body design
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Author(s):  
Santanu Mitra ◽  
Vaibhav Sehgal ◽  
Shubham Rathore ◽  
Raghav Puri ◽  
Shivani Chouhan ◽  
...  

Biomimetics aims to take inspiration from nature and develop new models and efficient systems for a sustainable future. Bioinspired underwater robotics help develop future submarines that will navigate through the water using flexible propulsor. This research has focused on the Manta Ray species as batoid has a unique advantage over other species. This study also aims to improve AUV (Autonomous Underwater Vehicle) efficiency through biomimetic design, the purpose of which is to observe and study the marine environment, be it for sea exploration or navigation. The design and prototyping process of bioinspired AUVs have been mentioned in this study, along with testing a propulsive mechanism for efficient swimming and turning capabilities. The Robot was designed taking structural considerations from the actual Manta-Ray locomotion and body design. The propulsion mechanism and control circuit were then implemented on the developed systems. The prototype of the Manta Ray was able to generate a realistic swimming pattern and was tested in an acrylic tank. The experimental results obtained in the tank basin are very close to the results we observe in the real-world scenario in terms of the vehicle's forward and turning motion.


Zoomorphology ◽  
2021 ◽  
Author(s):  
Patrick Beckers ◽  
Carla Pein ◽  
Thomas Bartolomaeus

AbstractMushroom bodies are known from annelids and arthropods and were formerly assumed to argue for a close relationship of these two taxa. Since molecular phylogenies univocally show that both taxa belong to two different clades in the bilaterian tree, similarity must either result from convergent evolution or from transformation of an ancestral mushroom body. Any morphological differences in the ultrastructure and composition of mushroom bodies could thus indicate convergent evolution that results from similar functional constraints. We here study the ultrastructure of the mushroom bodies, the glomerular neuropil, glia-cells and the general anatomy of the nervous system in Sthenelais boa. The neuropil of the mushroom bodies is composed of densely packed, small diameter neurites that lack individual or clusterwise glia enwrapping. Neurites of other regions of the brain are much more prominent, are enwrapped by glia-cell processes and thus can be discriminated from the neuropil of the mushroom bodies. The same applies to the respective neuronal somata. The glomerular neuropil of insects and annelids is a region of higher synaptic activity that result in a spheroid appearance of these structures. However, while these structures are sharply delimited from the surrounding neuropil of the brain by glia enwrapping in insects, this is not the case in Sthenelais boa. Although superficially similar, there are anatomical differences in the arrangement of glia-cells in the mushroom bodies and the glomerular neuropil between insects and annelids. Hence, we suppose that the observed differences rather evolved convergently to solve similar functional constrains than by transforming an ancestral mushroom body design.


Author(s):  
Iuliia Pershyna

The paper examines methods for constructing mathematical models of two variables discontinuous functions using various information about them: one-sided values at points and one-sided traces along a given system of lines. The case is considered when the domain of the required function is triangulated by right-angled triangles. If interpolation or approximation methods are used, then for their construction the values of the function at given points must be given; if we use interlination methods, then traces of the desired function along a given system of lines. In this work, we construct a discontinuous interpolation and approximation splines for approximating a discontinuous function of two variables with given one-sided values in a given system of points (in our case, at the vertices of right-angled triangles), and prove theorems on the estimation of the approximation error by constructed discontinuous structures. In the paper a discontinuous interlination spline, which uses completely different information about the discontinuous function, namely one-sided traces along a given system of lines (in our case, along the sides of right-angled triangles) is also built. Interlination of functions can find wide application in the aircraft and automobile body design automation; when receiving and processing the results of sonar and radar, when solving problems of computed tomography, in digital signal processing and in many other areas. In the paper theorems on the integral form and an estimate of the approximation error by the constructed discontinuous interlination operator are also proved. Computational experiments that compare the results of the approximation of a discontinuous function of two variables by different information operators using triangular elements are presented. In the future, it is planned to apply the constructed operators of discontinuous approximation and interlination to solve a two-dimensional problem of computed tomography with a significant use of the inhomogeneity of the internal structure of the body, which must be reconstructed.


Aviation ◽  
2021 ◽  
Vol 25 (3) ◽  
pp. 202-210
Author(s):  
Nikolaos Kehayas

Induced drag constitutes approximately 40% of the total drag of subsonic civil transport aircraft at cruise conditions. Various types of winglets and several non-planar concepts, such as the C-wing, the joined wings, and the box plane, have been proposed for its reduction. Here, a new approach to induced drag reduction in the form of a combination of an elliptical and an astroid hypocycloid lift distribution is put forward. Lift is mainly generated from high circulation in the center part of the wing and fades away along the semi-span towards the wing tip. Using lifting line theory, the analysis shows that for fixed lift and wingspan the combined lift distribution results in an induced drag reduction of 50% with respect to the elliptical distribution. Due to its wing planform the combined lift distribution leads to a 51.5% higher aspect ratio. If structural constraints are placed, then the higher aspect ratio may affect wing weight. Although any substantial increase of wing weight is not envisaged, further study of the matter is required. Zero-lift drag and lift-dependent drag due to skin friction and viscosity-related pressure remain unaffected. The proposed lift distribution is particularly useful in a blended wing-body design.


Author(s):  
Ashutosh Kumar ◽  
◽  
Raghvendra Gautam ◽  

Objectives: To study a hybrid VTOL- Blended wing body design for its wings and elevons and perform CFD simulations with the wings. The steps for designing wing configuration and Elevon positioning involve different variables giving rise to a large number of design possibilities for a control surface. In the current study methods, have been proposed for the selection of optimized wing configuration and elevons positioning and validated with simulations model. Methods: Meta-heuristic methods like genetic algorithms are used for arriving at favorable solutions and Matlab coding is written for the initial draft of wing geometry, selected geometries are iterated in XFLR5 for stability and control, and later validated with simulations around the fluid domain. Elevons are control surfaces generally installed in tailless aircraft at the wing's trailing edge. It applies to roll and pitching force to wings as it combines the functionality of both pitching and rolling control. Design space was mathematically plotted and solved using MATLAB to decide elevons, wing configuration, and their positions.Findings: Initial selection of wing geometry, aoa, and structural design for maneuverability and stability for the enhanced aerodynamic performance of BWB UAV. In this presented paper drag coefficient of the designed BWB UAV comes out to be precisely around 0.02216 using computational modeling. Variation curve of Lift and drag coefficient with aspect ratio and angle of attack. Post-processing results of pressure forces and velocity profile on Wings accurately validate the proposed method of control surface optimization. Novelty: Designed BWB UAV has increased lift to drag ratio, reduced weight of airframe which improves performance. The Design phase is highly iterative, Through this research paper, an attempt has been made to develop a methodology for selection and investigation of control surfaces against requirements that makes BWB UAV more helpful for practical use and increasing the lift and endurance efficiency of the hybrid VTOL- Blended wing body aircraft.


Author(s):  
Danislav Drašković ◽  
Slobodan Tošić ◽  
Тomislav Vujinović

Pedestrians are a vulnerable group of traffic users who most often suffer serious physical injuries in collisions with motor vehicles, which very often have a fatal outcome. The modern automotive industry is investing great efforts in the development of active and passive protection systems for all traffic participants, including pedestrians. Pedestrian protection is tried to be achieved by changing the shape of the front parts of the vehicle, by using plastic materials with higher deformation potential which, in collision with the body of the pedestrian, will spend most of the impact energy on its own deformation and thus maximally spare the delicate biological tissue of the pedestrian. Instead of protruding, rigid metal structures of insignificant elasticity and deformation potential, today’s cars are characterized by appropriate body design, use of high elasticity materials and deformation of contact surfaces, specially shaped and integrated bumpers, elastic and raised bonnet, headlights integrated into the contour of the vehicle front which are capable of absorbing part of the impact energy. Modern research shows a certain efficiency of these improvements on modern cars. Most of these studies are of the experimental type and are done in strictly controlled conditions on dolls, often commissioned and funded by wealthy automobile corporations, while there is less research in real field conditions. Recently, experiments have been made with testing the active bonnet, the airbag under the bonnet, and the google model of gluing the pedestrian body.


2021 ◽  
Vol 4 (1(60)) ◽  
pp. 15-19
Author(s):  
Iryna Kazak

The article highlights one of the ways to improve the design of the extruder body in order to increase the reliability and, at the same time, the quality of extrusion. The object of research is a single-worm extruder. One of the most problematic areas of the extruder is the body. The main disadvantage of the extruder is the wear of the body surfaces due to corrosion or abrasion and requires regular replacement. This is due to the abrasive properties of the polymers and, accordingly, due to the friction of the polymer material against the body and the worm, especially due to contamination in the recycled material. In various sources, the replacement of the extruder worm with a more advanced design is widely covered. And scientists do not pay enough attention to improving the body of the extruder, which indicates the relevance of this study. That is why the problem of increasing the reliability of the extruder body is completely unsolved and urgent. In the course of the study, we used an analysis of the structural features of the extruder body, a literature-patent review of existing methods for improving the body of a single-worm extruder to increase the reliability and, at the same time, the quality of extrusion. As a result of the literature and patent review, the option of improving the extruder body based on the prototype of the split body, which additionally contains an inner surface of steel ribbed plates, was selected. It was found that the ribbing of the plates on the inner surface of the body increases the wear resistance of the body and promotes more intensive advancement of the polymer used material to the extruder head. This is due to the fact that the proposed improved body of the extruder has a number of features: steel ribbed plates rigidly fixed inside it are installed with overlap of the parting line of the extruder body. This makes it possible to increase the wear resistance and, accordingly, the reliability of the extruder body and, additionally, the extrusion quality. Compared with the known one-piece structures of the extruder body, the design of the body is detachable with steel rigidly mounted ribbed plates on the inner surface, which will simplify maintenance during repairs and, at the same time, improve the quality of extrusion.


2021 ◽  
Author(s):  
Michael Lau

Abstract OSIS-IHI (Ocean Structure Interaction Simulator – Ice-Hull Interaction) is a ship maneuvering in ice modeling software developed at OCRE for a marine simulator and ship performance assessment applications. A series of OSIS-IHI simulations is conducted to explain the maneuvering behavior observed of the USCGC Polar Icebreaker indicative design previously tested at the centre. The simulation is conducted with the original and a modified version of the USCGC Icebreaker Healy. The Icebreaker USCGC Healy was equipped with doublescrew conventional propellers. The hull geometry of the OSIS-Healy model is appropriately modified to mimic the hull form of two indicated design versions in question and its propulsion units replaced by twin pods prior to studying its maneuverability in order to shed light on the apparently poor maneuvering performance of the podded version of the indicative design. The modified version extends the mid-body leaving just 7.5 % of hull that constitutes the stern section. It is hypothesized that the extended mid-section cost large resisting moment against turning due to the increase of ice breaking at the aft shoulder and mid-body. This hypothesis is validated numerically to explain the poor maneuverability exhibited by the extended mid-body design, based on consideration of ice-hull interaction geometry and basic mechanics of ice breaking as well as existing anecdotal test evidences. This paper presents result of the simulation to explore effects of hull geometry and tightness of turns on ship maneuverability. Important insights gained are summarized and recommendation for further work given.


Author(s):  
Narjes Pourjafarian ◽  
Marion Koelle ◽  
Bruno Fruchard ◽  
Sahar Mavali ◽  
Konstantin Klamka ◽  
...  
Keyword(s):  

Author(s):  
Gozde Tuncer ◽  
Deniz Mansouri ◽  
Polat Şendur

Spotwelding and structural adhesive applications are two important processes in the automotive industry as they are closely associated with the functional requirements, weight, and cost of the vehicle. Even though there is a vast body of literature on their mathematical models, the effect of these processes on key vehicle performance indices and optimization is rather limited. Besides, the weight benefit of these processes in terms of functional requirements has not been investigated. There are multiple objectives of the paper to fill this gap: (i) to quantify the effect of structural adhesives on the key performance indices (KPIs) of a vehicle body, (ii) to rank the components based on their gauge sensitivities for body KPIs using topometry optimization, (iii) to assess the weight impact of the structural adhesive applications using the gauge sensitivity results, (iv) to determine the optimum layout of the structural adhesive applications using topology optimization, (v) to present a methodology for automotive original equipment manufacturers (OEMs) to determine the “critical welds” on the vehicle body and reduce the number of spotwelds as a potential cost reduction action. For this purpose, a validated finite element model of 2010 Toyota Yaris has been used. Optimization of the structural adhesives and spotwelds was carried-out using SIMP (Solid Isotropic Material with Penalization) based topology optimization. The thickness of each panel is ranked using topometry optimization results. Automotive OEMs can use the proposed methodology to optimize the structural adhesives or spotwelding processes in their product development cycle.


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