Wyniki wyszukiwania - BazTech

1

Application of Geometric Simulation for Determination of Dynamic Undeformed Chip Thickness in Milling

Bombiński Sebastian, Jemielniak Krzysztof

Advances in Science and Technology. Research Journal

|

2023

|

Vol. 17, no 1

173--181

EN

Self-excited vibration is a significant constraint on productivity and production quality, which makes various forms of virtual machining widely used to find stable conditions before starting the actual machining operation. Numerical simulation of self-excited vibration, although much slower than analytical solutions, makes it possible to consider the nonlinearity of the process and its continuous variation. In 5-axis milling, predicting the instantaneous cross-sections of the uncut chip is very difficult, so geometric simulation is readily used to check the correctness of the NC program and the obtained shape of the workpiece. However, the known solutions take into consideration only programmed movements of the tool relative to the workpiece without considering vibrations, and those in which attempts have been made to consider vibrations have significant limitations. This paper uses a Geometric Simulator that determines the nominal positions of the tool relative to the workpiece, to which the displacements due to vibration, determined by the Dynamic Simulator, are added, making it possible to effectively determine the dynamic thickness of the cut layer and the trace on the workpiece material left by the vibrating tool. The use of geometric simulation, in which the material is represented by discrete voxels, introduces signal quantization, that is, the limited resolution of undeformed chip thickness and trace left on the machined surface. The paper presents the effect of voxel dimension on the accuracy of the simulation of self-excited vibrations.

2

Investigation of mechanical motion amplification for vibration energy harvesting

Satpute Nitin, Iwaniec Marek, Narina Ramesh, Satpute Sarika

Vibrations in Physical Systems

|

2022

|

Vol. 33, nr 1

art. no. 2022113

EN

Vibration Energy Harvesting is being investigated for autonomous sensors and actuators that mainly utilize ambient and machine induced vibrations. Recently mechanical motion amplification is incorporated for improving power to weight ratio of vibration harvesters. The present study is motivated to investigate mechanical motion amplification characteristics with different configurations. The parameters investigated are motion amplification ratio, force transmissibility characteristics, weight of the electrical generator, effective damping coefficient achieved and linear nature of damping. Numerical analysis has been performed to compare important characteristics of device operating without amplification to that of with amplification with different configuration. The study has been concluded with comments on application of suitable type of amplification mechanism depending on weight/space constraints and desired effective damping coefficient.

3

Improving the operation characteristics of non-insulated overhead power lines

Kozlovskyi Oleksandr, Trushakov Dmitro, Savchenko Oleksandr, Rendzinyak Serhiy, Korud Vasyl

Przegląd Elektrotechniczny

|

2022

|

R. 98, nr 2

28--32

EN

Methods of protection of wires of overhead power lines of group "anti-icing" are analyzed. The expediency of applying the winding method of protection of wires of overhead lines in operation for a long time is shown. Based on numerical simulations of the hydrodynamic problem, the degree of influence of the protective coating on the wind load of the wire is analyzed. The research results showed a decrease in the modified wire's drag coefficient with increasing wind speed.

PL

Przeanalizowano metody ochrony przewodów linii napowietrznych z grupy „przeciwoblodzeniowa”. Pokazano celowość zastosowania metody uzwojenia do ochrony przewodów linii napowietrznych eksploatowanych od dłuższego czasu. Wykorzystując symulacje numeryczne zagadnienia hydrodynamicznego analizowany jest stopień wpływu powłoki ochronnej na obciążenie żyły kabla wiatrem. Wyniki badań wykazały spadek współczynnika rezystancji zmodyfikowanej żyły wraz ze wzrostem prędkości wiatru.

4

Air Pollution Regulations in China: A Policy Simulation Approach with Evolutionary Game

Chu Zhaopeng, Bian Chen, Yang Jun

Problemy Ekorozwoju

|

2022

|

Vol. 17, nr 1

222--233

EN

In the institutional context of China’s political centralization and fiscal decentralization, this study explores the environmental regulations that make the central and local governments join efforts in air pollution control. Policy simulations in an evolutionary game show that the best approach is to internalize environmental costs and benefits in local governments’ objective function. The effectiveness of several policy instruments is examined individually and jointly, including administrative inspection, transfer payment, and environmental taxes. It is shown that in case environmental consequences are not internalized, appropriate application of policy instruments can incentivize goal-oriented local governments to choose the socially optimal strategy.

PL

W kontekście instytucjonalnym chińskiej centralizacji politycznej i decentralizacji fiskalnej, niniejsze badanie analizuje regulacje środowiskowe, które zmuszają rządy centralne i lokalne do wspólnych wysiłków na rzecz kontroli zanieczyszczenia powietrza. Symulacje polityki w grze ewolucyjnej pokazują, że najlepszym podejściem jest internalizacja kosztów i korzyści środowiskowych w funkcji celu samorządu. Skuteczność kilku instrumentów polityki jest badana indywidualnie i wspólnie, w tym kontroli administracyjnej, płatności transferowych i podatków ekologicznych. Wykazano, że w przypadku braku internalizacji konsekwencji środowiskowych, odpowiednie zastosowanie instrumentów polityki może zmotywować zorientowane na cel samorządy lokalne do wyboru społecznie optymalnej strategii.

5

Wpływ dynamiki samolotu i jego stanu lotu na bezpieczeństwo wykonania manewru ominięcia ruchomych przeszkód

Graffstein Jerzy

Pomiary Automatyka Robotyka

|

2022

|

R. 26, nr 1

33--39

PL

Właściwe określenie istotnych czynników wpływających na przebieg wyliczanego manewru uniknięcia kolizji z ruchomymi przeszkodami jest niezbędne w celu zapewnienia bezpiecznego ominięcia ruchomej przeszkody. Jednocześnie w trakcie manewru omijania wymagane jest zachowanie żądanej separacji między samolotem a przeszkodami. Przedmiotem pracy jest analiza sposobu w jaki czynniki wpływają na przebieg manewru antykolizyjnego z uwzględnieniem deformacji trajektorii i zmian przebiegu odległości samolotu od wykrytych przeszkód. Skupiono się na wewnętrznych oddziaływaniach, które wynikają z istotnych zmian zachowania się samolotu. Rozważania zostały zilustrowane wybranymi wynikami z symulacji komputerowych typowych manewrów ominięcia przeszkód, poddanych negatywnym wpływom wybranych czynników. Zaproponowano wytyczne, które powinny umożliwić przeciwdziałanie niekorzystnym oddziaływaniom na realizację wyliczonego manewru.

EN

The exact identification of essential factors affecting the course of evasive manoeuvre, that has been computed to avoid a collision with moving obstacles, is necessary to ensure a safe passing by a moving obstacle. At the same time, during the evasive manoeuvre the pre-defined separation between the airplane and obstacles is required. The matter of presented work is defined as the analysis of influence of factors on execution of anti collision manoeuvre taking into account deformation of flight trajectory and changes of time histories of distance from the airplane to detected obstacles. Attention has been focused on internal interactions, resulting from the essential changes of the airplane’s behaviour. Discussion has been illustrated by selected results of computer simulations, executed for typical manoeuvres performed to avoid obstacles, while affected by adverse impacts of selected factors. The appropriate guidelines have been proposed, that should counteract these adverse effects on realisation of computed manoeuvre.

6

Period verification device for ventilation rate standard rods based on a digital thermal flowmeter

Hu Jiacheng, Sha Ying, Cai Jinhui, Liu Ying, Liu Suijun

Metrology and Measurement Systems

|

2022

|

Vol. 29, nr 1

231--244

EN

Ventilation rate is a physical index that is strictly controlled during cigarette manufacturing because an abnormal ventilation rate can affect the release of mainstream smoke, tar, and other components harmful to human health. Therefore, the standard rod is used for measuring the ventilation rate, which necessitates accurate and effective periodic inspections. In this study, we designed and built a set of special tobacco ventilation rate standard rods to assess the standard device during its verification period and used a digital thermal flowmeter as the flow standard.We determined the micro-pressure adjustment interval through fluid simulation, and conducted an experimental verification based on the simulation results. At the adjustment point where the differential pressure value was 0 Pa, the period verification device was tested under the standard values of 27.38%, 58.83%, and 71.95%. The results show that the measurement errors of the device are -0.42%, 0.55%, and -0.13% respectively, which all meet the verification regulation requirements and indicate that the device is applicable in practical situations.

7

Badania eksperymentalne i symulacje komputerowe ściany osłonowej MB-SR50N HI obciążonej wiatrem

Juraszek Janusz, Woźniczka Piotr, Rusin Dawid

Materiały Budowlane

|

2022

|

nr 9

53--55

PL

W artykule przedstawiono wyniki badań i symulacji numerycznych MES ściany osłonowej MB-SR50N HI wykonanej z profili aluminiowych. Przeprowadzono badania polegające na obciążeniu wiatrem ściany osłonowej, zarówno ciśnieniem, jak i podciśnieniem o wartości 2400 Pa w specjalnej komorze badawczej. Wyznaczono wartości ugięć w wybranych punktach pomiarowych. Zbudowano model numeryczny ściany osłonowej za pomocą systemu MES Abaqus. Uwzględniono nieliniowość geometryczną oraz rzeczywiste obciążenie o wartościach analogicznych, jak w przypadku badań eksperymentalnych. Otrzymane wyniki symulacji numerycznych są porównywalne z rezultatami badań doświadczalnych. Badanie przemieszczeń i ugięć aluminiowo-szklanych ścian osłonowych ma istotne znaczenie z punktu widzenia ich bezpieczeństwa eksploatacyjnego.

EN

This paper presents results of testing and numerical FEM simulations of the MB-SR50N HI curtain wall of aluminium profiles. Wind-load tests were carried out in a special testing chamber making it possible to load the curtain wall with pressure and partial vacuum of 2400 Pa. Values of deflection were determined in selected measuring points. A numerical model of the curtain wall was built using the Abaqus FEM system. Geometrical nonlinearity and the real load with values analogous to those obtained from experiments have been taken into account. The obtained results of numerical simulations are comparable with results of experimental research. The testing of displacements and deflections of aluminium-glass curtain wallsis important from the point of view of their operational safety.

8

Impact of reservoir heterogeneity on the control of water encroachment into gas-condensate reservoirs during CO2 injection

Matkivskyi Serhii, Burachok Oleksandr

Management Systems in Production Engineering

|

2022

|

nr 1 (30)

62--68

EN

The paper evaluates application of CO2 injection for the control of water encroachment from the aquifer into gas-condensate reservoir under active natural water drive. The results of numerical simulations indicated that injection of CO2 at the initial gas-water contact (GWC) level reduces the influx of water into gas-bearing zone and stabilizes the operation of production wells for a longer period. The optimum number of injection wells that leads to the maximum estimated ultimate recovery (EUR) factor was derived based on statistical analysis of the results. The maximum number of injection wells at the moment of CO2 break-through into production wells for homogeneous reservoir is equal to 6.41 (6) and for heterogeneous – 7.74 (8) wells. Study results indicated that with the increase of reservoir heterogeneity, denser injection well pattern is needed for the efficient blockage of aquifer water influx in comparison to homogeneous one with the same conditions. Gas EUR factor for the maximum number of injection wells in homogenous model is equal 64.05% and in heterogeneous – 55.56%. Base depletion case the EURs are 51.72% and 49.44%, respectively. The study results showed the technological efficiency of CO2 injection into the producing reservoir at initial GWC for the reduction of water influx and improvement of ultimate hydrocarbon recovery.

9

Improving irrigation system management: A case study: Bahr Sanhoor Canal, Fayoum, Egypt

Ibrahim Amir Sabry

Journal of Water and Land Development

|

2022

|

no. 53

1--9

EN

Realising the need for improving irrigation system management, the Bahr Sanhoor Canal (BSC) was selected as a case study, and the effect of covering a reach with a concrete box culvert where the irrigation canal passes through a crowded rural area on the efficiency of the canal system was examined. The field inspection of the canal system revealed multiple problems. Two alternatives for improving irrigation management were introduced. A local alternative was offered by applying a suitable numerical model to enhance the efficiency of the current status of the canal system, the water level upstream of the covered part reached 13.54 m, this solution will lower the water levels by approximately 2 m, which is below the bank levels at an affordable cost. Additionally, it will help to avoid the risk of inundating the adjacent residential area. A sustainable and environmental alternative was considered to offer a new path in which the covered reach passed outside the residential area. This alternative is permanent and sustainable. Although the proposed second path to the right of the residential area is the long-term recommendation and is sustainable, any path of flow to either the left or right of the BSC will be associated with initial high costs. The two proposed alternatives may help decision makers improve the performance of irrigation systems.

10

Collapse modes of concrete reinforced square bridge piers under vehicle collision

Zhou Xiuneng, Xie Zhongyou, Zhao Zhixian, Li Cheng

Journal of Theoretical and Applied Mechanics

|

2022

|

Vol. 60 nr 3

375--384

EN

In the field of engineering protection, there is a structural disaster named heavy vehicles impacting column structures. When a heavy truck collides with a reinforced concrete (RC) column at a high velocity, a large impact force generated makes perhaps the column fail and even collapse. Therefore, it is necessary to study the dynamic characteristics during such a disaster, which can provide some reference for structural design, optimization and protection. The RC column impacted by a vehicle could be simplified as a beam fixed at the bottom loaded by a concentrated force, whose deformation is controlled by shearing and bending. In the present work, the ultimate static forces corresponding to shearing and bending collapse are proposed based on theoretical analyses. The model validation is performed using the finite element approach and the theoretical analytical results are in good agreement with the finite element simulation results, which validates the present analytical model. Three cases are simulated by utilizing finite element code ABAQUS, which reveals that the approximate plateau collapse force keeps a long stage beyond the peak failure one. In addition, three collapse modes are observed based on the static force and deformation analysis, validating the present framework which can be used for routine pier design. The work can be extended to estimate collapse modes of building columns under a vehicle collision.

11

Wyniki symulacji numerycznej cyklu roboczego silnika o ZS w programie DIESEL-RK oraz ocena ich użyteczności w procesie planowania badań diagnostycznych okrętowego silnika tłokowego

Puzdrowska Patrycja

Journal of Polish CIMEEAC

|

2022

|

Vol. 17, no 1

74--82

PL

W artykule przedstawiono wyniki symulacji numerycznej procesu roboczego realizowanego w silniku tłokowym o zapłonie samoczynnym. W zastosowanym programie użytkowym DIESEL-RK zaimplementowano silnik laboratoryjny Farymann Diesel typ D10. Wprowadzono wybraną niesprawność jego układu funkcjonalnego zasilania paliwem - obniżone ciśnienie otwarcia wtryskiwacza pwtr. Wyznaczono wartości adekwatnych parametrów diagnostycznych: temperaturę i ciśnienie gazu roboczego w cylindrze Tcyl i pcyl, temperaturę i ciśnienie spalin wylotowych Tsp i psp, temperaturę spalania (płomienia) Tspal, prędkość spalin wylotowych vsp oraz stężenie cząsteczek NOx. Oceniono użyteczność wyników przeprowadzonej symulacji do wyboru analizowanych parametrów struktury konstrukcyjnej silnika oraz do selekcji parametrów, które mogą być wykorzystane w badaniach diagnostycznych silnika laboratoryjnego.

12

Numerical simulations of a flat phantom in the near-field of symmetric dipole antenna

Styła Monika, Styła Sebastian

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

|

2022

|

T. 12, nr 2

73--76

EN

The paper presents a numerical electromagnetic simulations of SAR limited to human tissues based on FDTD algorithm using Sim4Life platform. Flat-bottomed dielectric vessel (flat phantom) and half-wave symmetric dipole antenna were modeled. Simulations were done for the frequencies 0.9 GHz and 0.6 GHz. The analysis were performed according to the IEEE/IEC62704-1 standard and include distributions of electric and magnetic fields around the phantom and antenna. Finally, SAR distributions in the phantom and near the antenna.

PL

W pracy przedstawiono numeryczne symulacje elektromagnetyczne SAR dla tkanek ludzkich w oparciu o algorytm FDTD z wykorzystaniem platformy Sim4Life. Zamodelowano płaskodenny dielektryk (fantom płaski) oraz półfalową symetryczną antenę dipolową. Symulacje wykonano dla częstotliwości 0.9 GHz i 0.6 GHz. Analizy zostały wykonane zgodnie ze standardem IEEE/IEC62704-1 i obejmują rozkłady pól elektrycznych i magnetycznych wokół fantomu i anteny. Na koniec zaprezentowano rozkłady SAR w fantomie i pobliżu anteny.

13

Physical and numerical model of electrocoagulation process with aluminum electrodes for phosphate removal

Halkijevic Ivan, Loncar Goran, Posavcic Hana, Vouk Drazen

Environment Protection Engineering

|

2022

|

Vol. 48, nr 3

53--68

EN

The efficiency of the electrocoagulation process for the removal of phosphate ions (PO43--P) has been analyzed using a batch full-scale reactor with aluminum electrodes. The effects of the flow rate through the reactor applied current density, and reactor volume were the focus of the study. The initial (PO43--P) concentration was reduced by 90% after 90 min of reactor operation time. Additionally, a three-dimensional numerical model for PO43--P removal via the electrocoagulation process is developed that includes the processes of phosphate adsorption and desorption on coagulated/flocculated particles, along with particles settling. Numerical model parametrization relies on the results from the experiments.

14

Comparative assessment of commonly used concrete damage plasticity material parameters

Al-Rifaie Hasan, Mohammed Darbaz

Engineering Transactions

|

2022

|

Vol. 70, iss. 2

157-181

EN

The non-homogeneous and non-linear mechanical behaviour of concrete complicates the numerical simulations of its corresponding material model. The concrete damaged plasticity (CDP) model is one of the most popular constitutive models for concrete. State-of-the-art CDP material parameters are introduced in Abaqus documentation [1], Jankowiak and Łodygowski [2], and Hafezolghorani et al. [3]. Accordingly, this paper presents a novel comparative study of these commonly-used concrete CDP parameters by assessing the response of plain concrete specimens under quasi-static loading conditions. The research conducts standard laboratory tests: compressive strength test of a concrete cube and three-point flexural test of a plain concrete beam. Sophisticated non-linear computational models are built using Abaqus/CAE and analysed using Abaqus/Explicit solver. The results discuss and compare deformations, damage patterns, reaction forces, compressive strength, tensile stress and modulus of rapture. The thorough study concludes that choosing CDP parameters is case-dependant and should be selected carefully.

15

Multi-domain approach to modeling pantograph-catenary interaction

Zdziebko Paweł, Martowicz Adam, Uhl Tadeusz

Eksploatacja i Niezawodność

|

2022

|

Vol. 24, no. 1

130--139

EN

When a railway pantograph interacts with a catenary during the movement of a rail vehicle, several physical phenomena, both mechanical and electrical, occur in the system. These phenomena affect the quality of power supply of a train from traction devices. The unfavourable arcing occurring when there are disturbances of contact between the pantograph’s slider and the catenary contact wire. In turn, it results in energy loss and increased wear of the components of the system. When designing new solutions, computational models are helpful to predict the quality of interaction between the components of the pantograph-contact line system already at the virtual prototyping stage. In this paper, the authors comprehensively present a multi-domain (multiphysics) model, which takes into account necessary conditions for interaction between pantograph elements and a catenary. Finally, the impact of the individual physical domains are analysed and the ones which have a significant impact on the simulation of the operation results are identified.

16

Numeryczna weryfikacja skuteczności wzmocnienia żelbetowego zbiornika na węgiel brunatny

Lytvyn Oleksandr, Miodoński Beniamin, Marcinowski Jakub, Sakharov Volodymyr, Szerszeń-Zamorska Agata

Builder

|

2022

|

R.26, nr 4

16--19

PL

Przedmiotem analiz numerycznych zamieszczonych w pracy jest żelbetowy zbiornik na węgiel brunatny. Pojemność całkowita zbiornika wynosi około 26 tys. ton. W początkowym okresie eksploatacji zasobnika w latach 60. pojawiły się liczne spękania oraz nadmierne deformacje wymuszające podjęcie pilnych działań naprawczych. Wprowadzono wtedy stalowe ściągi podłużne, poprzeczne i ukośne. Skuteczność tych wzmocnień nie była weryfikowana w przeszłości. Inwentaryzacja oraz wykonane w ostatnim czasie badania materiałowe dostarczyły danych użytych w analizach numerycznych, których celem była ocena aktualnego stanu technicznego analizowanego obiektu. Model numeryczny samej konstrukcji został uzupełniony o grunt, na którym zasobnik został posadowiony. Analizy numeryczne zostały wykonane autorskim programem weryfikowanym wcześniej za pomocą innych programów komercyjnych.

EN

The subject of numerical analyzes included in the paper is a reinforced concrete lignite bunker. The total capacity is about 26 thousand tone. In the initial period of the bunker's operation, disturbing symptoms (cracks, excessive deformations) appeared, necessitating taking urgent corrective actions. Then, longitudinal, transverse and diagonal steel ties were introduced. The effectiveness of these reinforcements has not been verified in the past. Their careful inventory and material tests performed recently provided the necessary data to perform numerical analyzes, the purpose of which was to assess the current technical condition of the analyzed object. The numerical model of the structure itself was supplemented with the ground on which the bunker was placed. Numerical analyzes were performed with author’s program that was previously verified with other commercial programs.

17

Numerical Simulation and Analysis of Airflow in the Condensing Zone of Compact Spinning with Lattice Apron

Saty Malik Y. H., Akankwasa Nicholus T., Wang Jun

Autex Research Journal

|

2022

|

Vol. 22, no. 3

258--263

EN

The airflow field pattern in the condensing zone plays a vital role in the pneumatic compact spinning, which significantly affects the yarn's qualities. This study aimed to analyze the effects of the different negative air pressures on fiber condensing in compact spinning with lattice apron using ANSYS. The results of airflow simulations reveal that by increasing the negative pressure, the flow velocity increases, leading to a more tremendous increase in the transverse condensing effects. Additionally, a better convergence led to reduced fiber width and eliminated the spinning triangle. Experimental results showed that the three yarns spun with the highest negative pressure had better strength, hairiness, and evenness than those spun with lower negative pressure.

18

Numerical Investigation of Heat Transfer in Garment Air Gap

Zhang Yijie, Jia Juhong

Autex Research Journal

|

2022

|

Vol. 22, no. 1

89--95

EN

This article aimed to study the characteristics and mechanisms of 3D heat transfer through clothing involving the air gap. A three-dimensional finite volume method is used to obtain the coupled conductive, convective, and radiative heat transfer in a body-air-cloth microclimate system. The flow contours and characteristics of temperature, heat flux, and velocity have been obtained. The reason for the high flux and temperature regions was analyzed. Computational results show that the coupled effect of the air gap and the airflow between the skin and garment strongly influences the temperature and heat flux distribution. There are several high-temperature regions on the clothing and high heat flux regions on the body skin because the conductive heat flux can cross through the narrow air gap and reach the cloth surface easily. The high-speed cooling airflow brings about high forced convective heat flux, which will result in the temperature increase on the upper cloth surface. The radiative heat flux has a strong correlation with the temperature gradient between the body and clothing. But its proportion in the total heat flux is relatively small.

19

Study on the three-phase flow of the water transfer export elbow of natural gas hydrate

Chen Wei, Xu Hai-Liang, Wu Bo, Yang Fang-Qiong

Archives of Mining Sciences

|

2022

|

Vol. 67, no. 2

239--258

EN

The Euler multiphase flow and population equilibrium model were used to simulate the three-phase flow field in the bubble expansion stage of the outlet curved pipe section. The influence of the ratio of the bending diameter and the volume fraction of the gas phase on the pressure loss is revealed, and the safety range of the optimum bending diameter ratio and the volume fraction of the outlet gas phase is determined. The results show that the three-phase flow in the tube is more uniformly distributed in the vertical stage, and when the pipe is curved, the liquid-phase close to the pipe wall gathers along the pipe flank to the outside of the pipe, the solid phase is transferred along the pipe flank to the inside of the pipe, and the gas phase shrinks along the pipe flank to the inner centre. The maximum speed of each phase of the three-phase flow in the elbow is at the wall of the tube from 45° to 60° inside the elbow, and the distribution law along the axial direction of the pipe is about the same as the distribution law of volume fraction. The pressure loss of the elbow decreases with the increase of the bend diameter ratio, when the bend diameter ratio increases to 6, the pressure loss of the pipe decreases sharply, and the pressure loss decreases slowly with the increase of the bend diameter ratio. When the gas phase volume score in the elbow reaches 70%, there will be an obvious wall separation phenomenon, to keep the system in a stable working state and prevent blowout, the gas phase volume score should be controlled within 60%.

20

Simulation of Dendrite Morphology and Micro-Segregation in U-Nb Alloy During Solidification

Su Bin, Liu Jing-Yuan, Zhang Xiao-Peng, Yan Xue-Wei

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 4

1333--1339

EN

Due to the importance of uranium and uranium alloys to national defence and nuclear industrial applications, it is necessary to understand dendrite formation in their solidification structures and to control their microstructures. In this study, a modified cellular automaton model was developed to predict 2-D and 3-D equiaxed dendrite growth in U-Nb alloys. The model takes into account solute diffusion, preferential growth orientation, interface curvature, etc., and the solid fraction increment is calculated using the local level rule method. Using this model, 2-D large-scale and 3-D equiaxed dendrite growth with various crystallographic orientations in the U-5.5Nb alloy were simulated, and the Nb micro-segregation behaviour during solidification was analysed. The simulated results showed reasonable agreement with the as-cast microstructure observed experimentally.