Current Research | Biomimetics

CFD and control coupling for numerical simulations on bio-inspired swimming robots

This numerical simulation is conducted in ANSYS Fluent 19.2 coupled with the in-house developed mobile multibody dynamics and control User Defined Function (UDF). The UDF enables the simulation of the dynamics and control of an unfixed multi body system connected by revolving joints and its FSI induced 6DoF (3DoF for 2D case) motion in the inertia frame.

A fluid-structure interaction study on a passively deformed fish fin

In this project, the propulsive performance of a caudal peduncle-fin swimmer mimicking a bio-inspired robotic fish model is numerically studied using a fully coupled FSI solver. The model consists of a rigid peduncle and a flexible fin which pitches in a uniform flow. The flexible fin is modelled as a thin plate assigned with non-uniformly distributed stiffness.

Multi-body Dynamics Modelling on a Self-propelled Pufferfish with Rigid Fins

In the present research, a self-propelled pufferfish with three rigid fins, i.e. caudal, dorsal and anal fins, is modelled with our in-house multi-body dynamics code. The model is extracted from a live fish experiment, which was tested at Shanghai Jiao Tong University (SJTU), China. The motion of the fish fins is also obtained from the experiment and the locomotion of the fish body is fully induced by the oscillating motion of fish fins and entirely determined by computation. Hydrodynamic forces are integrated using a Computational Fluid Dynamics method in the commercial software package Fluent.

Pharmaceutical Influences on Locomotion of Acquatic Animals by Experimental Measurements and Numerical Simulations

There are two types of muscles in most of the animals including zebra fish, one is called white muscle, which is responsible for the acceleration; another one is called red muscle that is responsible for sustainable low speed. As can be seen in Figure 1, muscle dystrophy will lead to the detachment of muscle fiber that is related to the swimming velocity of zebra fish. Besides, the change of muscle connections will have an influence on the energy transmission to the tail and causes different propulsion efficiency as well as other related parameters. Thus, in order to have a better understanding of the distribution of muscle dystrophy, a novel idea of analyzing forces and moments based on experimental measurements and numerical simulation via CFD software is provided for this interdisciplinary research.

Numerical Study of a Flapping Wing with a Torsion Spring

This is a case study for validation of passive joint part of in house code. The problem is a two-dimensional case, consisting of two elements that are connected with a given stiffness and damping ratio spring. Prescribed translational and rotational motion is added on the driven component. Passive component will be activated by the driven component through the spring.

Study of Zebrafish Behaviour Change under Various Environment Conditions

Zebrafish has become the most commonly used vertebrate model in biomedical research. In this study, we studied the change of zebrafish behaviour under various environment conditions.

Numerical Simulations on Bio-inspired Swimming Robots

This research is a numerical simulation, based on the bio-inspired swimming robots: the Amphibot III. There are eight segments in the model, representing the fish backbone from the head to the tail. The desired shape motion is defined before hand.

Numerical Simulations on an Articulated Fish-Like System

The research on fluid dynamics of biomimetic is a challenging problem due to the complex hydrodynamic mechanisms of real aquatic animals. Although there are existing investigations on the fish swimming mechanisms by establishing the numerical and experimental models with typical kinematic motions, the understandings are still limited on the fish body internal forces and response to external forces.

Response of a flexible filament in a flowing soap film subject to a forced vibration

In this work, we use a flexible filament as the flexible flag and soap film as a two dimensional flow to examine the dynamic response of the flexible filament to an externally imposed vibration at two initial states, i.e., a stretched-straight state and an oscillating state. Our main objective is to identify the frequency and amplitude relations between the external forced vibration and the filament�s dynamic response.

Three Dimensional Effects on the Translational Locomotion of a Passively Heaving Wing

Inspired by the novel flapping-wing mechanisms in nature flyers of insects, birds and bats, we have carried out a numerical study systematically investigating a three-dimensional flapping rigid wing with the passively actuated lateral and rotational motion. Distinguishing from the limited existing studies, our work performs a systematic examination on the effects of wing aspect ratio, inertia, torsional stiffness and pivot point on the dynamics response of a low aspect ratio rectangular wing under an initial zero speed flow field condition.

Parametric Study on a Cylinder Drag Reduction Using Downstream Undulating Foil

This study is a flow system with a D-sectional cylinder combined with an undulating NACA0012 foil in the wake of cylinder. Cylinder drag force could be considerably reduced if the foil is properly placed in the cylinder wake.