i am a third year Btech student. i have completed construction of an ossilating water column with a bidirectional turbine. the model worked fine because the oscillations were created using a block piston. the frequency of the waves and thus the frequency of the air culumn oscillations were exagerated. but in the real environment, the frequency of the waves is not so high. please can some one give me an idea of a device which will act to increase the freq of the oscillating column by using the normal freq of the waves...