In relation to the behavior of fish school encountered by the leader-net, Fridman's theory is as follows. The fish school of constant concentration is considered as a liquid stream of density ρ=const. Let the volume rate of the liquid in the incoming stream to the leader-net be
q, the volume rates in the component of the same direction as yet which is parallel with the leader-net, and that of opposite side be q
2 and q
1, and the encounter angle be α, respectively,
i.e.,
q
1/q
2=(1-cosα)/(1+cosα).
The author has put forth a new theory on the behavior of the fish passing through the mesh of leader-net.
If the fish swimming speed when encountering the leader-net is ν, then the component of swimming speed in parallel with the leader-net is ν cosα, and that in right angle with the leader-net is ν sinα. The volume rate of the liquid passing through the mesh is q
3,
i.e.,
q1=k
1k
1•sinα/2
q
2=k
2•(sinα/2+cosα)
q
3=k
3•sinα
k
1, k
2, k
3; const.
This theory is more in conformity with the experimental values than Fridman's.
抄録全体を表示