Applied Computational Fluid Dynamics

Go to Course: https://www.coursera.org/learn/applied-computational-fluid-dynamics

Introduction

### Course Review: Applied Computational Fluid Dynamics In today's fast-paced technological environment, understanding Computational Fluid Dynamics (CFD) is essential for engineers and scientists alike. The "Applied Computational Fluid Dynamics" course on Coursera stands out as a highly practical and beneficial offering for those looking to deepen their knowledge and skills in this field. With comprehensive content delivered through a structured syllabus, this course is ideal for anyone interested in exploring flow physics and their applications using Simcenter STAR-CCM+ or other CFD tools. #### Overview The "Applied Computational Fluid Dynamics" course is designed for individuals looking to enhance their job performance and advance in their careers or educational pathways. It offers foundational knowledge in CFD, focusing on effectively obtaining quality solutions for complex flow and heat transfer problems. Whether you are a seasoned engineer seeking to improve your skill set or a student looking to break into the field, this course provides valuable insights and practical skills. #### Syllabus Breakdown The course is divided into five weeks, each focusing on different aspects of CFD: 1. **Introduction to Applied Computational Fluid Dynamics**: - Week 1 lays the groundwork by introducing fundamental flow models, including Euler and Navier-Stokes equations. It covers essential flow characteristics, such as boundary layers and flow separation, and explains how to visualize and analyze flow features. Techniques for enhancing simulation efficiency and estimating discretization errors are also discussed. 2. **Flows in Diffusors and Nozzles**: - Week 2 delves into the specifics of flows in diffusors and nozzles, crucial components in many engineering applications. The module emphasizes flow separation, efficiency of energy conversion, and grid dependence of solutions, enabling learners to analyze how different geometrical configurations affect flow. 3. **Secondary and Vortex Flows**: - In Week 3, students explore secondary flows induced by pressure and turbulence. This week emphasizes the physics behind these flows and offers insights into simulating them efficiently. The analysis of vortex flows provides practical applications relevant to many engineering scenarios, enhancing the course's real-world applicability. 4. **Flows Around a Circular Cylinder**: - Week 4 focuses on studying flows around a circular cylinder across various Reynolds numbers. This week's content is particularly valuable as it addresses critical phenomena like vortex shedding and drag crises. Different simulation techniques, such as large-eddy simulation or Reynolds-averaged Navier-Stokes equations, are introduced, allowing students to grasp the nuances of turbulent flow simulations. 5. **Flows with Heat Transfer**: - The final week explores heat transfer phenomena, covering conduction, natural and forced convection, and conjugate heat transfer. Understanding the intricacies of heat transfer, especially in the context of fluid-solid interfaces, is crucial for practical applications, making this module essential for aspiring engineers. #### Recommendations **Who Should Take This Course?** This course is highly recommended for: - Engineers seeking to utilize CFD in their work. - Graduate students in engineering or physics fields aiming to enhance their computational skills. - Professionals in industries such as aerospace, automotive, and energy who require an understanding of fluid flows and heat transfer. **Course Highlights**: - **Hands-On Learning**: The course involves practical exercises using CFD tools that facilitate a deeper understanding of concepts. - **Industry-Relevant Skills**: The content is geared towards real-world applications, preparing students to tackle challenges faced in various engineering sectors. - **Flexible Learning**: As an online course, students can manage their learning pace, making it suitable for working professionals. In conclusion, the "Applied Computational Fluid Dynamics" course on Coursera is a comprehensive and fruitful investment for anyone serious about mastering CFD. With its structured syllabus and practical orientation, it equips learners with critical knowledge and skills needed to solve complex fluid dynamics problems effectively. If you're looking to advance your career in this exciting and ever-evolving field, this course is well worth your time and effort.

Syllabus

Introduction to Applied Computational Fluid Dynamics

In Week 1, we'll explore flow in a channel with a semi-circular obstacle on the bottom wall is used to introduce the basic flow models (Euler, Navier-Stokes, and Reynolds-averaged Navier-Stokes equations), the basic features of most flows in engineering applications (boundary layer, shear layer, flow separation, recirculation zone), and the approaches to simulate flows including these phenomena. The distinction between inviscid, laminar, and turbulent flows is explained, as well as how the flow features can be visualized and analyzed and how the knowledge of the flow regime affects the design of the computational grid and the choice of physics models and simulation parameters. Finally, the ways of increasing the efficiency of simulation and the estimation of discretization errors are presented.

In Week 2, we'll explore flows in diffusors and nozzles are studied. They are generic representations of diverging or converging cross-sections of flow paths found in many engineering applications. In both diffusors and nozzles flow separation and recirculations occurs if diverging/converging angles are high enough. In symmetric diffusor geometries the flow is often asymmetric, and in nozzles vena contracta may occur. These phenomena and the evaluation of efficiency of energy conversion as well as the energy losses are explained. The effects of geometrical details (variation of expansion/contraction angle, rounding of corners by different radii) and suction through diffusor walls are also analyzed. Detailed studies of grid-dependence of solutions are performed and the effect of the order of discretization for convection fluxes is analyzed.

In Week 3, we'll explore pressure or turbulence induced flow in directions other than the primary flow path are studied. First three-dimensional pressure-driven secondary flows in duct or pipe bends are analyzed in detail, followed by the analysis of turbulence-driven secondary flow in ducts with non-circular cross-sections. The physics behind these phenomena is described and the ways of simulating them are explained. Next, horseshoe vortex and tip vortex flows are analyzed; they too are generic representations of flows resulting in many practical applications with body junctions and free tips. The flow physics, computational details (design of an optimal grid and its local refinement, the choice of physics models and the simulation approach) are explained.

In Week 4, we'll explore flows around a circular cylinder at Reynolds numbers between 5 and 5 million are studied. Circular cylinder is a generic representation of a slender body exposed to a cross-flow; such situations are found in many practical applications. Depending on the Reynolds number, the flow may be creeping, steady or unsteady laminar, or turbulent. The flow separation and recirculation can have many different forms, leading to vortex shedding (the von Karman vortex street), transition to turbulence in the wake, in shear layers, or in boundary layers on cylinder surface. Both the drag crises on a cylinder at the critical Reynolds number and the Magnus effect on a rotating cylinder are described. Different techniques of simulating turbulent flows - direct numerical simulation, large-eddy simulation or solution of the Reynolds-averaged Navier-Stokes equations using different turbulence models are presented and it is explained which technique is appropriate for which type of flow.

In Week 5, we'll explore heat transfer, including conduction in solids, natural and forced convection in fluids, and conjugate heat transfer. I’ll explain how the heat is transferred between continua at the solid-fluid interface, what is different in laminar and turbulent flows, which properties of a computational grid are desirable at the fluid-solid interface, and why are prism layers at walls important. The difference between stable and unstable stratification in natural convection flows and the importance of accounting for the correct dependence of fluid properties on temperature are emphasized. Finally, it is explained how to optimally simulate simultaneous heat transfer across multiple flow streams separated by solid bodies.