MEASUREMENT OF SHIP MODEL WAKE VARIATION IN ROUGH WATER, by

The object of this investigation was to devise instru-mentation for a small ship model to accurately measure the variables considered significant in the variation of wake velocity of a ship operating in rough water. It was hoped that by analysis of the results of tests at the M.I.T. Tow-ing Tank to show conclusively that wake variation for a model towed in ahead seas was caused by the orbital velocity of the water particles in the waves. To accurately fix the cause of wake variation, it was necessary to measure the motion of the model in the vicinity of the propeller location, and to locate the position of the wave crest at the times when the wake velocity was at its maximum and minimum points Results from the tests run were inconclusive as to th