On a rectangular pressure distribution of oscillating strength moving over a free surface
Abstract
Through the application of linearized waterwave theory, a solution of the free surface due to the disturbance of a moving, oscillatory pressure distribution of rectangular form is obtained. Such a solution provides the basis for formulating the wave resistance of the moving pressure distribution just cited, as well as the hydrodynamic coefficients of a capturedair bubble of rectangular footprint in heave motion. Numerical methods are developed to compute the aforementioned resistance and hydrodynamic coefficients, the numerical examples of which are also presented. Of special interest is the occurrence of negative effective mass at low frequencies for the two forward speeds considered in the present work. Another interesting feature is the hydrodynamic instability and the negative damping that occurs in the lowfrequency range when the Froude number is very high.
 Publication:

Journal of Ship Research
 Pub Date:
 March 1977
 Bibcode:
 1977JShR...21...11C
 Keywords:

 Captured Air Bubble Vehicles;
 Oscillating Flow;
 Pressure Distribution;
 Water Waves;
 Froude Number;
 Hydrodynamic Equations;
 Linear Systems;
 Numerical Analysis;
 Potential Flow;
 Rectangular Planforms;
 Velocity Distribution;
 Wave Resistance;
 Fluid Mechanics and Heat Transfer