Falling Behavior of Fish Nursery Blocks in Water

Abstract

This study aims to develop an accurate placement method of fish nursery blocks utilizing free fall in the deep sea area. Falling behavior of concrete blocks in water was investigated by the hydraulic model tests and numerical simulations. As a result, a new nursery block shape which falls through water with highly stable behavior was developed. The validity of the numerical simulation method was confirmed by model tests. In addition, an quick estimable system on the placement position and the probability distribution on the sea bottom was also developed. In the system, the average placement position is calculated from hydrodynamic force calculations based on the hydrodynamic force coefficients. The probability distribution of the placement positions is predicted by applying Markov chain theory.