School of Engineering. Department of Mechanical and Aeronautical Engineering. Study Guide COMPUTATIONAL FLUID DYNAMICS (MKM411)

Transcription

1 School of Engineering Department of Mechanical and Aeronautical Engineering Study Guide COMPUTATIONAL FLUID DYNAMICS (MKM411) Lecturer: Dr. Mohsen Sharifpur Last Revision: January 21 st 2016 Copyright reserved 1

2 Contents 1 Welcome 3 2 General premise and educational approach 3 3 Lecturer, venues and consulting hours Lecturer Teaching assistants Consulting hours Study materials Prescribed text Prescribed software Learning activities Contact time and learning hours Homework assignments Training CFD software workshops Tutorial sessions unannounced class tests Rules of assessment Pass requirements Calculation of final mark Calculation of semester mark General Module changes Submitting of assignments Web site Assessment matrix for ECSA exit level outcome Lecture and module structure 9 2

3 1 Welcome ORGANIZATIONAL COMPONENT The Department of Mechanical and Aeronautical Engineering welcomes you to this module of Computational Fluid Dynamics (MKM411). The aim of this study guide is to direct your learning. It is a guide to what we expect of you and what we want you to achieve during the course of this module. It also gives an overview of how this module fits into your learning programme. This study guide is a crucial part of the general study guide of the Department. In the study guide of the Department, information is given on the mission and vision of the department, general administration and regulations (professionalism and integrity, course related information and formal communication, workshop use and safety, plagiarism, class representative duties, sick test and sick exam guidelines, vacation work, appeal process and adjustment of marks, university regulations, frequently asked questions), ECSA outcomes and ECSA exit level outcomes, ECSA knowledge areas, CDIO, new curriculum and assessment of cognitive levels. It is expected that you are very familiar with the content of the Departmental Study Guide. It is available in English and Afrikaans on the Department s website. English: Afrikaans: zp77599.pdf Take note of the specific instructions in the above study guide on: a. Safety b. Plagiarism c. What to do if you were sick (very important)? d. Appeal process on the adjustment of marks 2 General premise and educational approach This course aims to expose you to numerical techniques to solve computational fluid dynamics problems in thermal-fluid science, in particular, the problems which described by systems of partial deferential equations (PDEs). Recall from Physics, Deferential Equations, Thermofluids and Solid Mechanics (MKM321) that many phenomena are to easier describe when the changes of a system are considered. As you are well aware from Solid Mechanics (MKM321) many problems in engineering are described by PDEs e.g. the structural mechanics boundary value problem and the fluid dynamics initial and boundary value problem. You have already solved or approximated these problems analytically on simple geometries and under simplified assumptions in structural mechanics and thermal-fluid problems. This course opens the door to approximate these problems more generally for complicated geometries. 3

4 In this module we study two mayor numerical techniques to solve systems of partial differential equations (PDEs). Namely, they are finite difference and finite volume techniques. Each of these techniques solves systems of partial differential equations; however, finite volume techniques are used extensively in computational fluid dynamics whereas the finite element techniques which you experienced in Solid Mechanics (MKM321) are used extensively in solid mechanics applications. The focus of this course will be on the finite volume methods. PDEs are complicated problems to solve and this course will systematically change a system of PDEs into a system of algebraic equations i.e. linear algebra equations. We will do so by first discretizing the spatial domain (space) and/or temporal (time) domain into a grid or mesh. We will then discretize the continuous PDEs into a discrete set of equations which would produce a system of algebraic system of equations AX = U, which is essentially the same as a system of Linear Algebra equations that you studied in Numerical Methods (WTW263). Up to this point the system of algebraic equations cannot be solved as the system is singular. To obtain a system of algebraic equations that we can be solved, we will apply boundary and initial conditions. In addition, we will know how to convert a nonlinear equation into liner one and then solve the system of algebraic equations using various techniques developed in Linear Algebra. Next, we will do post-processing on the solution to extract quantities of interest of the engineering problem. Before, we are done we will verify the solutions against analytical solutions to ensure that we solve the equations correctly. Finally, we can validate the solutions against experimental data to see whether the equations we solved correctly are appropriate to capture the actual physics we want to model. To obtain the system of algebraic equations we will consider two foundation blocks of computational mechanics; namely, the finite difference method (FDM) and finite volume method (FVM) with the focus on the latter one. Please note that these are not the only two methods available to solve computational fluid dynamics problems, there are many more namely, finite element methods, boundary element methods, spectral element methods, analytic element method, and boundary integral element method to name a few. The FVM we consider in this course form the foundation of commercial software packages to numerically approximate solutions to engineering problems that are described by systems of partial differential equations. This course will also expose you to commercial CFD packages via semester project as well as supporting training workshops. Arrangements for the workshops will also be communicated in class as well as ClickUP. Some of the homework problems may require programming as well. 3 Lecturer and consulting hours 3.1 Lecturer Dr. Mohsen Sharifpur Eng. III, Office No.: 6-85 Tel: mohsen.sharifpur@up.ac.za 3.2 Teaching assistants Information regarding the teaching assistants will be made available on ClickUP. 4

5 3.3 Consulting hours Consulting hours for both lecturers and teaching assistant(s) will be made available on ClickUP. In exceptional circumstances; you may make an appointment outside these times. Such appointments should preferably be made directly after class or by . Should you have a problem with the mathematics associated with the course, or one of the assignment problems, you are only entitled to receive help if you can show your own attempted solution to the problem. Communication regarding important issues that concern the class (e.g. work load at a given moment, etc.) should preferably be put to the lecturer by the class representative during consulting hours, or alternatively by . 4 Study materials 4.1 Prescribed text 1- An introduction to Computational Fluid Dynamics: The Finite Volume Method, Versteeg, H.K. and Malalasekera, W., Pearson Education Ltd., Heat and Mass Transfer: fundamentals & applications (SI Unit), Ҫengel, Yunus A.;Ghajar, Afshin J., McGraw-Hill (this is a prescribed book for another course ; any edition will be acceptable). Note: The lecture slides will be posted on ClickUP (after the lectures), however, the lecturer will offer some detail explanations when offering the lecture notes by the slides (which they may not be available within the slides or in the prescribed books), therefore, attending the classes strongly recommended. 4.2 Prescribed software Commercial software packages (ANSYS-FLUENT, STAR CCM+ and FLoEFD) will be made available in the computer laboratory and you should provide your semester project by using one of them. There are limited licences available for the software packages and the extensive use of the laboratories recommended. It is strongly advised to plan the usage of the facilities. Due to the server licence of these packages, the department is unable to provide you with the software for your personal computer. One of the outcomes of this course is that you are able to use CFD packages in order to solving engineering problems. The practical use of CFD packages is a required outcome in addition to the use of programming to assist you in your investigations. 5 Learning activities 5.1 Contact time and learning hours Number of lectures per week: 3 (50 minutes per lecture), which include the lecture and examples. Number of tutorials per week: 1 (50 minutes per tutorial), which will cover the weekly homework. However, the venue is booked for two hours (the first hour is tutorial and two of the assistants will be attended); therefore, you can stay and complete your homework in the next hour. 5

6 This module carries a weighting of 16 credits, indicating that on average a student should spend 160 hours, including time for preparation for tests and examinations to master the required skills. This course includes lectures, tutorials and workshops (training course) on commercial codes which contributes about 38% of the total average required time to master the skills in this course. However, each student should attend one of the CFD training courses. 5.2 Homework assignments Regular homework assignments will be handed out. Because of large number of studemts, randomly selected questions of the assignments will be graded, and will be involved in the semester mark. The assignments will be cover theoretical and programming parts of the course. Assignments must be handed in, in the first 5 minutes of the due sessions in class. Late assignments will not be accepted. In general group discussions for the assignments are encouraged unless otherwise stated. Copying of homework (partially or completely) is strictly forbidden. Copying of homework will be subject to a disciplinary hearing and all individuals (the copier(s) and the student(s) that made his/her work available for copying) involved will be awarded a mark of -100% for the assignment. The matter will be reported to the department for further decision as well. There is a semester project which must be done by using one of the available software packages (ANSYS-FLUENT, STAR CCM+ and FLoEFD). The project mark will not be involved in the semester or final mark, but ECSA outcome. 5.3 Training CFD software workshops Learners must choose one the CFD commercial package from the available packages (ANSYS-FLUENT, STAR CCM+ and FLoEFD) to do the semester project of the course. Workshops (training course) on commercial codes will be offered for CFD based commercial packages. The schedule of training courses will be made available in ClickUP. Each student should attend one of the CFD training courses. 5.4 Tutorial sessions Weekly tutorial sessions will be held that will cover the weekly homework except for the first week of lectures. Homework will be made available on the course homepage on ClickUP. Homework must be handed in at the first 5 minutes of the due session in class. 5.5 Unannounced class tests (pop quizzes) Unannounced class tests will be taken during lectures which will also count towards your semester mark. The unannounced tests count 10% of the semester mark; however, one of the lowest unannounced tests will be dropped. There will not be any make-up for the unannounced tests; therefore, the students which attend the class will get the benefit of the unannounced class tests. On the other hand these unannounced class tests shows randomly whom attended the class regularly. 6

7 6 Rules of assessment Also see the examination regulations in the Year Books of the Faculty of Engineering, Built Environment and Information Technology (Part 1: Engineering). 6.1 Pass requirements: In order to pass this module a student must; 1. Obtain a final mark of at least 50%, 2. Obtain a mark of at least 50% for the ECSA assessment matrix on exit level outcome 5 (regarding the table which is allocated in the page 8) 6.2 Calculation of final mark: Semester mark 50% Examination mark (final exam) 50% 6.3 Calculation of semester mark: Semester test 1 40% Semester test 2 40% Assignments 10% Unannounced class tests 10% 7 General 7.1 Module changes While every effort has been made to ensure that this manual is correct, it is unavoidable that changes to both the organization and content of this module might be required from time to time. Hence this manual is subject to change by means of announcements in class and/or announcements posted on ClickUP. You will receive the important announcements by as well; therefore, it is the responsibility of the students to check if their is active on the ClickUP. However, it is recommended to check the ClickUP for announcements too. 7.2 Submitting of assignments Assignments must be handed in, in the first 5 minutes of the due sessions. Late assignments will not be accepted. 7.3 Web site Course material, lecture slides, project and assignments will be made available on ClickUP. The lecture slides will be posted on ClickUP (after the lectures), however, the lecturer will offer some detail explanations when offering the lecture notes by the slides (which they may not be available within the slides or in the prescribed books), therefore, attending the classes strongly recommended. 7

8 8 Assessment matrix for ECSA exit level outcome 5 Computational Fluid Dynamics (MKM411) Student number: Performance on the exit level outcome is deemed to be satisfactory where a student obtains a minimum of 50% on the assessment matrix, with the following weighted criteria; Description Reference Minimum threshold Able to apply verification and validation to an Homework engineering problem (15%) Comprehensive threshold Mark Able to list and apply the various steps in a computational fluid dynamics simulation (15%) Semester tests Able to analysis, solve and post processing an engineering problem using a commercial computational fluid dynamics package (70%) Semester Project Final Mark* *Subminimum of 50% required in order to achieve the exit level outcome. Assessment regarding ECSA exit level outcome 5 Pass Fail 8

9 9 Lecture and module structure Study theme and Study units Conservation laws, Initial and Boundary Conditions Mathematics review Fluid Motion Heat Transfer linear and nonlinear problems Finite Difference Method (FDM) Proper Differential Equation Discretization of the Domain Algebraic equations instead of differential Eq Boundary Nodes Finite Differences Solution Finite Volume Method (FVM) Basic Methodology Discretization of the Domain Integrate the DE over the CV s Approximate the integral Assembling the discrete system Solve iteratively or simultaneously Diffusion and convective Problems Central difference, upwind & QUICK methods Staggered arrangement Pressure-velocity coupled problems CFD Software Training Demonstrations of the packages Modelling Meshing Applying boundary conditions Processing Post processing Mode of instruction Lectures Problem in class Self-study Lectures Problem in class Programing Self-study Lectures Problem in class Computer lab Project Self-study Presentation Training workshop Computer lab Project Self-study Learning hours Contact session; estimated Total