Energy efficiency and propulsive characteristics of a 10 cm undulatory rainbow trout (oncorhynchus mykiss) swimming in a stationary position are considered. Two CFD simulations are performed utilizing dynamic grid meshing (FLUENT 6.3). The first simulation uses a laminar flow model with an added hydrofoil shape in order to test if thrust and drag can be brought to unity. The second simulation uses a Large-Eddy Simulation (LES) turbulence model to determine if transition to turbulence along the fish's surface leads to boundary layer separation. The expected results caused by adding these two features to earlier simulations do not occur. Thrust and drag are not found to be equal with usage of the thicker fish shape; instead both thrust and drag increase by 40-80% while diverging in value. Evidence of boundary layer separation is not present with usage of the LES turbulence model. Swimming energy efficiency is calculated to be 70% in both simulations. A brief analyses of boundary layer and downstream wake are included, showing general agreement with earlier studies. Limitations of the simulation are discussed. Future work regarding the author's preparation for an additional simulation of a rainbow trout utilizing a swimming method known as the Karman Gait is also considered. This preparation includes the creation of a 2-D grid domain and programs to define the kinematics of the fish and produce a specified vortex inlet condition.



College and Department

Ira A. Fulton College of Engineering and Technology; Civil and Environmental Engineering



Date Submitted


Document Type





hydrodynamics, fish, rainbow trout, turbulence, power efficiency, thrust, drag, marine propulsion