Abstract
The resu'ts of model experiments of naked hull for the above case have been presented before this institution in 1920.
The present paper deals with the further investigation of the case for models with all appendages and also with propellers to find the effect of waves as well as propeller race of the leading model.
A short account of the apparatus used for “behind” experiment is given. The results obtained are :
(1) Wave making resistance of the following model is greatly affected by the distance, the maximum occurring at D/λ =0.85, 1.85, …, and the minimum at D/λ=1.35, 2.35, …, as in the case of naked hull. The propeller race of the leading model affects the resistance of the following model in similar way as waves produced by the leading one but in less significant degree.
(2) The number of revolutions of propeller, thrust deduction factor, &c. are affected by the speed as well as the distance of the models. The ratio of propeller revolutions of the two models seems to be represented by single curve for any speed and distance within the range experimented with, having maximum & minimum at 1.35 & 1.85 respectively.
(3) Finally it may be said that the following model is unstable to keep the distance constant when the model lies between the values of D/λ=1.351.85, and D/λ =2.352.85 and stable between D/λ =0.851.35 and D/λ=1.852.35.
