Turbulence

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Course Unit Code338-0527/02
Number of ECTS Credits Allocated3 ECTS credits
Type of Course Unit *Optional
Level of Course Unit *Second Cycle
Year of Study *Second Year
Semester when the Course Unit is deliveredSummer Semester
Mode of DeliveryFace-to-face
Language of InstructionCzech
Prerequisites and Co-Requisites Course succeeds to compulsory courses of previous semester
Name of Lecturer(s)Personal IDName
KOZ30prof. RNDr. Milada Kozubková, CSc.
BOJ01doc. Ing. Marian Bojko, Ph.D.
BLE02doc. Ing. Tomáš Blejchař, Ph.D.
Summary
Students will become introduce with the possibilities of simulation of turbulent / laminar fluid flow in different areas of mechanical engineering, civil engineering, aviation, metallurgy and other fields, where there are devices and machines that contain fluid, or use it for their activities. They will create 3/2D CFD models of real equipment in ANSYS-CFX.
Learning Outcomes of the Course Unit
Students will become familiar with the possibilities of simulation of turbulent / laminar flow of fluids in various fields of engineering, civil engineering, aviation, metallurgy and other areas where there are equipment and machinery, which contain liquid, or use it for their activities. They create 2D and 3D CFD models of real devices in an ANSYS-CFX. When creating a geometric model, students will build on previous knowledge of drawing in higher CAD systems. Students will analyse the assignment of tasks solved in the basic knowledge acquired in the course Fluid Mechanics. They will draw the CFD simulation of airflow around the body, heat transfer, the interaction of two different fluids. Students will interpret the results of simulations and analyse the flow. Based on the simulation results the important parameters for analysis equipment or machinery unit will be predicted. Students will become familiar with the possibilities of CFD simulations and their areas of application and will be able to solve basic problems of fluid mechanics.
Course Contents
L - Lecture, E-Exercise

1. L.: Introduction, numerical modeling of fluid flow - various commercial systems, ANSYS CFX, CFX Integration types of tasks in the program ANSYS
E.: work on Sun workstations, operating system based on Linux, Introduction to ANSYS CFX
2. L.: Coordinate system, the Navier-Stokes equations (laminar flow), counting rules, examples, flow in tube, creation of geometry in the ANSYS Workbench, principle of creation computational area and modification of geometry, creation of computational grid, process in creation grid. Demonstration of grid in program ICEM.
E.: Creation of a sudden expansion geometry (step) in the ANSYS Workbench, principles of creation computational grid and modification of geometry, creation of computational grid, process in creation of grid. Exercises of modification and creation of grid on real geometry.
E.: Practice treatment geometry and creating a network on real geometry created in CAD
3. L.: The physical meaning of turbulence, methods of of modification geometry and creation of grid on real geometry created in CAD. Mathematical models of turbulence, the N-S equation, continuity equation, Reynolds stress, time averaging, Reynolds rules, Boussinesq 's hypothesis, two equation turbulence model.
E.: CFD model of flow in a sudden extension of cross-flow, laminar flow regime. import of grid, compatible grids.
4. L: Transfer of mass, momentum and heat, conduction and convection in heat transfer, determination of thermal power, thermal gradient, heat transfer coefficient, Nusselt number.
E.: Defining the CFD model of natural convection, the calculation of heat transfer coefficient and Nusselt number
5. L.: Integration of the finite volume method for one-dimensional continuity equation and momentum equations, an iterative cycle, the interpolation scheme, convergence (residuals), the definition of species-multiphase model, the cavitation model, combustion model, model of thermal radiation, definition of chemical reaction.
E.: Determination of pressure loss in the sudden expansion, the model testing the effect of turbulence on value of loss factor. Defining the boundary conditions function, measured data. Export data from the postprocessor, data analysis in EXCEL.
6. L.: Boundary conditions, conditions of input and exit, conditions of symmetry, periodic conditions, conditions on the wall, the wall heat transfer, time-dependent task. Methods of solving discretized equations, LGS solver, multigrid.
E.: Modeling of species dispersion, the Lagrangian approach, dispersion modeling of pollutants.
7. L.: Overview of turbulence models available in CFX, the zero-equational model, k- model, RNG k- model, the RSM model, the LES models, SAS, DES. Optimal choice of model, field of use of turbulence models.
E.: Modeling of species dispersion, Euler approach, multiphase mixture of water-air.
8. L.: Flow of real fluids, the law of conservation of mass, momentum and energy for compressible flow, supersonic flow, shock waves. Co- and counterflow heat exchangers of types water-water or water-air. Specify individual seminar works and discussion.
E.: Solution of individual seminar work.
9. L.: The flow of solid particles and drops, the species and their definitions. Definition of tension and buoyancy drops coefficient - solid particles. .: Special settings in CFX, multidomain simulation, paralel calculations. Integration of CFX in Workbench, the general procedure for the design and calculation of machine.
E.: Solution of individual seminar work.
Recommended or Required Reading
Required Reading:
ANSYS CFX- ANSYS CFX Release 11.0, Theory Guide, Tutorials. Southpointe: ANSYS, Inc., 2006.
BLEJCHAŘ, T. Turbulence Modelování proudění – CFX. Ostrava: VŠB-TU Ostrava, 2012. 263 s. ISBN 978-80-248-2606-6.BLEJCHAŘ, T.: Návody do cvičení „Modelování proudění“ – CFX, [Skripta].VŠB-TU Ostrava, 2008, 132 s.
ANSYS CFX- ANSYS CFX Release 11.0, Theory Guide, Tutorials. Southpointe: ANSYS, Inc., 2006.
BLEJCHAŘ, T. Turbulence Modelování proudění – CFX. Ostrava: VŠB-TU Ostrava, 2012. 263 s. ISBN 978-80-248-2606-6.BLEJCHAŘ, T.: Návody do cvičení „Modelování proudění“ – CFX, [Skripta].VŠB-TU Ostrava, 2008, 132 s.
Recommended Reading:
Incropera, F. a kol. Fundamentals of Heat and Mass Transfer, 6. edition, John Wiley and Sons 2007, 996p., ISBN 978-0-471-45728-2.
Nikolay I. Kolev. Multiphase flow dynamics. 1, Fundamentals / - 2nd ed. Berlin : Springer, c2005 - xxxv, 753 s. : il. + 1 CD-ROM ISBN 3-540-22106-9.
Incropera, F. a kol. Fundamentals of Heat and Mass Transfer, 6. edition, John Wiley and Sons 2007, 996p., ISBN 978-0-471-45728-2.
Nikolay I. Kolev. Multiphase flow dynamics. 1, Fundamentals / - 2nd ed. Berlin : Springer, c2005 - xxxv, 753 s. : il. + 1 CD-ROM ISBN 3-540-22106-9.
Planned learning activities and teaching methods
Lectures, Tutorials
Assesment methods and criteria
Task TitleTask TypeMaximum Number of Points
(Act. for Subtasks)
Minimum Number of Points for Task Passing
Exercises evaluation and ExaminationCredit and Examination100 (100)51
        Exercises evaluationCredit35 25
        ExaminationExamination65 20