Hydrodynamic Analysis for the Morphing Median Fins of Tuna during Yaw Motions

Applied Bionics and Biomechanics ◽

10.1155/2021/6630839 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Xiaohu Li

Keyword(s):

Numerical Method ◽

Hydrodynamic Forces ◽

The Body ◽

Robotic Fish ◽

Hydrodynamic Performance ◽

Hydrodynamic Analysis ◽

Dorsal Fin ◽

The Stability ◽

Median Fins

Tuna can change the area and shape of the median fins, including the first dorsal, second dorsal, and anal fins. The morphing median fins have the ability of adjusting the hydrodynamic forces, thereby affecting the yaw mobility of tuna to a certain extent. In this paper, the hydrodynamic analysis of the median fins under different morphing states is carried out by the numerical method, so as to clarify the influence of the erected median fins on the yaw maneuvers. By comparing the two morphing states of erected and depressed, it can be concluded that the erected median fins can increase their own hydrodynamic forces during the yaw movement. However, the second dorsal and anal fins have limited influence on the yaw maneuverability, and they tend to maintain the stability of tuna. The first dorsal fin has more lift increment in the erection state, which can obviously affect the hydrodynamic performance of tuna. Moreover, as the median fins are erected, the hydrodynamic forces of the tuna’s body increase synchronously due to the interaction between the body and the median fins, which is also very beneficial to the yaw motion. This study indicates that tuna can use the morphing median fins to adjust its mobility and stability, which provides a new idea for the design of robotic fish.

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Tuna locomotion: a computational hydrodynamic analysis of finlet function

Journal of The Royal Society Interface ◽

10.1098/rsif.2019.0590 ◽

2020 ◽

Vol 17 (165) ◽

pp. 20190590 ◽

Cited By ~ 7

Author(s):

Junshi Wang ◽

Dylan K. Wainwright ◽

Royce E. Lindengren ◽

George V. Lauder ◽

Haibo Dong

Keyword(s):

High Speed ◽

Cross Flow ◽

The Body ◽

Hydrodynamic Performance ◽

Thunnus Albacares ◽

Hydrodynamic Analysis ◽

Kinematic Data ◽

Hydrodynamic Function ◽

Scombrid Fishes

Finlets are a series of small non-retractable fins common to scombrid fishes (mackerels, bonitos and tunas), which are known for their high swimming speed. It is hypothesized that these small fins could potentially affect propulsive performance. Here, we combine experimental and computational approaches to investigate the hydrodynamics of finlets in yellowfin tuna ( Thunnus albacares ) during steady swimming. High-speed videos were obtained to provide kinematic data on the in vivo motion of finlets. High-fidelity simulations were then carried out to examine the hydrodynamic performance and vortex dynamics of a biologically realistic multiple-finlet model with reconstructed kinematics. It was found that finlets undergo both heaving and pitching motion and are delayed in phase from anterior to posterior along the body. Simulation results show that finlets were drag producing and did not produce thrust. The interactions among finlets helped reduce total finlet drag by 21.5%. Pitching motions of finlets helped reduce the power consumed by finlets during swimming by 20.8% compared with non-pitching finlets. Moreover, the pitching finlets created constructive forces to facilitate posterior body flapping. Wake dynamics analysis revealed a unique vortex tube matrix structure and cross-flow streams redirected by the pitching finlets, which supports their hydrodynamic function in scombrid fishes. Limitations on modelling and the generality of results are also discussed.

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THE CHARACTERISTICS OF ARTIFICIAL RICE WITH SEAWEED Eucheuma cottonii ADDITION AS A DIETARY FIBER SOURCE

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.29244/jitkt.v6i1.8641 ◽

2014 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Natalia Prodiana Setiawati ◽

Joko Santoso ◽

Sri Purwaningsih

Keyword(s):

Blood Glucose ◽

Dietary Fiber ◽

Dietary Fibre ◽

Extrusion Process ◽

The Body ◽

Starch Digestibility ◽

Food Commodities ◽

The Stability ◽

Extrusion Technology ◽

Eucheuma Cottonii

The utilization of local food commodities such as corn and cassava with seaweed addition as a dietary fiber source for producing artificial rice through extrusion technology is an alternative for food diversification. The research was carried out to find out the best composition (rice, corn, cassava, and seaweed) and temperature of extrusion process on making artificial rice and the influence of dietary fibre on sensory properties and physicochemical. The composition of rice, corn, and cassava in proportion of 1:3:1 with 20% seaweed, Eucheuma cottonii, addition and temperature extruder of 90 °C were selected as the best product for artificial rice. The sensory evaluation was 8.02±0.21 (people’s preference). In physicochemical properties, dietary fiber significantly affected on low bulk density and starch digestibility. This condition is very good for health especially in maintaining the stability of blood glucose in the body. Keywords: artificial rice, composition, extrusion, seaweed, dietary fibre, temperature

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Substantiation the machine with a basket for the application of mineral fertilizers and other bulk materials with the upper arrangement of the feeding device

Mehanization and electrification of agricultural ◽

10.37204/0131-2189-2019-9-4 ◽

2019 ◽

pp. 37-43

Author(s):

Fesenko, H.

Keyword(s):

Fat Body ◽

Mineral Fertilizer ◽

The Body ◽

Mineral Fertilizers ◽

Analytical Mechanics ◽

Bulk Materials ◽

The Stability ◽

Working Bodies ◽

The Relationship ◽

Stable Flow

Purpose. Increasing the uniformity of distribution of mineral fertilizers and other bulk materials due to the stability of their feed from the body to the spreading working bodies using the top feeder. Methods. The following methods are used to achieve this aim: the method of comparing the differences between individual groups of fertilizers, the method of analyzing the properties of a new technical system, the method of functional inventiveness, and the methods of theoretical and analytical mechanics. Results. The traction body of the conveyor of the upper feed of the body fat body machine for mineral fertilizers and other bulk materials was substantiated and the relationship between the height of its scrapers and the distance between them was established, as well as the nature of the mineral fertilizer pressure on the curvilinear wall of the body. In addition, the design of the advanced body fertilizer spreader is justified, which ensures a stable flow of fertilizers from the body due to the improvement of the top feeder. Conclusions. Because of the conducted researches, the advantages of machines equipped with top feeder are found. They create the conditions for the forced feeding mineral fertilizers and other loose materials from the container to the distribution bodies, which is a prerequisite for their evenness on the surface. With this, the imperfection of known machines with the top feeder constrains their introduction into agricultural production. On this account, a more thoroughly constructed solution of the body feeder of the top feed is substantiated, in which the conveyor provides a stable supply of fertilizers from the body with reduced energy consumption during operation. Keywords: analysis, feed, upper device, conveyor, stability, fertilizers, flow ability, body.

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Novel Nanolipoidal Systems for the Management of Skin Cancer

Recent Patents on Drug Delivery & Formulation ◽

10.2174/1872211314666200817115700 ◽

2020 ◽

Vol 14 (2) ◽

pp. 108-125

Author(s):

Apoorva Singh ◽

Nimisha

Keyword(s):

Skin Cancer ◽

Survival Rates ◽

Cancer Therapeutics ◽

The Body ◽

Surgical Removal ◽

The Novel ◽

Skin Cancers ◽

Recent Developments ◽

Abnormal Cells ◽

The Stability

: Skin cancer, among the various kinds of cancers, is a type that emerges from skin due to the growth of abnormal cells. These cells are capable of spreading and invading the other parts of the body. The occurrence of non-melanoma and melanoma, which are the major types of skin cancers, has increased over the past decades. Exposure to ultraviolet radiations (UV) is the main associative cause of skin cancer. UV exposure can inactivate tumor suppressor genes while activating various oncogenes. The conventional techniques like surgical removal, chemotherapy and radiation therapy lack the potential for targeting cancer cells and harm the normal cells. However, the novel therapeutics show promising improvements in the effectiveness of treatment, survival rates and better quality of life for patients. Different methodologies are involved in the skin cancer therapeutics for delivering the active ingredients to the target sites. Nano carriers are very efficient as they have the ability to improve the stability of drugs and further enhance their penetration into the tumor cells. The recent developments and research in nanotechnology have entitled several targeting and therapeutic agents to be incorporated into nanoparticles for an enhancive treatment of skin cancer. To protect the research works in the field of nanolipoidal systems various patents have been introduced. Some of the patents acknowledge responsive liposomes for specific targeting, nanocarriers for the delivery or co-delivery of chemotherapeutics, nucleic acids as well as photosensitizers. Further recent patents on the novel delivery systems have also been included here.

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Polymer-Drug Conjugates as Nanotheranostic Agents

Journal of Nanotheranostics ◽

10.3390/jnt2010005 ◽

2021 ◽

Vol 2 (1) ◽

pp. 63-81

Author(s):

Sajana Manandhar ◽

Erica Sjöholm ◽

Johan Bobacka ◽

Jessica M. Rosenholm ◽

Kuldeep K. Bansal

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Treatment Options ◽

The Body ◽

Drug Conjugates ◽

Imaging Characteristics ◽

Wide Range ◽

Systemic Side Effects ◽

Theranostic Agents ◽

The Stability

Since the last decade, the polymer-drug conjugate (PDC) approach has emerged as one of the most promising drug-delivery technologies owing to several benefits like circumventing premature drug release, offering controlled and targeted drug delivery, improving the stability, safety, and kinetics of conjugated drugs, and so forth. In recent years, PDC technology has advanced with the objective to further enhance the treatment outcomes by integrating nanotechnology and multifunctional characteristics into these systems. One such development is the ability of PDCs to act as theranostic agents, permitting simultaneous diagnosis and treatment options. Theranostic nanocarriers offer the opportunity to track the distribution of PDCs within the body and help to localize the diseased site. This characteristic is of particular interest, especially among those therapeutic approaches where external stimuli are supposed to be applied for abrupt drug release at the target site for localized delivery to avoid systemic side effects (e.g., Visudyne®). Thus, with the help of this review article, we are presenting the most recent updates in the domain of PDCs as nanotheranostic agents. Different methodologies utilized to design PDCs along with imaging characteristics and their applicability in a wide range of diseases, have been summarized in this article.

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A novel numerical method for the hydrodynamic analysis of floating bodies over a sloping bottom

Journal of Marine Science and Technology ◽

10.1007/s00773-020-00795-6 ◽

2021 ◽

Author(s):

Xiaolei Liu ◽

Quanming Miao ◽

Xuefeng Wang ◽

Shengwen Xu ◽

Huiqu Fan

Keyword(s):

Numerical Method ◽

Floating Bodies ◽

Hydrodynamic Analysis ◽

Sloping Bottom

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Machine learning-based performance analysis of two-axial-groove hydrodynamic journal bearings

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650121992895 ◽

2021 ◽

pp. 135065012199289

Author(s):

Biswajit Roy ◽

Sudip Dey

Keyword(s):

Journal Bearing ◽

Journal Bearings ◽

Hydrodynamic Performance ◽

Support Vector ◽

Oil Viscosity ◽

Hydrodynamic Analysis ◽

Supply Pressure ◽

Input Parameters ◽

Precise Prediction ◽

Output Behavior

The precise prediction of a rotor against instability is needed for avoiding the degradation or failure of the system’s performance due to the parametric variabilities of a bearing system. In general, the design of the journal bearing is framed based on the deterministic theoretical analysis. To map the precise prediction of hydrodynamic performance, it is needed to include the uncertain effect of input parameters on the output behavior of the journal bearing. This paper presents the uncertain hydrodynamic analysis of a two-axial-groove journal bearing including randomness in bearing oil viscosity and supply pressure. To simulate the uncertainty in the input parameters, the Monte Carlo simulation is carried out. A support vector machine is employed as a metamodel to increase the computational efficiency. Both individual and compound effects of uncertainties in the input parameters are studied to quantify their effect on the steady-state and dynamic characteristics of the bearing.

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Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves

Journal of The Royal Society Interface ◽

10.1098/rsif.2016.0068 ◽

2016 ◽

Vol 13 (116) ◽

pp. 20160068 ◽

Cited By ~ 16

Author(s):

Gen Li ◽

Ulrike K. Müller ◽

Johan L. van Leeuwen ◽

Hao Liu

Keyword(s):

Larval Fish ◽

Fish Larvae ◽

Fluid Dynamic ◽

Three Dimensional ◽

Reynolds Numbers ◽

Bony Fish ◽

The Body ◽

Functional Explanation ◽

Image Velocimetry ◽

Median Fins

Larvae of bony fish swim in the intermediate Reynolds number ( Re ) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left–right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae.

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An Efficient Galerkin BEM to Compute High Acoustic Eigenfrequencies

Journal of Vibration and Acoustics ◽

10.1115/1.3085894 ◽

2009 ◽

Vol 131 (3) ◽

Cited By ~ 9

Author(s):

Mario Durán ◽

Jean-Claude Nédélec ◽

Sebastián Ossandón

Keyword(s):

Numerical Method ◽

Integral Equations ◽

High Frequency ◽

High Accuracy ◽

Integral Representations ◽

Stability And Convergence ◽

Symmetric Matrices ◽

Frequency Interval ◽

Numerical Treatment ◽

The Stability

An efficient numerical method, using integral equations, is developed to calculate precisely the acoustic eigenfrequencies and their associated eigenvectors, located in a given high frequency interval. It is currently known that the real symmetric matrices are well adapted to numerical treatment. However, we show that this is not the case when using integral representations to determine with high accuracy the spectrum of elliptic, and other related operators. Functions are evaluated only in the boundary of the domain, so very fine discretizations may be chosen to obtain high eigenfrequencies. We discuss the stability and convergence of the proposed method. Finally we show some examples.

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