Introduction_to_CFD_Using_ANSYS_Fluent.pptx

Introduction to ANSYS

1. Summary for ANSYS Tutorials 1,2 and3 Presenter: Dr. Abdellatif Sadeq

2. Outline Chapter 1: Fluid Flow and Heat Transfer in a Mixing Elbow Chapter 2: Parametric Analysis in ANSYS Workbench Using ANSYS Fluent Chapter 3: Introduction to Extra Features Available in ANSYS Fluent Chapter 4: Using the Non-Premixed Combustion Model

3. Chapter 1:Fluid Flow and Heat Transfer in a Mixing Elbow Introduction Problem Definition Designing the Geometry Meshing the Geometry Setting Up the CFD Simulation in ANSYS Fluent Displaying Results in ANSYS Fluent and CFD-Post Obtaining the Solution

4. Chapter 1: Introduction This tutorial illustrates using ANSYS Fluent fluid flow systems in ANSYS Workbench to set up and solve a three-dimensional turbulent fluid-flow and heat-transfer problem in a mixing elbow . It is designed to introduce you to the ANSYS Workbench tool set using a simple geometry. Guided by the steps that follow, you will create the elbow geometry and the corresponding computational mesh using the geometry and meshing tools within ANSYS Workbench. You will use ANSYS Fluent to set up and solve the CFD problem, then visualize the results in both ANSYS Fluent and in the CFD-Post post processing tool . Some capabilities of ANSYS Workbench (for example, duplicating fluid flow systems, connecting systems, and comparing multiple data sets) are also examined in this tutorial.

5. Chapter 1: Problem Definition A cold fluid at 293.15 K flows into the pipe through a large inlet and mixes with a warmer fluid at 313.15 K that enters through a smaller inlet located at the elbow. The mixing elbow configuration is encountered in piping systems in power plants and process industries. It is often important to predict the flow field and temperature field in the area of the mixing region in order to properly design the junction.

6. Chapter 1: Designing the Geometry 2 1 4 3

7. Chapter 1: Meshing the Geometry Size Function Curvature Relevance center   Fine Smoothing High Transition Slow Min. Size 8.5514e-0.005m   Max. Size 8.5514e-0.003m   Growth Rate 1.2 Nodes 35026 Elements 118635

8. Chapter 1: Setting Up the CFD Simulation in ANSYS Fluent Setting Up the Units Setting Up the Solver

9. Chapter 1: Setting Up the CFD Simulation in ANSYS Fluent Enabling the k-epsilon Model Defining the Material

10. Chapter 1: Setting Up the CFD Simulation in ANSYS Fluent Specifying the Boundary Conditions

11. Chapter 1: Setting Up the CFD Simulation in ANSYS Fluent Setting Up the Solution Method Initialize the Solution

12. Chapter 1: Setting Up the CFD Simulation in ANSYS Fluent Setting Up the Convergence Criteria Determine the Number of Iterations & Start the Calculations

13. Chapter 1: Displaying Results in ANSYS Fluent and CFD-Post Insert a New Contour for the Velocity and Define its Details Insert a New Contour for the Temperature and Define its Details

14. Velocity profile at the symmetry plane

15. Temperature profile at the symmetry plane

16. Chapter 1: Duplicating the Fluent-Based Fluid Flow Analysis System Create a Copy of the First Fluid Flow (Fluent) Compare The Results at Once

17. Comparison between the Velocity Profile of Two Different Geometries

18. Chapter 2: Parametric Analysis in ANSYS Workbench Using ANSYS Fluent Introduction Problem Definition Designing the Geometry Meshing the Geometry Setting Up the CFD Simulation in ANSYS Fluent Displaying Results in ANSYS Fluent and CFD-Post Using the Parametric Analysis in ANSYS Workbench

19. Chapter 2: Introduction This tutorial illustrates using an ANSYS Fluent fluid flow system in ANSYS Workbench to set up and solve a three-dimensional turbulent fluid flow and heat transfer problem in a divergent pipe flow. ANSYS Workbench uses parameters and design points to allow you to run optimization and what-if scenarios. You can define both input and output parameters in ANSYS Fluent that can be used in your ANSYS Workbench project. You can also define parameters in other applications including ANSYS Design Modeler and ANSYS CFD-Post. Once you have defined parameters for your system, a Parameters cell is added to the system and the Parameter Set bus bar is added to your project. This tutorial is designed to introduce you to the parametric analysis utility available in ANSYS Workbench.

20. Chapter 2: Problem Definition There is heat exchange between hot and cold fluid in a diverging pipe, in which the hot fluid enters in the diverging pipe and cold fluid enters into the pipe at 6 locations at different velocity and different temperature. The velocity for the hot fluid is 0.001 m/s and the temperature is 360K. For the cold fluid, the velocity and the temperature are as the following: V1= 0.001 m/s T1= 300K, V2= 0.001 m/s T2= 300K, V3= 0.003 m/s T3= 290K, V4= 0.003 m/s T4= 290K, V5= 0.004 m/s T5= 280K, V6= 0.004 m/s T6= 280K,

21. Chapter 2: Designing the Geometry

22. Chapter 2: Meshing the Geometry Size Function Curvature Relevance center   Coarse Smoothing Medium Transition Slow Min. Size 5.2958e-0.005m   Max. Size 5.2958e-0.003m   Growth Rate 1.2 Nodes 8556 Elements 40309

23. Chapter 2: Meshing the Geometry

24. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Setting Up the Units Setting Up the Solver

25. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Enabling the k-epsilon Model Defining the Material

26. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Specifying the Boundary Conditions

27. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Specifying All the Input Parameters

28. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Setting Up the Solution Method Initialize the Solution

29. Chapter 2: Setting Up the CFD Simulation in ANSYS Fluent Decrease the Residuals for a Better Accuracy of Results Determine the Number of Iterations & Start the Calculations

30. Chapter 2: Displaying Results in ANSYS Fluent and CFD-Post Insert a New Plane for the Temperature and Define its Details Locate Contour 3 on Plane 2

31. Temperature profile at Plane 2

32. Temperature profile at the Walls

33. Chapter 2: Using the Parametric Analysis in ANSYS Workbench Define the Outlet Temperature as an Output Parameter Define the Outlet Velocity as an Output Parameter

34. Chapter 2: Using the Parametric Analysis in ANSYS Workbench After defining all the input and output parameters, start varying the values of the input parameters to check for the variation in the values of the output parameters

35. Chapter 3: Introduction to Extra Features Available in ANSYS Fluent This chapter demonstrates how to do the following: Perform the mesh-related activities using the Setting Up Domain ribbon tab Create a surface report definition and use it as a convergence criterion. Check for the mass conservation in post-processing Making x-y plot for the preliminary solution Define a custom field function in ANSYS Fluent Change the solver method to coupled in order to increase the convergence speed. Adapt the mesh based on the temperature gradient to further improve the prediction of the temperature field. Run the ANSYS Fluent solver in parallel.

36. Chapter 3: Perform the mesh-related activities using the Setting Up Domain ribbon tab In this step, you will perform the mesh-related activities using the Setting Up Domain ribbon tab ( Mesh group box). ANSYS Fluent will report the results of the mesh check in the console.

37. Chapter 3: Create a Surface Report Definition and Use it as a Convergence Criterion.

38. Chapter 3: Create a Surface Report Definition and Use it as a Convergence Criterion.

39. Chapter 3: Check for the Mass Conservation in Post-Processing

40. Chapter 3: Making x-y plot for the Preliminary Solution

41. Chapter 3: Define a Custom Field Function in ANSYS Fluent

42. Chapter 3: Change the Solver Method to Coupled in Order to Increase the Convergence Speed. The solution will converge in approximately 36 iterations which is faster than the SIMPLE pressure-velocity coupling

43. Chapter 3: Adapt the Mesh Based on the Temperature Gradient to Further Improve the Prediction of the Temperature Field. Cells marked for adaption

44. Chapter 3: Run the ANSYS Fluent solver in parallel. When you use the parallel solver, you need to subdivide (or partition) the mesh into groups of cells that can be solved on separate processors.

45. Contours of the dynamic head using the parallel solver

46. Chapter 4: Using the Non-Premixed Combustion Model Introduction Problem Definition Checking and Scaling the Mesh Specifying Solver and Analysis Type Defining Materials and Properties Specifying Boundary Conditions Obtaining the Solution Postprocessing Energy Balances Reporting

47. Chapter 4: Introduction The goal of this tutorial is to accurately model the combustion processes in a 300 KW BERL combustor. The reaction can be modeled using either the species transport model or the non-premixed combustion model. In this tutorial you will set up and solve a natural gas combustion problem using the non-premixed combustion model for the reaction chemistry. turbulence-chemistry interaction is modeled using a β -function for the Probability Density Function (PDF). This tutorial demonstrates how to do the following: • Define inputs for modeling non-premixed combustion chemistry. • Prepare the PDF table in ANSYS Fluent. • Solve a natural gas combustion simulation problem. • Use the Discrete Ordinates (DO) radiation model for combustion applications. • Use the k- ε turbulence model.

48. Chapter 4: Problem Definition The flow considered is an unstaged natural gas flame in a 300-kW swirl-stabilized burner. The furnace is vertically-fired and of octagonal cross-section with a conical furnace hood and a cylindrical exhaust duct. The furnace walls are capable of being refractory-lined or water-cooled. The burner features 24 radial fuel ports and a bluff center body. Air is introduced through an annular inlet and movable swirl blocks are used to impart swirl assuming 2D axisymmetric. The boundary condition profiles, velocity inlet boundary conditions of the gas, and temperature boundary conditions are based on experimental data

49. Chapter 4: Checking and Scaling the Mesh

50. Chapter 4: Specifying Solver and Analysis Type Pressure based solver type with axisymmetric swirl Standard k-epsilon model

51. Chapter 4: Specifying Solver and Analysis Type Enable the Discrete Ordinates (DO) radiation model Enable the Non-Premixed Combustion model.

52. Chapter 4: Specifying Solver and Analysis Type Add and define the boundary species

53. Chapter 4: Specifying Solver and Analysis Type Obtain the PDF table

54. Chapter 4: Specifying Solver and Analysis Type Display the non-adiabatic temperature look-up table on the adiabatic enthalpy slice

55. Chapter 4: Defining Materials and Properties Select PDF mixture form the drop-down list

56. Chapter 4: Specifying Boundary Conditions Set the boundary conditions for the pressure outlet Set the boundary conditions for the velocity inlet

57. Chapter 4: Specifying Boundary Conditions Set the boundary conditions for at the fuel inlet

58. Chapter 4: Specifying Boundary Conditions Set the boundary conditions for at the walls

59. Chapter 4: Specifying Boundary Conditions Plot the temperature profile for wall 9

60. Chapter 4: Specifying Boundary Conditions Profile plot of axial-velocity for the swirling air inlet

61. Chapter 4: Obtaining the Solution Select coupled for pressure-velocity coupling and PRESTO for the pressure

62. Chapter 4: Obtaining the Solution Setting up the solution control (convergence criteria)

63. Chapter 4: Obtaining the Solution Setting up the residuals (convergence criteria)

64. Chapter 4: Obtaining the Solution Initialize the solution (hybrid initialization) Set up the number of iterations

65. Chapter 4: Postprocessing Display the predicted temperature field

66. Temperature contours

67. Velocity contours

68. Contours of Mass Fraction of O2

69. Chapter 4: Energy Balances Reporting Display the predicted temperature field

70. Chapter 4: Energy Balances Reporting Compute the mass weighted average of the temperature at the pressure outlet

71. Thanks for your Attention