480MI-2 - COMPUTATIONAL METHODS FOR FLUID DYNAMICS AND HEAT TRANSFER 2024

Presentation of the CFD  courses:

1. Introduction to Computational Fluid Dynamics
2. Computational methods for Fluid Dynamics and Heat Transfer

Outline

• Course objectives and aims
• To whom is it addressed?
• Requirements
• Course program
• Texts and teaching materials
• Communication methods
• Tutorials
• Homework
• Student project
• Examination method
• News & common problems

In this first introductory part, the fundamental aspects of CFD are addressed, in particular:

• What is CFD
• Areas of application of CFD
• Limits and capabilities of CFD techniques
• Historical notes
  • The beginning of CFD and CHT 
  • The evolution of CFD and CHT |
  • The rise of commercial CFD
  • The Open Source alternatives
  • Recent achievements and emerging trends
• Applications of CFD
  • Some relevant examples
• CFD components
  • CFD Ingredients
• CFD workflow
• Numerical Methods in CFD
  • Properties of numerical methods in CFD

In this second part - aimed especially at students attending only the course Introduction to Computational Fluid Dynamics - the main characteristics of the numerical methodologies commonly used in CFD are briefly illustrated.

Estratto

Fundamentals of vectors and index (tensor) notation

This document reports the Fundamentals of the Finite Difference method (FD) for Computational Fluid Dynamics (CFD) and Numerical Heat Transfer (NHT). In particular, after a general overview of the method and the presentation of the most frequent FD approximations for first and second-order derivatives, it illustrates some different techniques - Taylor series, polynomial interpolation and difference operators - which can be used to derive different schemes for the Finite Difference Equations (FDE) representative of their corresponding Partial Differential Equations (PDE).

The Finite Volume method is presented for cell-centered grids. Cartesian and generally unstructured, polyhedral grids are considered. The main contents are:

• Generalities and the basic idea
  • The computational grid
• Spatial discretization
  • The steady case: surface and volume integrals, source term
• Interpolation techniques
• Final algebraic equation
• Boundary conditions
• Temporal integration
  • Application to the generic transport equation
• Solution of the linear equation systems
  • Direct methods
  • Iterative methods
• Thermal-fluid problems
  • Rhie-Chow interpolation
• Finite volume procedure
  • Segregated methods
  • Coupled methods
• Unstructured grids
  • Geometric quantities and grid quality
  • Gradient calculation
  • Unsteady and source terms
  • Convective and diffusive fluxes
  • Initial and boundary conditions
  • Final algebraic equation
  • Data structure for cell-centered unstructured grids

Definition of Verification and Validation (V&V) accordingly to the most recent standards and guidelines.

• Descrizione e stima dell'errore nelle simulazioni CFD;
• Raccomandazioni per l'analisi dell'accuratezza di una simulazione CFD.

In questa sezione verranno riportati alcuni confronti fra i metodi numerici più diffusi in CFD qualora applicati a semplici problemi, perlopiù 1D che, in molti casi possano venir risolti manualmente.

Using MATLAB powerful sparse matrix to solve structured Cartesian 1D and 2D transport problems.

Example of MATLAB Live Script for the numerical analysis of 1D straight fins with the Finite Volume method

MATLAB PDETool Live Script for the solution of the Case 1 of the European Standard EN ISO 10211: Thermal bridges in building construction - Heat flows and surface temperatures - Detailed calculations (ISO 10211:2017)

MATLAB PDETool Live Script for the solution of the Case 2 of the European Standard EN ISO 10211: Thermal bridges in building construction - Heat flows and surface temperatures - Detailed calculations (ISO 10211:2017)

DRAFT and INCOMPLETE

Simulation of the flow in a 90° elbow with ANSYS Fluent

In this tutorial, the external aerodynamics of the Ahmed's Body is computed, using a RANS model, with Fluent. The geometry is defined directly using ANSYS SpaceClaim.

ANSYS Mesh file for the "External aerodynamics over Ahmed’s body with ANSYS Fluent"

ANSYS mesh file for the "Prediction of the thermal performance of a microchannel heat sink using ANSYS WB and Fluent"

Geometry (CAD) file of a static mixer. The mesh will be generated using the Watertight geometry workflow of ANSYS Fluent meshing.

A complete tutorial - meshing, set-up, simulation and post-processing - of a (simple) centrifugal pump by ICEM CFD 16.2 and ANSYS CFX 16.2.

All files required for the tutorial

2D differentially heated cavity with ANSYS Fluent and MATLAB

Regole e suggerimenti per lo Student Project (Tesina) di Termofluidodinamica Computazionale

Example  of Student Project

A simple, but effective, LaTeX template for the TCFD coiurse student's project

Lista elementi (connettività) di una griglia 2D

Lista dei nodi di una griglia 2D

Griglia OpenFOAM della geometria 1

Griglia OpenFOAM della geometria 2

Griglia OpenFOAM della geometria 1

Griglia OpenFOAM della geometria 2

Griglia OpenFOAM della geometria 1

Griglia OpenFOAM della geometria 2

Esercizi da svolgere (Homework) AA 2016/17

Homework 1 for AA 2018-19

Homework No. 2 for AA 2018-19

MATLAB Script for the semi-analytical solution of Homework No. 2 AA 2018/19 (courtesy of R. Zamolo)

Homework No. 3 for AA 2018-19

Coordinates of mesh nodes for grid 1 of Homework No. 3 AA. 2018-19

Coordinates of mesh nodes for grid 2 of Homework No. 3 AA. 2018-19

Cell connectivity matrix of Homework No. 3 AA. 2018-19

Homework No. 1 AA 2022-23

Homework No. 2 AA 2022-23

Node file for Homework No. 2 AA 2022-23

Element file for Homework No. 2 AA 2022-23

Seminario Dr. Benacchio 07.04.2016:

"Towards scalable numerical weather and climate prediction with mixed finite element discretizations"

Seminario P. Asinari 28.05.2018: "Fundamentals of Lattice Boltzmann Methods"