BIO325H5 Lecture Notes - Lecture 4: Turbulence, Shear Rate, Trailing Edge
Document Summary
Retrograde body wave pushes back against the water; creating an accelerationreaction force (called normal force in this drawing). This is resolvable into two vectors: a side force" directed lateral to the direction of progress and thrust, directed straight forward. The magnitude of the reaction force is equal to the product of the acceleration given to the water and the mass of the water accelerated. The acceleration reaction force is perpendicular to the propulsive element and is inclined toward the head of the fish. Retrograde wave undulation of body and caudal fin one or more half wavelengths travel from its head to its tail at a speed greater than the fish"s speed with respect to the water. In the undulation each propulsive element moves laterally with respect to the head [accelerating] the water nearby. [axial] muscles accelerates the water; an equal opposing force, called the reaction force, is exerted on the propulsive element by the water.
