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1

Propulsion System Analysis Based on Particle Image Velocimetry Method in Biomimetic Unmanned Underwater Vehicle

Piskur Paweł

Pomiary Automatyka Robotyka

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2022

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R. 26, nr 3

23--27

EN

The article presents a laboratory stand for direct measurement of the thrust generated by the undulating propulsion system of a biomimetic underwater vehicle. The laboratory water tunnel enables research and comparison of the generated thrust with the results of the fin and fluid interaction analysis using the Particle Image Velocimetry method. The water tunnel is equipped with an industrial camera for recording changes in the position of markers highlighted with a line laser in the area of analysis. The comparison of the results obtained by the PIV method with the industrial force sensor allows for the analysis of the efficiency of the biomimetic propulsion system as a function of both design and control parameters.

PL

W artykule przedstawiono stanowisko laboratoryjne do bezpośredniego pomiaru naporu generowanego przez napęd falowy biomimetycznego pojazdu podwodnego. Stanowisko umożliwia przeprowadzenie badań i porównanie generowanego naporu z wynikami analizy interakcji płetwy i płynu z wykorzystaniem metody PIV. Stanowisko wyposażone jest w kamerę przemysłową do rejestrowania zmiany położenia markerów podświetlonych liniowym laserem w obszarze analizy. Porównanie wyników uzyskanych metodą PIV z przemysłowym czujnikiem siły pozwala na analizę sprawności biomimetycznego układu napędowego w funkcji zarówno parametrów konstrukcyjnych jak i sterujących.

2

Patient-specific fluid-structure interaction simulation of the LAD-ITA bypass graft for moderate and severe stenosis: A doubt on the fractional flow reserve-based decision

Tajeddini Farshad, Firoozabadi Bahar, Pakravan Hossein Ali, Ahmadi Tafti Seyed Hossein

Biocybernetics and Biomedical Engineering

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2022

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Vol. 42, no. 1

143--157

EN

Fractional flow reserve (FFR)-based decision improves the outcomes of percutaneous coronary intervention (PCI) for some patients, while its effectiveness in improving the results of coronary artery bypass graft (CABG) is unclear, in particular for moderate stenosis. It may be due to the fact that FFR cannot take into account the impacts of competitive flow (CF), intimal hyperplasia (IH), as well as compliance mismatch (CMM). As a result, two questions arise 1) whether FFR is a sufficient factor to decide to perform the CABG for patients with moderate to severe stenosis or not and 2) whether post-operative FFR shows the effectiveness of a graft. To shed light on this matter, two patient-specific models of LAD-ITA graft, consisting of two different severities of stenosis (moderate and severe), were simulated using two-way FSI simulation. It was observed that although both pre- and postoperative FFRs for moderate stenosis were higher, CF is more intense for moderate stenosis than severe one. Also, it was seen that CM and IH are more likely to occur in the bed, toe, and heel areas of a bypass graft performed for moderate stenosis. All in all, it can be concluded that in the case of moderate stenosis, pre- and post-operative FFRs might not be a suitable index for making the decision about performing or deferring CABG and also the effectiveness of the graft. Under such circumstances, it seems rational to use CFD in a wider range to investigate patients with moderate stenosis before the operation.

3

Fuel saving index assessment on driving behavior control system of prototype model using neural network

Munahar Suroto, Triwiyatno Aris, Munadi M., Setiavan Joga Dharma

Archives of Transport

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2022

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Vol. 63, iss. 3

123--141

EN

Efficient fuel consumption in the world is essential in automotive technology development due to the increase in vehicle usage and the decrease in global oil production. Several studies have been conducted to increase fuel consumption savings, Fuel Cells (FCs), the application of alternative energy vehicles and the Engine Control Unit (ECU) system. FCs do not require oil energy to propel the vehicle, so this technology promises to reduce energy consumption and emissions. However, this research still leaves problems. FCs are susceptible to short circuit hazards, and ownership costs are very high. Alternative energy applications produce less power, less responsive acceleration, and insufficient energy sources to enter mass production. The ECU application still has an orientation toward achieving stoichiometry values, so the increase in fuel efficiency has the potential to be improved. Driving behavior is a variable that has a close relationship with fuel consumption efficiency. However, research on driving behavior is only studied for implementation in autonomous car-following technologies, safety systems, charging needs characteristic of electric vehicles, emission controls, and display images on invehicle information systems. Meanwhile, research on driving behavior as a control system to improve fuel efficiency has not been carried out. To that end, this study proposes the use of driving behavior for a newly designed control system to improve fuel efficiency. The control system in this research is a prototype model to be assessed using the Fuel Saving Index (FSI) analysis. An artificial neural network is used to help the recognition of driving behavior. The results showed that the newly designed control system was categorized on scale IV of FSI. On this scale, the power generated by the engine is quite optimal when it is in the eco-scheme driving behavior. The driving behavior control system can significantly improve the efficiency of fuel consumption. Air to Fuel Ratio (AFR) is achieved above the stoichiometric value.

4

Influence of the elastic cavity walls on cavity flow noise

Łojek Paweł, Czajka Ireneusz, Gołaś Andrzej, Suder-Dębska Katarzyna

Vibrations in Physical Systems

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2021

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Vol. 32, nr 1

art. no. 2021109

EN

In this study, computational fluid dynamics and computational aeroacoustics methods were used to investigate the influence of the elastic cavity walls on the noise generated by the flow over rectangular cavity. Two cases were considered and compared, one with rigid cavity walls, and one with elastic walls. In the latter case, the movement of the walls were solved by finite element modelling and coupled with CFD simulations. The noise generated by the flow over cavity was computed using Ffowcs Williams & Hawkings acoustic analogy. The increase of the sound pressure level for elastic walls case at frequency range of 1 kHz to 10 kHz is observed, compared to the rigid walls case.

5

Numerical simulations of the flows past rotating geometries

Simon Jakub, Stankiewicz Witold

Vibrations in Physical Systems

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2020

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Vol. 31, nr 3

art. no. 2020318

EN

In the present paper the numerical approach for the modeling of the flow past rotating geometries is presented. Practical methods for two cases are described: the one where whole domain is moving with uniform angular velocity, where the rotation might be included in the governing equations only (in the terms related to Coriolis and centrifugal forces), and the one where part of the domain is rotating, whereas another one is stationary. The second case is illustrated by examples describing the steady and transient flow around a rotating propeller and by a centrifugal pump. Simulations are performed using OpenFOAM CFD solver, with the models covering flow rotation: MRF (multiple reference frame) and AMI (arbitrary mesh interface).

6

Finite element-finite volume simulation of underwater explosion and its impact on a reinforced steel plate

Valdani Arman Jafari, Adamian Armen

Archive of Mechanical Engineering

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2020

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LXVII, nr 1

5--30

EN

Marine structures are one of the most important industrial and military equipment in each country that should be protected against external forces. The main aim of this paper is a detailed investigation of the underwater explosion (UNDEX) and its effects on marine structures. For this purpose, the UNDEX structure was studied qualitatively and quantitatively using numerical methods. Then, the effects of blast waves on a marine structure reinforced by perpendicular blades were investigated. Finite element and finite volume schemes were used for discretization of the governing equations in the solid and fluid media, respectively. Also, for fluid-structure interaction (FSI), results of fluid and solid media were mapped to each other using the two-way FSI coupling methods. A comparison of numerical results with the empirical formula revealed that the trend of pressure-time curves was reasonable, approving the validity of the numerical method. Moreover, the numerical results indicated that detonation of 1 kg trinitrotoluene (TNT) creates a pressure wave with maximum amplitude of 24 MPa at a distance of 2 m. Also, it was found that the reinforcement blades can be used to improve the resistance of structures against explosive charges, which also results in the reduction of structures deformation.

7

Simulations of safety vales for fluid power systems

Domagała Mariusz, Momeni Hassan, Fabiś-Domagała Joanna, Filo Grzegorz, Lempa Paweł

System Safety : Human - Technical Facility - Environment

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2019

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Vol. 1, nr 1

670--677

EN

Hydraulic power systems are widely used in heavy machinery. Safety of such a systems have a major importance due to the fact that any failure may cause environmental contamination or serious injury. One of the component which protects hydraulic drive systems against excessive rising of working pressure is a safety valve which aim is to maintain pressure in the systems below acceptable level. Pressure control valves which plays important role in a hydraulic systems may have very simple or complex structure. Even in case of the simplest structure of such valve modeling is not an easy task. The new quality in designing hydraulic valves bring CFD method and FSI (Fluid Structure Interaction) methods.

8

Model order reduction technique applied on harmonic analysis of a submerged vibrating blade

Tengs E., Charrassier F., Holst M., Storli P.

International Journal of Applied Mechanics and Engineering

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2019

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Vol. 24, no. 1

131--142

EN

As part of an ongoing study into hydropower runner failure, a submerged, vibrating blade is investigated both experimentally and numerically. The numerical simulations performed are fully coupled acoustic-structural simulations in ANSYS Mechanical. In order to speed up the simulations, a model order reduction technique based on Krylov subspaces is implemented. This paper presents a comparison between the full ANSYS harmonic response and the reduced order model, and shows excellent agreement. The speedup factor obtained by using the reduced order model is shown to be between one and two orders of magnitude. The number of dimensions in the reduced subspace needed for accurate results is investigated, and confirms what is found in other studies on similar model order reduction applications. In addition, experimental results are available for validation, and show good match when not too far from the resonance peak.

9

Analysis of unsteady forces acting on a slender cylinder

Ziółkowski P. J., Witkowski W., Sobczyk B.

Transactions of the Institute of Fluid-Flow Machinery

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2018

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nr 140

23--38

EN

Developments in construction engineering (new materials, construction techniques) facilitate the design of very flexible, light structures with low damping which unfortunately results in higher susceptibility of these structures to wind action. It is therefore necessary to use more accurate scientific tools in the engineering phase of these structures. Analytical methods for considering wind effects on structures encounter difficulties with respect to mathematical formulations of aerodynamic forces. In this paper a 2D numerical model has been described which considers the fluid domain with respect to a cylindrical obstacle. This 2D model has been discretized using the finite volume method, and numerical simulations have been undertaken in order to describe the unsteady flow conditions within the analyzed domain. The simulations have been performed with boundary conditions characterizing the flow past a cylindrical obstacle. The results have been compared with the literature data from similar experiments. On the basis of the flow characteristics obtained, as well as the spatial distributions of the flow parameters, a model for further 3D analyses was selected. Next, a 3D numerical study of unsteady flow forces acting on a slender cylinder has been analyzed. Toward the end, a two-way fluid solid interaction approach has been utilized, which incorporates a computational fluid dynamics approach combined with computational solid dynamics.

10

Analiza wytrzymałościowa tarczy wirnikowej turbogeneratora ORC o mocy 30 kWe z uwzględnieniem sił aerodynamicznych

Bagiński P., Żywica G.

Przegląd Mechaniczny

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2017

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nr 9

16--18

PL

Autorzy artykułu przedstawiają obliczenia wytrzymałościowe tarczy wirnikowej prototypowego turbogeneratora o mocy 30 kWe pracującego w układzie ORC z silnikiem spalinowym. Do obliczeń użyto programu ANSYS Workbench, który pozwolił wyznaczyć naprężenia i odkształcenia wywołane wirowaniem tarczy mikroturbiny przy uwzględnieniu rozkładu sił i temperatur w układzie łopatkowym. Uzyskane wyniki wykazały, że koło wirnikowe wraz z pokrywą powinno pracować w zakresie naprężeń dopuszczalnych, poniżej granicy sprężystości. Odkształcenia i przemieszczenia tarczy wirnikowej były również na akceptowalnym poziomie.

EN

This article presents the strength analysis of the rotor disk of a 30 kW turbogenerator prototype operating in an ORC system equipped with a combustion engine. ANSYS Workbench was used as a solver that allowed for the determination of stresses and deformations of the microturbine disk in motion, taking into consideration force and temperature distributions in the blade system. The obtained results show that the rotor disk with a cover installed is capable of operating within the permissible stresses, below the limit of elasticity. The deformations and displacements of the rotor disk were also at an acceptable level.

11

Identification and modelling of the pulsatile blood flow in section of elastic large blood vessel

Nowak Marcin

Archiwum Instytutu Techniki Cieplnej

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2017

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Vol. 3

5--30

EN

Modelling of the blood flow process using computational fluid dynamics (CFD) and finite element method (FEM) can improve considerably understanding, diagnosis and prevention of cardiovascular diseases in non-invasively way. Moreover, studying of processes inside human body helps to develop products that interacts with organism. For example, automotive and sport industry find it very useful for designing their products, reducing the cost for R&D at the same time. The aim of this study is to create a model of the blood flow in elastic blood vessel. Assumption of rigid blood vessel wall decreases the correctness of results, especially when the vessel undergoes quite large deformations. During cardiac cycle, the fluid flow induces forces from the time-varying blood pressure and wall shear stress. These forces causes strains of elastic vessels, which result in modification of the flow area. This was the motivation of using FluidStructure-Interaction (FSI) method. In this research a real geometry model from 8-year old female patient with a moderate thoracic aortic coarctation (CoA) was analyzed. The geometry was obtained by gadoliniumenhanced Magnetic Resonance Angiography (MRA). Model includes ascending aorta, arch of aorta, descending aorta, brachiocephalic artery with right subclavian and right common carotid artery, left common carotid artery, left subclavian artery. Due to the lack of the detailed data concerning arterial wall geometry, the wall thickness was calculated as 10% of the effective vessel radius. The simulation was performed using 2-way iteratively implicit approach of FSI. This approach couples two numerical solvers: ANSYS Mechanical (Finite Element Method) and ANSYS Fluent (Finite Volume Method). Pulsatile flow profile was implemented via User Defined Function (UDF) to mimic the cardiac cycle. This UDF consist of five polynomials created on twenty measuring points. The blood flow was modelled as laminar, single-phase, using non-Newtonian Carreau viscosity model.

PL

Modelowanie procesu przepływu krwi oparte na numerycznej mechanice płynów oraz metodzie elementów skończonych może znacznie poprawić zrozumienie, diagnozę i profilaktykę chorób układu krążenia w sposób nieinwazyjny. Co więcej, analiza procesów zachodzących wewnątrz ludzkiego ciała pomaga w rozwoju produktów oddziałujących w pewien sposób na organizm. Przykładowo, w przemyśle samochodowym oraz sportowym jest ona niezwykle użyteczna na etapie projektowania produktu, jednocześnie zmniejszając nakład finansowy na badania i rozwój. Celem niniejszego badania było utworzenie modelu przepływu krwi w elastycznym naczyniu krwionośnym. Założenie nieodkształcalności ścian obniża poprawność wyników, szczególnie, gdy naczynie poddawane jest stosunkowo dużym odkształceniom. Podczas cyklu pracy serca, przepływ płynu wywiera siły wynikające ze zmiennego w czasie ciśnienia krwi i naprężeń ścinających. Siły te powodują odkształcenia elastycznych naczyń, co skutkuje modyfikacją powierzchni przepływu. Proces ten był argumentem do użycia metody Fluid-Structure Interaction. W badaniu wykorzystano rzeczywistą geometrię od ośmioletniej pacjentki z koarktacją części piersiowej aorty. Geometrię uzyskano na drodze wzmocnionej angiografii (MRA). Model zawiera aortę wstępującą, zstępującą, łuk aorty oraz górne odgałęzienia. Z powodu braku szczegółowych danych dotyczących geometrii ścian naczyń, ich grubość została założona jako 10% lokalnego promienia. Symulacja została przeprowadzona przy użyciu obustronnego sprzężenia. Podejście to jest związane z dwiema aplikacjami: ANSYS Mechanical (Metoda Elementów Skończonych) oraz ANSYS Fluent (Metoda Objętości Skończonych). Pulsacyjny profil przepływu krwi został zaimplementowany przy użyciu procedur definiowanych przez użytkownika (UDF – User Defined Function). Jest on złożony z pięciu wielomianów, utworzonych na bazie dwudziestu punktów pomiarowych. Przepływ krwi został zamodelowany jako jednofazowy, a płyn jako nienewtonowski (model Carreau).

12

Porównanie sił aerodynamicznych działających na połowę torusa i dwa walce o tej samej długości

Padewska A., Szczepaniak P., Wawrzynek A.

Modelowanie Inżynierskie

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2016

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T. 29, nr 60

52--57

PL

W Eurokodzie PN-EN 1991-1-4 [11] brakuje wytycznych projektowych umożliwiających oszacowanie sił aerodynamicznych działających na obiekty o nietypowym kształcie. W referacie porównano zatem charakter przepływu powietrza o dużych, coraz częściej występujących na świecie prędkościach w pobliżu obiektów w kształcie połowy torusa (np. fragmentu zjeżdżalni wodnej) i dwóch walców o sumarycznej długości równej długości osi połowy torusa, ustawionych poziomo oraz odchylonych od poziomej płaszczyzny pod kątem ß = 45°. Porównano również siły aerodynamiczne działające na połowę torusa - opór aerodynamiczny i poziomą siłę prostopadłą do niego, z siłami działającymi na walce. Wyniki otrzymano na podstawie analiz numerycznych: MES i MOS, wykorzystując moduły: CFD (Computational Fluid Dynamics) i FSI (Fluid-Structure Interaction).

EN

Eurocode EN 1991-1-4 [11] does not include issues concerning wind loads acting on constructions in a non-typical shape. Therefore, in the paper the character of high-speed air flow, which increasingly occurs in the world around objects in the shape of a half - torus (eg. a fragment of a water slide) and two cylinders positioned horizontally and inclined to the horizontal plane at an angle ß = 45° were compared. Also aerodynamic forces acting on a half of the torus - an aerodynamic resistance and a horizontal force perpendicular to the direction of a wind velocity, were compared with forces acting on cylinders. Results are based on numerical analysis: FEM and FVM using the following modules: CFD (Computational Fluid Dynamics) and FSI (Fluid-Structure Interaction).

13

Lattice-Boltzman Method in CFD modelling of direct acting relief valve

Domagała M.

Czasopismo Techniczne. Mechanika

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2016

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Y. 113, iss. 4-M

101--106

EN

This paper presents the modelling of a direct acting relief valve with the use of the new approach of CFD techniques which uses the Lattice Boltzman Method (LBM). It allows for eliminating the biggest problem that occurs during the simulation of a valve operation, which is the motion of a working component. During traditional CFD modeling, a deformed mesh has to be used in such a case, which may lead to the occurrence of computational cells with negative volume and, as a consequence, remeshing of fluid domain.

PL

W artykule przedstawiono zastosowanie metody symulacji numerycznych przepływu wykorzystującą metodę siatkową Boltzmana (LBM) w modelowaniu zaworu przelewowego bezpośredniego działania. Umożliwia ona wyeliminowanie największego problemu, jaki występuje podczas symulacji pracy zaworu przelewowego tradycyjnymi metodami CFD, którą jest konieczność wykorzystywania deformującej się siatki modelu dyskretnego.

14

Modelling of direct acting relief valve using CFD-FSI simulation

Domagała M.

Czasopismo Techniczne. Mechanika

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2015

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Y. 112, iss. 2-M

43--48

EN

This paper presents an attempt of using new capabilities of CFD tools in field of fluid-structure interaction simulation, which is called “immersed solids”. This techniques treats solids as objects immersed into fluid domain which moves along with the fluid. This paper presents comparison of selected CFD results of traditional approach and 'immersed solids' technique on example of direct acting relief valve.

PL

W artykule przedstawiono wykorzystanie nowych możliwości modelowania CFD w zakresie oddziaływania cieczy na ciała stałe przy wykorzystaniu techniki immersed solids. Na przykładzie zaworu przelewowego bezpośredniego działania przedstawiono kilka wybranych wyników symulacji CFD i porównanie z tradycyjnym podejściem w modelowaniu CFD zaworów hydraulicznych.

15

Analysis of fluid-structure interaction of a torus subjected to wind loads

Padewska A., Szczepaniak P., Wawrzynek A.

Computer Assisted Methods in Engineering and Science

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2014

|

Vol. 21, no. 2

151--167

EN

In the paper the aerodynamic forces acting on a part of a water slide or other object with curved, tubular shape, depending on the section of a torus and value of the wind velocity, were obtained. This was done by means of finite element method (FEM) and finite volume method (FVM) computer simulations, using modules: computational fluid dynamics (CFD) and fluid-structure interaction (FSI) and taking into account the Eurocode EN 1991-1-4.

16

Badania samochodu napędzanego silnikiem FSI - systemem elektronicznego sterowania bezpośrednim wtryskiem benzyny

Typańska D., Putz Ł.

Prace Instytutu Elektrotechniki

|

2012

|

Z. 260

107-119

PL

W artykule zaprezentowano szczegółową analizę systemu bezpośredniego wtrysku benzyny FSI (Fuel Stratified Injection) stosowanego w samochodach koncernu Volkswagen Group. W pracy przedstawiono charakterystyczne elementy budowy z opisem ich wpływu na działanie tego typu silnika. Następnie przedstawiono wyniki badań mocy silnika, momentu obrotowego, emisji zanieczyszczeń oraz zużycia paliwa, przeprowadzonych na modelu VW Passat 2.0 FSI oraz porównano z wynikami badań odpowiednika o wtrysku pośrednim - VW Passat 2.0 MPI.

EN

In this article is presented a detailed analysis of FSI (Fuel stratified injection) gasoline direct injection system used in the Volkswagen Group cars. In the paper are also presented characteristic elements of the construction with a description of their impact on the operation such a type of engine. Next are presented results of research like engine power, torque, exhaust emissions and fuel consumption, carried out on the VW Passat 2.0 FSI and compared with test results in the indirect injection equivalent - VW Passat 2.0 MPI.

17

Goal-oriented mesh adaptivity for fluid-structure interaction with application to heart-valve settings

Wick T.

Archive of Mechanical Engineering

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2012

|

Vol. LIX, nr 1

73-99

EN

We apply a fluid-structure interaction method to simulate prototypical dynamics of the aortic heart-valve. Our method of choice is based on a monolithic coupling scheme for fluid-structure interactions in which the fluid equations are rewritten in the 'arbitrary Lagrangian Eulerian' (ALE) framework. To prevent the backflow of structure waves because of their hyperbolic nature, a damped structure equation is solved on an artificial layer that is used to prolongate the computational domain. The increased computational cost in the presence of the artificial layer is resolved by using local mesh adaption. In particular, heuristic mesh refinement techniques are compared to rigorous goal-oriented mesh adaption with the dual weighted residual (DWR) method. A version of this method is developed for stationary settings. For the nonstationary test cases the indicators are obtained by a heuristic error estimator, which has a good performance for the measurement of wall stresses. The results for prototypical problems demonstrate that heart-valve dynamics can be treated with our proposed concepts and that the DWR method performs best with respect to a certain target functional.

PL

W artykule przedstawiono analizę zagadnienia oddziaływania płyn-struktura (FSI) w komputerowej symulacji pracy zastawki serca. Przedstawiono monolityczne sformułowanie tego zagadnienia, w którym równania dla struktury i płynu rozwiązywane są w pełnym sprzężeniu, przy czym do opisu ruchu płynu stosowane jest podejście typu Arbitrary Lagrangian-Euelerian (ALE). Zaproponowano metodę eliminacji zjawiska niefizycznego odbicia fal odkształceń struktury, polegającą na wprowadzeniu sztucznej dyssypacji energii tych fal w części brzegu obszaru położonej za zastawkami. W celu zwiększenia efektywności obliczeniowej wprowadzono lokalną adaptację siatki. W szczególności, porównano heurystyczne techniki adaptacji siatki z techniką opartą na wykorzystaniu ważonego residuum sprzężonego (Dual Weighted Residual, DWR). Przedstawiono wyniki obliczeń testowych demonstrujące poprawność zaproponowanego podejścia oraz skuteczność metody adaptacyjnej DWR.

18

Innovative solutions of system direct injection of petrol fsi (fuel stratified injection)

Olszowski S., Olszowski T.

Logistyka

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2008

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nr 2

EN

In the article innovative solutions of direct injection of petrol system have been introduced. The innovative ideas of the fuel or air feed system are shown as well. Advantages which appear to be the results of such technical solutions are described too.

PL

W artykule zaprezentowano nowe rozwiązania zastosowane w systemie bezpośredniego wtrysku benzyny. Przedstawiono innowacyjne koncepcje układu zasilania powietrzem oraz paliwem. Przybliżono zalety i korzyści wynikające z możliwości zastosowania tego typu rozwiązań technicznych.

19

Development of a method for the analysis of mixed friction problems

Albers A., Nowicki L., Enkler H. G.

International Journal of Applied Mechanics and Engineering

|

2006

|

Vol. 11, no 3

479-490

EN

This article deals with a holistic approach to the numerical analysis of mixed friction. By means of the finite element method, the influence of a set of selected parameters on the behaviour of the frictional contact system will be determined. For this, a three-dimensional parameterized FEM-model will be presented, which couples the equations of the structure mechanics with the Navier-Stokes-theory. To consider the roughness of machined surfaces, virtual surfaces are generated to represent the characteristics of usual manufacturing methods. At the Institute of product development, the theoretical approaches were implemented into a software code, which makes use of stochastic algorithms to obtain rough surfaces with the desired characteristics. The characterization of these virtual surfaces is done by the abbot curve and a roughness parameter. The generation of the surfaces is done by an evolutionary optimizer.