Inlet shape optimization of pneumobil engine pneumatic cylinder using CFD analysis

The aim of this study is to minimize minor losses in cap-end ports of a pneumatic cylinder used in pneumobil vehicle engine. Six geometry arrangements of intake ports,including the currently used version, were designed assuming conventional machining technology.Boundary conditions for the analysis were acquired from experimental measurement. The airflow was analyzed by 3D stationary CFD analysis in ANSYS Fluent for all designs. Pressuredrop was used as the evaluation criteria. Two best configurations according to the obtainedresults were optimized using ANSYS Fluent Adjoint Solver. The pressure drop was reducedby 81.1% using this method. The obtained results will be used for design of solid geometrycustomized for production by lost wax casting process

White paper on the future of plasma science and technology in plastics and textiles

International audienceThis white paper considers the future of plasma science and technology related to the manufacturing and modifications of plastics and textiles, summarizing existing efforts and the current state-of-art for major topics related to plasma processing techniques. It draws on the frontier of plasma technologies in order to see beyond and identify the grand challenges which we face in the following 5–10 years. To progress and move the frontier forward, the paper highlights the major enabling technologies and topics related to the design of surfaces, coatings and materials with nonequilibrium plasmas. The aim is to progress the field of plastics and textile production using advanced plasma processing as the key enabling technology which is environmentally friendly, cost-efficient, and offers high-speed processing

Lattice Topology Optimization in ANSYS software

ANSYS is one of the first commercially available software which allows to make topology optimization of lattice structures. In this bachelor’s thesis optimization workflow, calibration of numerical model, validation of numerical results and revelation of influence of basic parameters involved in computation – cell type, minimum and maximum relative density, cell size and used discretization, are showed. Optimised part was compared by means of FEM and homogenization with available experimental data. Subsequently, influence of basic parameters was evaluated. It was shown that optimized structure is stiffer than benchmark and influence of basic parameters for mechanical response and computational complexity was introduced. Simultaneously, it was shown that homogenization overestimated mechanical response. The findings of bachelor’s thesis validate computational model in program ANSYS and can be used for more effective making of optimization models

Topology optimisation using lattice structures

This thesis aimed to develop and verify the methodology for lattice topology optimization, which deals with additive manufacturing specifications and is independent of the optimization solver. The developed methodology uses the SIMP topology optimization algorithm. The penalization factor used for a solution is based on the mechanical properties characterizing arbitrarily chosen unit cell. These are identified using the homogenization method applied to the real geometry specified by 3D optical digitization. Verification is based on FEA using the variable homogenized properties. The local stress response is simulated by submodeling technique. The methodology was verified by optimizing the braking shield bracket of a plane. The optimized part is 22 % lighter and 31 % stiffer than the original solution. Results of the thesis demonstrate that the proposed methodology is suitable for structural part optimization and allows us to use lattice structures together with topology optimization and additive manufacturing relatively easily, not only in the space industry

Lattice Topology Optimization in ANSYS software

ANSYS je jeden z prvých komerčne dostupných softvérov, ktorý umožňuje vykonať topologickú optimalizáciu mikro-prútových štruktúr. V tejto bakalárskej práci je zobrazený postup optimalizácie, kalibrácia numerického modelu, validácia numerických výsledkov a určenie vplyvu základných parametrov, vstupujúcich do výpočtu – typu bunky, minimálnej a maximálnej relatívnej hustoty, veľkosti bunky a použitej diskretizácie. Optimalizovaný diel bol porovnaný pomocou MKP a homogenizácie s dostupnými experimentálnymi dátami. Následne bol vyhodnotený vplyv jednotlivých parametrov. Ukázalo sa, že optimalizovaná štruktúra je tuhšia ako v referenčnej štúdii a odhalený bol vplyv jednotlivých parametrov na mechanickú odozvu a časovú náročnosť výpočtu. Zároveň sa ukázalo, že metóda homogenizácie nadhodnotila mechanické vlastnosti. Výsledky bakalárskej práce validujú výpočtový model v programe ANSYS a môžu byť použité pre efektívnejšiu tvorbu optimalizačných modelov.ANSYS is one of the first commercially available software which allows to make topology optimization of lattice structures. In this bachelor’s thesis optimization workflow, calibration of numerical model, validation of numerical results and revelation of influence of basic parameters involved in computation – cell type, minimum and maximum relative density, cell size and used discretization, are showed. Optimised part was compared by means of FEM and homogenization with available experimental data. Subsequently, influence of basic parameters was evaluated. It was shown that optimized structure is stiffer than benchmark and influence of basic parameters for mechanical response and computational complexity was introduced. Simultaneously, it was shown that homogenization overestimated mechanical response. The findings of bachelor’s thesis validate computational model in program ANSYS and can be used for more effective making of optimization models.

Topology optimisation using lattice structures

Cieľom práce bolo navrhnúť a overiť metodiku topologickej optimalizácie s využitím mikro-prútových štruktúr, ktorá zohľadňuje špecifikácie aditívnej výroby a je nezávislá na optimalizačnom riešiči. Vytvorená metodika využíva SIMP algoritmus topologickej optimalizácie. Penalizačný faktor použitý pre riešenie je vytvorený na základe mechanických vlastností charakterizujúcich ľubovoľne zvolenú bunku. Vlastnosti sú získané metódou homogenizácie aplikovanou na reálnu geometriu špecifikovanú 3D optickou digitalizáciou. Verifikácia návrhu prebieha pomocou MKP analýzy využívajúcej variabilné homogenizované vlastnosti. Lokálna napätosť je simulovaná technikou submodelingu. Metodika bola overená optimalizáciou konzoly brzdného štítu lietadla. Optimalizovaný diel je oproti pôvodnému riešeniu o 22 % ľahší a o 31 % tuhší. Výsledky práce demonštrujú, že navrhnutá metodika je vhodná pre optimalizáciu štrukturálnych dielov a umožňuje nám relatívne jednoducho využiť mikro-prútové štruktúry spolu s topologickou optimalizáciou a aditívnou výrobou, a to nie len v leteckom priemysle.This thesis aimed to develop and verify the methodology for lattice topology optimization, which deals with additive manufacturing specifications and is independent of the optimization solver. The developed methodology uses the SIMP topology optimization algorithm. The penalization factor used for a solution is based on the mechanical properties characterizing arbitrarily chosen unit cell. These are identified using the homogenization method applied to the real geometry specified by 3D optical digitization. Verification is based on FEA using the variable homogenized properties. The local stress response is simulated by submodeling technique. The methodology was verified by optimizing the braking shield bracket of a plane. The optimized part is 22 % lighter and 31 % stiffer than the original solution. Results of the thesis demonstrate that the proposed methodology is suitable for structural part optimization and allows us to use lattice structures together with topology optimization and additive manufacturing relatively easily, not only in the space industry.

Two novel coordination polymers in the family of lanthanide complexes with o-phenylenedioxydiacetato as ligand

Two novel coordination polymers [Ce(PDOA)(NO3)(H2O)2]n (1) and {[Ce(PDOA)(NO3)(H2O)3]·H2O}n (2) (PDOA = o-phenylenedioxydiacetato) have been prepared using hydrothermal conditions and have been structurally characterized. In both crystal structures 1 and 2 the Ce(III) atoms are decacoordinated by oxygen atoms from PDOA ligands with chelating and bridging functions, chelating nitrato ligands and aqua ligands. While in 1 the PDOA ligand presents a hexadentate coordination mode, in 2 it is coordinated in a pentadentate manner; this difference leads to different types of one-dimensional structural motifs: in 2 there are zig-zag chains of the -Ce-O-C-O-Ce- type with syn-anti carboxylate bridges and in 1 these chains are additionally interlinked by further syn-anti carboxylate bridges leading to a strip- or ribbon-like arrangement formed of {Ce3} fused triangles. The endothermic dehydration of 1 within the temperature range 69-199 °C is at least a two-step process as suggested by TG and DTA methods. A variable temperature (2-300 K) magnetic study reveals Curie-Weiss behavior for 1 with θ = -35.5 K observed above 50 K. The origin of the observed behavior is discussed.This work was supported by the Slovak grants VEGA (grant No. 1/0075/13), APVV-0132–11 and APVV-0014-11. Funding from the Ministry of Science and Innovation (Spain) under grants MAT2011–27233-C02–1 and CONSOLIDER 25200 and from the Diputación General de Aragón is gratefully acknowledged. This publication is the result of the Project implementation: KVARK (ITMS: 26110230084), supported by the Research & Development Operational Program funded by the ESF.Peer Reviewe

Synthesis, crystal structure and magnetism of [Cu(cyclam)Ni(NCS)4(H2O)2]n

[Cu(cyclam)Ni(NCS)4(H2O)2]n (1) (cyclam = 1,4,8,11-tetraazacyclodecane) exhibits bent 1D crystal structure in which paramagnetic Cu(II) and Ni(II) atoms are linked by bridging μ2-NCS- ligands. The Cu(II) atom exhibit tetragonally elongated hexacoordination in the 4+2 form with one tetradentate macrocyclic cyclam ligands placed in the equatorial plane while the axial positions are occupied by S atoms from bridging NCS- ligands. The Ni(II) atom in NiN4O2 donor set is deformed octahedrally coordinated by four isothiocyanato ligands among which two in trans positions are bridging in nature; additional aqua ligands occupy the remaining two positions in trans arrangement. Weak hydrogen bonding interactions of the O-H···S type links the formed chains into 3D supramolecular structure. The magnetism of 1 is dominated by a sizable single-ion anisotropy DNi/hc = +7.49 cm-1 along with a weak exchange interaction of the ferromagnetic nature

Syntheses, crystal structure and magnetocaloric effect of [Gd(PDOA)(NO3)(H2O)2]n

The coordination polymer [Gd(PDOA)(NO)(HO)] (1) (PDOA = o-phenylenedioxydiacetato) has been prepared and spectroscopically and structurally characterized. Its crystal structure is formed of a ribbon-like arrangement of Gd(III) atoms linked by bridging carboxylate groups and placed at the cusps of fused triangles with Gd⋯Gd distances of about 6.1 Å. The Gd(III) central atoms exhibit decacoordination by oxygen atoms from hexadentate PDOA ligands with chelating and bridging functions, a chelating nitrato ligand and two aqua ligands. Intra- and intermolecular hydrogen bonds of the O[sbnd]H⋯O and C[sbnd]H⋯O types contribute to the stability of the structure. The temperature dependence of the magnetic susceptibility revealed weak magnetic interactions among Gd(III) ions which may be attributed to dipolar coupling. Investigation of the magnetocaloric effect gives an estimate of the maximum value of isothermal change of magnetic entropy –ΔS ≈ 35 J kg K which suggests that 1 can be a good material for magnetic cooling at low temperatures.This work was supported by the Slovak grants VEGA (grant No. 1/0063/17) and APVV-14-0073. We thank also the European Union Regional Development Fund (Slovakia) (ITMS: 26220120005) for financial support. Funding from the Spanish Ministry of Science and Innovation under grant MAT2015-68200-C2-1-P, from the European Regional Development Fund, and from the Diputación General de Aragón (E16) is gratefully acknowledged.Peer Reviewe

Synthesis, crystal structure and magnetic properties of (acetato-κ2O,O′)bis(5,5′-dimethyl-2,2′-bipyridine-κ2N,N′)nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5′-dmbpy)2]ClO4·H2O (where 5,5′-dmbpy is 5,5′-dimethyl-2,2′-bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′-dmbpy–KClO4 system. Within the complex cation, the NiII atom is hexacoordinated by two chelating 5,5′-dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen-bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single-ion anisotropy, D, which arises from the reduced local symmetry of the cis-NiO2N4 chromophore. The fitting of the variable-temperature magnetic data (2–300 K) gives giso = 2.134 and D/hc = 3.13 cm−1.This work was supported by the Slovak grant agencies VEGA (grant No. 1/0075/13) and APVV (grants No. APVV-0132-11 and APVV-0014-11). Funding from the Ministry of Science and Innovation (Spain) under grant MAT2011-27233-C02-01, from the Diputación General de Aragón, and from the European Union Regional Development Fund is gratefully acknowledged.Peer reviewe