Dissertation > Excellent graduate degree dissertation topics show

Phase Field Method and Numerical Simulations of Dendritic Crystal Growth

Author: SunTingQiang
Tutor: FengLu
School: Tianjin University
Course: Solid Mechanics
Keywords: phase field method explicit scheme directional growth noise equiaxial crystal
CLC: TG113
Type: Master's thesis
Year: 2010
Downloads: 87
Quote: 0
Read: Download Dissertation

Abstract


In the process of metal solidification, the numerical simulations of the dendritic crystal growth is an important part of materials science field. Its result is practical guiding significance to effectively control the growth of metal materials. At the following section, I will briefly introduce the main contents of the paper.(1) We propose the governing equations of phase field and temperature field bas- ed on phase transition theory of Ginzburg-Landau; we use phase field order parameterφto distinguish the solid, the liquid and solid-liquid interface; we use explicit scheme which applys forward Euler in time and centered-differencing in space to the governing equations.(2) Using 2-dimensional scheme simulate the phase field and temperature field, and get 2-dimensional picture of phase field and temperature field;furthermore, we simulate the variations of the dendritic crystal’s structures when we change the governing parameter; we simulate the tip radius and the tip velocity of the dendritic crystal by analysis and calculation to qualitatively analyse the variations of the dendritic morphology, get the curves changes with the time, find that the tip radius decreases continuously with the time and remain unchanged at last, and the dendrite tip velocity decreases rapidly and tend to stable at last.(3) We simulate the directional and competitive growth of many isotropic dendrit- es by introducting the so-called“noise”, and get that dendrite will select the superior and eliminating the inferior; furthermore, we simulate the dendrite morphology of multiple dendritic directional and competitive growth, and find that the model domain will be filled with the solid of the undercooled melt; we also simulate the solid fraction changed with the time by analysis and calculation to qualitatively analyse the variations of dendritic crystal when we change the governing parameter.(4) In order to simulate the growth of 3-dimensional equiaxial crystal, we improve the 2-dimensional governing equations to be suitable for the 3-dimensional modeling and numerical simulations based on the 2-dimensional modeling and numerical simulations, and using the explicit scheme to apply difference to 2-dimensional phase field and temperature field governing equations; simulate the morphology structure of the isotropic single equiaxial crystal, and simulate the growth of the isotropic multiple equiaxal crystal, and compare the variations of the morphology structure between 2D and 3D dendritic crystal growth, and find that they are almost same with each other.

Related Dissertations

  1. Design of Servo Control System with Linear Motor Based on Digital Filter Technology,TM359.4
  2. Packet Loss Recovering Technology for Speech Transmission over Network,TN912.3
  3. Research and Implementation on Content-Based Clothing Image Retrieval,TP391.41
  4. Research on Servo Control System of Gyro-Stabilized Platform,TJ765
  5. Research of Acoustic Signal Acquisition System Based on DSP,TP274.2
  6. Study of Acoustical Signal Transmitter Which Based on Sigma-Delta Modulation,TN761
  7. Experience · Memory · narrative,I712.074
  8. Moving target trajectory analysis based Intelligent Traffic Monitoring System,TP277
  9. Experimental Improvement of Continuous Variable Entanglement Enhancement,O431.2
  10. Uniform Image Quality Achieved by Individual Tube Current Modulation in Coronary CT Angiography: Preliminary Study,R816.2
  11. Research of Adaptive Active Noise Control Based on Neural Network,TP183
  12. The surface geometry noise removal of non- local variational model,TP391.41
  13. Research of Image Enhancing of Vein Based on Fuzzy Theory,TP391.41
  14. Anlysis and Control the Noise of Low Pressure Gear Pump,TH325
  15. Analysis and Design of Low-Noise Charge-Pump PLL,TN911.8
  16. Charge-Pump PLL Z-domain Analysis and Low Noise Design,TN911.8
  17. Research on Precoding for MIMO System,TN919.72
  18. The Design and Realization of Image Processing in Vehicle-mounted Pavement Crack Detection System,TP391.41
  19. Research on Noise Reducation and Color Interpolation Algorithms Based on Bayer Pattern Images for Digital Camera,TP391.41
  20. Research on Image Denoising Algorithm in Machine Vision System,TP391.41
  21. The Research on Noise Impact Evaluation Method for High-speed Railway,U238

CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metallurgy ( Physical Metallurgy ) > Metallographic microstructure and properties of the (metal )
© 2012 www.DissertationTopic.Net  Mobile