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Published on: December 4, 2017
Fluid dynamics of moving fish in a two-dimensional multiparticle collision dynamics model
Daniel A P Reid1, H Hildenbrandt, J T Padding
1Behavioural Ecology & Self-organization & Theoretical Biology, Rijksuniversiteit Groningen, Nijenborgh 7, Groningen, The Netherlands.
This study uses multiparticle collision dynamics to model fish swimming, revealing thrust generation in the rear body and a negative correlation between slip ratio and efficiency. Results challenge previous theoretical predictions for undulating fish locomotion.
Area of Science:
- Fluid dynamics
- Biophysics
- Computational biology
Background:
- Studying animal locomotion fluid dynamics is challenging experimentally.
- Multiparticle collision dynamics (MPCD) offers a computationally efficient method for simulating fluid dynamics.
- Previous MPCD studies were limited to low Reynolds numbers and static or permeable shapes.
Purpose of the Study:
- To investigate the hydrodynamics of an undulating fish at higher Reynolds numbers (1100-1500) using MPCD.
- To analyze drag, thrust, lift, swimming efficiency, wake structure, and force distribution.
- To compare simulation results with empirical data and theoretical predictions.
Main Methods:
- Utilized the multiparticle collision dynamics (MPCD) method.
- Validated MPCD performance with a moving insect wing simulation at Reynolds number 75.
- Simulated an undulating fish model at Reynolds numbers 1100-1500.
Main Results:
- Confirmed resemblance between simulated and empirical fish locomotion data.
- Thrust is generated by the posterior two-thirds of the fish body, contrary to some theories.
- Observed a negative correlation between slip ratio (U/V) and Froude efficiency.
- Constraining sideways acceleration in models leads to artificial resemblance with unconstrained fish.
Conclusions:
- MPCD is suitable for studying fish hydrodynamics at higher Reynolds numbers.
- The study provides new insights into thrust generation and efficiency in undulating fish.
- Model constraints can significantly impact simulation outcomes, highlighting the need for careful model design.
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