338-0527/01 – Turbulence (Turbu)
| Gurantor department | Department of Hydromechanics and Hydraulic Equipment | Credits | 4 |
| Subject guarantor | doc. Ing. Marian Bojko, Ph.D. | Subject version guarantor | doc. Ing. Marian Bojko, Ph.D. |
| Study level | undergraduate or graduate | Requirement | Choice-compulsory |
| Year | 2 | Semester | winter |
| | Study language | Czech |
| Year of introduction | 2004/2005 | Year of cancellation | 2020/2021 |
| Intended for the faculties | FS | Intended for study types | Follow-up Master |
Subject aims expressed by acquired skills and competences
Students will become familiar with the possibilities of simulation of turbulent flow of fluids in various fields of engineering, civil engineering, aviation, metallurgy and other areas where there are equipment and machinery, which contain liquid. They create 2D and 3D CFD models of real devices in an ANSYS-Fluent. 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 solve the CFD simulation by different models of turbulence in applications of airflow around the body, heat transfer, the interaction of two different fluids. Students will interpret the results of simulations and analyse the flow.
Teaching methods
Lectures
Tutorials
Summary
The subject is focused on modeling possibilities of turbulent 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. The finite volume method (MKO) will be used to solve the system of flow equations. They will be created during the lessons 2D and 3D CFD models of real equipment in ANSYS Fluent. In the course of education, the program DesignModeler will be used to create geometry and the program ANSYS Meshing will be used to create a computational grid.
Compulsory literature:
Recommended literature:
Way of continuous check of knowledge in the course of semester
seminar work and oral examination
E-learning
no
Other requirements
At least 70% attendance at the exercises. Absence, up to a maximum of 30%, must be excused and the apology must be accepted by the teacher (the teacher decides to recognize the reason for the excuse)..
Prerequisities
Subject has no prerequisities.
Co-requisities
Subject has no co-requisities.
Subject syllabus:
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 with sudden expansion section
E.: Creation of a sudden expansion geometry (step) in the ANSYS Workbench environment, principles of calculation and adjustment of the geometry, a computer grid, the process of gridworking. Demonstration of gridworking in the program ICEM
3. L.: The physical meaning of turbulence
E.: Practice treatment geometry and creating a network on real geometry created in CAD
4. L.: 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..
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.
E.: Evaluation of laminar flow simulation result of the sudden expansion. Create a file for a post-processor evaluation
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
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.
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, the Lagrangian approach, dispersion modeling of pollutants
8. L.: Flow of real fluids, the law of conservation of mass, momentum and energy for compressible flow, supersonic flow, shock waves
E.: Modeling of flow in a rotating machine (centrifugal pump, turbine), definition of periodic conditions and the interface between moving and stationary elements
9. L.: The flow of solid particles and drops, the species and their definitions. Definition of tension and buoyancy drops coefficient - solid particles.
E.: Modeling of species dispersion, Euler approach, multiphase mixture of water-air
10. L.: Model of combustion, thermal radiation model, the definition of chemical reactions
E.: Modeling the heat transfer and heat conduction in the solid wall, a model of radiation.
11. L.: Methods of solving discretized equations, LGS solver, multigrid.
E.: Example of calculating the combined CFD-FEM, called FSI (Fluid-Solid Interaction), heat and pressure field transfer in the FEM calculation
12. L.: Specify individual seminar works and discussion
E.: Solution individual seminar work
13. L.: Special settings in CFX, multidomain simulation, paralel calculations
E.: Solution individual seminar work
14. L.: Integration of CFX in Workbench, the general procedure for the design and calculation of machine parts
E.: Solution individual seminar work
Conditions for subject completion
Occurrence in study plans
Occurrence in special blocks
Assessment of instruction