PARAMETRIC AMPLIFICATION OF SURFACE AND INTERNAL WAVES.
Final scientific rept.,
MASSACHUSETTS INST OF TECH CAMBRIDGE FLUID DYNAMICS RESEARCH LAB
Pagination or Media Count:
The report concerns the possible amplification of waves in fluids due to fluctuations with time of some parameter which defines in part the natural frequencies of the system. Resonance is most likely to occur when some characteristic frequency is half of the frequency of parametric variation. First, the fluid is taken to be within a container which oscillates in the vertical direction so that the gravitational acceleration, relative to the container, varies with time. Both surface waves, in the case of an interface, and internal waves, in the case of continuous variation of density, are considered. In the latter case, the possible resonant frequencies have an upper bond. For an interface, rotation tends to eliminate the resonance of surface waves but to promote the resonance of inertial waves. For a continuous variation of density, rotation tends to place a lower bond on the possible resonant frequencies. Secondly, two fluids of different densities are taken to flow parallel to each other in an oscillatory manner and with different mean values of velocity. Author