【摘 要】
：
The variable flexibility of a fish body is believed to play a significant role in improving swimming performance.To explore the effect of non-uniform flexibility on the motion performance of fish under biologically relevant conditions,we set up three diff
【机 构】
：
School of Aircraft Engineering,Nanchang Hangkong University,Nanchang 330063,China
论文部分内容阅读
The variable flexibility of a fish body is believed to play a significant role in improving swimming performance.To explore the effect of non-uniform flexibility on the motion performance of fish under biologically relevant conditions,we set up three different flexible distribution modes for a semi-free filament and compared the motion performance of different flex-ible distribution modes through numerical simulations.The filament is located in the wake of the front flapping foil;it can swing adaptively in the lateral direction according to the flow situation of the surrounding fluid and finally reach a stable position.The results show that the motion state of the filament will alter with a change in the flexibility of the filament,from moving in the vortex street to moving on the side of the vortex street.In the Bénard-von Kármán (BvK) vortex streets,the drag coefficient of the filament increases as the flexibility of the filament increases,and the value of the drag coefficient is at a minimum when the flexibility of the filament increases linearly along the length of the filament.Further investigation indicates that at 85％-90％ of the filament length (starting from the leading edge),the flexibility of the filament begins to increase significantly,and the filament can obtain its best propulsion performance.The results of this work provide new insights into the role of non-uniform flexibility during the process of fish movement and provide a valuable reference for the design of bionic underwater vehicles.
其他文献
Excessive vibrations of railway vehicles induced by dynamic impact loadings have a significant impact on train operating safety and stability;however,due to the complexity and diversity of railway lines and service environment,they are extremely difficult
Implants,including artificial joints,bone fixation devices,and other orthopedic implants,oral implants,and vascular inter-ventional devices,are used to repair or replace human tissues or organs and restore their functions.Since biodegradable implants have
Self-assembled films (SAFs) have been proposed to be a promising candidate for molecularly thin lubricants.However,the frictional performance of SAFs is sensitively dependent on their molecular structures that are susceptible to external environments.Taki
The particle raft is a two-dimensional condensed soft matter,which is composed of hydrophobic solid particles floating on a liquid surface.In this study,we have realized to conduct tension and shear experiments on the particle raft by using the self-assem
Combustion phenomena were discovered still in far ancient time of China.From the 50\'s of the last century,owing to the fast development of energy and power,aeronautical and astronautical,chemical and metallurgical engineering,combustion theory started
A generalized analytical model is developed to predict progressive failure behavior of several types of textile composites,including plain weave composites,twill weave composites,two-dimensional tri-axially braided composites and warp-reinforced 2.5-dimen
Developments of soft network materials with rationally distributed wavy microstructures have enabled many promising appli-cations in bio-integrated electronic devices,due to their abilities to reproduce precisely nonlinear mechanical properties of human t
With appropriate stimuli,such as heat,humidity,or magnetic field,shape memory polymers (SMPs) can recover to their original shapes from temporary,programmed states.Using thermal responsive SMPs as substrates,we demonstrate a simple method to realize hybri
This paper investigates the flux-pinning-induced stress behaviors in a long superconducting slab with a central cuboid hole.The distribution of flux density is analytically derived for the critical current density of Kim model by considering the effects o
The evolution of the attitude angle and the mechanical energy exchange between the bus system and the solar sail via the con-necting wires are the main manifestations of the coupling dynamic effects on the orbit evolution,the attitude adjusting and the fl