Ship motions and drag reduction / [J.K. Lunde, Stanley W. Doroff, editors.]

Abstract

Since the Symposium on the Behavior of Ships in a Seaway (Wageningen, 1957), many papers have been published on the theory of ship motions.The present paper is a survey, collation, and evaluation of those contributions which have led toward a rational theory for predicting ship motions.During this period, evidence has accumulated which demonstrates the validity of the superposition principle for ship motions in a seaway. This concept was stated as hypothesis eleven years ago by St. Denis and Pierson (and also sixty years ago by R. E. Froude); its validity may now be considered as proven, beyond the fondest hopes of earlier investigators.With this principle established, attention once again returns to the prediction of motions in small-amplitude regular waves. The best practical approach to making ship motions predictions is probably still through use of strip theory. However, the two-dimensions assumptions 'A more precise definition is that p[aj<e(aj)<a2] -(a^-a^)/2TT. PROPERTIES OF TERMS IN THE EQUATIONS OF MOTIONThis chapter will be devoted to some special relationships for the various terms and coefficients in the eqviations of motion. Specifically, the following facts will be proven:1. The added mass matrix can be determined from the matrix of damping coefficients, and vice versa.