SUMMARY A computational fluid-dynamic analysis was conducted to study the unsteady aerodynamics of a model fruit fly wing. The wing performs an idealized flapping motion that emulates in normal hovering flight. Navier–Stokes equations are solved numerically. solution provides flow and pressure fields, from which aerodynamic forces vorticity wake structure obtained. Insights into force generation process gained flow-structure information. Considerable lift can be produced when majority...

SUMMARY The lift and power requirements for hovering flight in Drosophila virilis were studied using the method of computational fluid dynamics. Navier-Stokes equations solved numerically. solution provided flow velocity pressure fields, from which unsteady aerodynamic forces moments obtained. inertial torques due to acceleration wing mass computed analytically. On basis torques, For fruit fly (with symmetrical rotation), a midstroke angle attack approximately 37°was needed mean balance...

Because of their small size and flight regime, coupling aerodynamics, structural dynamics, dynamics are critical for micro aerial vehicles.This paper presents a computational framework simulating models varied fidelity Navier-Stokes solver, aimed at flapping flexible wings.The model uses either 1) the in-house developed UM/NLABS, which decomposes equations 3-D elasticity into crosssectional spanwise analyses slender wings, or 2) MSC.Marc, is commercial finite-element solver capable modeling...

Motivated by our interest in micro and biological air vehicles, Navier-Stokes simulations for fluid flow around a hovering elliptic airfoil have been conducted to investigate the effects of Reynolds number, reduced frequency, flapping kinematics on structure aerodynamics. The number investigated ranges from 75 1700, frequency 0.36 2.0. Two modes are studied, namely, water-treading mode, normal mode. Although delayed-stall mechanism is found be responsible generating maximum lift peaks both...

The study of atomic structure thiolate-protected gold with decreased core size is important to explore the structural evolution from Au(I) complex Au nanoclusters. In this work, we theoretically predicted recently synthesized four valence electron (4e) Au22(SR)18 cluster. cluster proposed possess a bitetrahedron Au7 kernel that surrounded by unique [Au6(SR)6] and three Au3(SR)4 staple motifs. More interestingly, exhibits connections Au24(SR)20 Au20(SR)16. stability can be understood...

For flight vehicles operated at the low Reynolds number regime, such as birds, bats, insects, well small man-made vehicles, flapping and fixed wings are employed in various ways to generate aerodynamic forces. wings, unsteady fluid physics, interacting with wing kinematics shapes determine lift generation. laminar-turbulent transition, three dimensional flows around aspect ratio coupling between flexible structures surrounding of major interest. In present paper we discuss recent progress...

Covalent organic frameworks (COFs) are promising iodine adsorbents. For improved performances, it is critical and essential to fundamentally understand the underlying mechanism. Here, using operando dark-field optical microscopy (DFM) imaging technique, observation of an extraordinary structure shrinkage 2D triphenylbenzene (TPB)-dimethoxyterephthaldehyde (DMTP)-COF upon adsorption I

Atomically precise thiolate-protected Au nanoclusters (NCs), i.e. Aum(SR)n, have attracted intensive research interest during the past few years. Recently, synthesis and isolation of selenolate-protected gold clusters (Aum(SeR)n) via ligand exchange thiolate with selenol were achieved, which demonstrated identical compositions to those NCs. In this study, we perform a comprehensive theoretical study on structure, electronic optical absorption properties 11 basis density functional theory...

The atomic structure of recently synthesized thiolate-protected Au76 cluster is theoretically predicted via a simple structural rule summarized from the crystal structures Au44(SR)28, Au36(SR)24, and Au52(SR)32 clusters. We find that Au76(SR)44 (N = 7) reported 4), Au44(SR)28 3), Au36(SR)24 2), Au28(SR)20 1) belong to family homologous Au20+8N(SR)16+4N clusters whose Au cores follow one-dimensional polytetrahedral growth pathway. contain an anisotropic face-centered-cubic (fcc) core, which...

Based on the characteristics of phase change concentrated heat, this article proposes a photovoltaic/phase change/thermoelectric (PV-PCM-TE) self-supply system with sidewall integrated TE. In system, an intelligent control circuit for time is designed to intelligently switch TE working mode using real-time temperature tracking. Therefore, material (PCM) delayed enhanced heat absorption and storage capacity, resulting in greater suppression PV rise. constant difference during change, more...

We report a systematic study of CO oxidation mechanism over nanoporous (NPG) using the density functional theory (DFT). In study, (111) and (100) flat planes that were identified as most abundant in gold are mimicked by Agx@Au-(111) Agx@Au-(100) slabs (x = 1 – 3). A total 50 reaction pathways examined at different active sites. simplified microkinetics model termed Sabatier analysis, which is built on adsorption energies activation barriers, used to evaluate rate pathways. Our theoretical...

Using the icosahedra M₁₃ (M = Au, Ag, Cu, Pt, Pd) and heteroatom doped Au₁₈M clusters as model systems, role of co-adsorbed CO molecule played in oxidation reaction is explored on basis density functional theory (DFT) calculations.

As the need for electric power grows continuously, transmission systems with more delivery capability, such as HVDC lines, are also needed. However, one of biggest obstacles to construct a new system is obtaining sufficient right-of-way, due mainly economical and ecological reasons. consequence, ac dc lines be built in parallel sharing same right-of-way. In this paper, electromagnetic interference line, capacitive inductive coupling from line close proximity, studied detail. A multiconductor...

The interaction between aerodynamics and structural flexibility in a low Reynolds number environment is of considerable interest to biological micro air vehicles. In this study, coupled fluid-structure computations the Navier-Stokes fluid flow flexible airfoil environments are conducted probe aerodynamic implications. While deforms response loading, it exhibits an equivalent pitching motion, which modifies effective angle attack, causing noticeable differences lift thrust generation. Within...

We propose Neural Cellular Automata (NCA) to simulate the microstructure development during solidification process in metals. Based on convolutional neural networks, NCA can learn essential features, such as preferred growth direction and competitive grain growth, are up six orders of magnitude faster than conventional (CA). Notably, delivers reliable predictions also outside their training range, which indicates that they physics process. While this study we employ data produced by CA for...

Abstract In this study, styrene‐ b ‐ethylene/butylene‐ ‐styrene triblock copolymer (SEBS) and maleic anhydride grafted SEBS (SEBS‐ g ‐MA) were used as compatibilizers for the blends of polyphenylene sulfide/nylon 66 (PPS/PA66). The mechanical properties, including impact tensile properties morphology blends, investigated by measurements scanning electron microscopy. Impact indicated that strength increases slowly with elastomer (SEBS SEBS‐ content upto 20 wt %; thereafter, it sharply...

Meltpool dimensions play a pivotal role in defining the defects and microstructure state of Laser Powder Bed Fusion (LPBF) builds. Therefore, it is crucial to investigate variations meltpool geometries under different process conditions. In this work, we fabricated single tracks LPBF Hastelloy X (HX) alloy 36 printing conditions examined corresponding cross-section at two locations across build platform. This investigation demonstrates impacts laser power, scan speed, powder layer thickness,...