号: SA4148265000