# Ansys Gambit

### Overview

GAMBIT is geometry and mesh generation software, usually used with FLUENT. GAMBIT's single interface for geometry creation and meshing brings together most of FLUENT's preprocessing technologies in one environment. GAMBIT’s combination of CAD interoperability, geometry cleanup, decomposition and meshing tools results in one of the easiest, fastest, and most straightforward preprocessing paths from CAD to quality CFD mesh. Complex models can be built directly within GAMBIT’s solid geometry modeler or imported from any CAD modeler. Using a virtual geometry overlay and advanced cleanup tools, imported geometries are quickly converted into suitable flow domains. A comprehensive set of highly-automated and size function driven meshing tools ensures that the best mesh can be generated, whether structured, multiblock, unstructured or hybrid.

#### Recommended background

The course assumes you have no prior experience of working with any CFD package, although a background in engineering/physics is assumed. Participants having knowledge of fluid mechanics and numerical methods would get extra advantage. If you have any difficulty understanding any explained concept in the course, please raise your query and we would help you.

#### Your Learning

Our main objective of the course is to introduce you to the software - GAMBIT and give necessary start point for you to learn this software. You will understand the basic concepts and all the operational knowledge of geometry modeling in GAMBIT. After the course, you will be familiar with the user interfaces of the software and know how to construct a demanding geometry.

This is a free course which contains video lessons. The course is targeted towards understanding the basic features of the GAMBIT software and progressing towards the geometry modeling procedure up to face creation. The slope of the learning is maintained linear in order to build a strong software knowledge base.

##### Course Format

This course contains videos lessons. The length of video varies from 35 minutes to 70 minutes. This video lesson series covers the step by step procedure of basic geometry creation operations. Considering the number of concepts covered in each video lesson and required background study that you need to do, it is expected to finish this course in 4 weeks.

##### Course Syllabus

The course is divided into twelve lessons. Each lesson has a specific objective and is designed to satisfy the needs of subsequent lesson. It is recommended that you do not move to the next lesson until all the concepts in the lesson are well understood.

**Lesson 1: ****An Introduction to GAMBIT GUI**

In this lesson, we are going to have a look at GAMBIT GUI, what are the mouse operations available in GAMBIT and where the buttons are located. Purpose of this lesson is to describe general form of GAMBIT startup commands, the organizational structure of the files, GAMBIT directory structure and GAMBIT GUI.

This lesson gives an essence of general sequence operations in GAMBIT such as initial setup, geometry creation, meshing, mesh examination, etc.

**Lesson 2: ****General Operations – Part 1**

General operations of modeling in GAMBIT are discussed in this lesson. Basic objective of modeling is to create and mesh the fluid region for flow problems & solid regions for heat transfer. Those who are first time users of this software will be able to learn about how to use co-ordinate system, co-ordinate system operations, coloring entity by entity type or connectivity. An introduction to real, virtual and faceted geometry is included here. How to display grid, display ruler, general operations like labeling is also discussed here.

**Lesson 3: ****General Operations – Part 2**

In this lesson, one of the general operation i.e., move/copy is discussed in more details. Various options available with move/copy operation like translate, rotate, reflect and scale are discussed in details. This chapter also covers connect/disconnect operation. The use of certain miscellaneous operations such as summarize, check, modify color, change label is demonstrated here. The query operation is useful to associate geometric objects with object names. While check operation checks for valid ACIS geometry.

**Lesson 4: ****Virtual Geometry – Part 1**

Virtual geometry operation provides very convenient and powerful means of controlling the shape & controlling density of the mesh in localized regions of the model. Hence, in the study of GAMBIT, the study of virtual geometry is important. This lesson is dedicated to the virtual geometry operations. It covers following: fundamentals about entities, difference between real and virtual operations, basic tasks involving real geometry, model foreground and background as well as virtual entity categories.

**Lesson 5: ****Virtual Geometry – Part 2**

This is the second part of the lesson on virtual geometry. Virtual geometry operations include low level operations & high level operations. Low level operations such as merge, split, connect and construct along with their rules and restrictions are discussed here. The high level operations being collapse and T-connect operation. Virtual geometry applications such as cleanup imported geometry, simplify geometry, decompose geometry and adjust mesh are also covered in this topic.

**Lesson 6: ****Vertex Creation Operations**

Here, we are going to have a look at basic level geometry creation operation in GAMBIT i.e., vertex creation. GAMBIT uses the ACIS geometry engine. There are two main approaches in GAMBIT for geometry creation, those are - bottom-up and top-down approach. Here, all the vertex related operations are explained in details, which are – vertex creation, slide virtual vertex, connect/disconnect, move/copy operation, modify vertex color/label, convert vertices (non-real to real). At the last, the miscellaneous vertex operations are described.

**Lesson 7: ****Edge Creation Operations – Part 1**

The objective of this lesson is to introduce you with various edge creation operations. Edge creation operation depends on followings – number of vertices to be used in constructing the edge and the method by which the edge is created. With that perspective, this lesson contains following sections – Edge creation by vertices (straight line or projected on curved surfaces), arcs, circles, ellipses, conics, fillets, and NURBS creation. Edge creation from NURBS is possible by two methods, i.e., interpolate and approximate. Both are discussed here.

**Lesson 8: ****Edge Creation Operations – Part 2**

This is the second part of the lesson on edge creation operation. Edge creation operation using options like sweep vertices, revolve vertices and project edges on face is explained here briefly. The different methods available while using these options, various inputs required for using these options, all is explained here with software demo. Edge related operations such as connect/ disconnect, modify edge color/ label, move/copy/align edges are also covered in this lesson.

**Lesson 9: ****Edge Creation Operations – Part 3**

This is the third part of the lesson on edge creation operation. It explains about split operation, merge operation, smooth real edges and convert edges (non-real to real). Smoothing of real edges is possible using two options. Both options employ tolerant modeling. There are limited operations available on virtual edges in GAMBIT. Hence, GAMBIT provides convert edges option to convert non-real edges to real edges, which is described here. And finally, this lesson covers the miscellaneous operations related to edges.

**Lesson 10: ****Face Creation Operations – Part 1**

This lesson discusses about face creation using different basic operations. It speaks more specifically about face creation from wireframe; parallelogram & polygon face creation, create circular and elliptical face from vertices, and create skin surface face. The basic requirements of the face creation operations are elaborately discussed in this lesson. Skin surface face option creates a surface consisting of one or more faces from a set of "ribs". What are the type of ribs and how they affect the face creation, all is described here.

**Lesson 11: ****Face Creation Operations – Part 2**

The topic of discussion of this lesson is the face creation operations. It covers the following face creation operations- create primitive faces, Boolean operations, connect & disconnect faces, change color & modify label, move/copy faces & align face operation. Boolean operations - unite, subtract and intersect are explained here in detail. The Boolean operation is possible with two or more faces. Boolean operations fail for geometries which are failed for geometry check.

**Lesson 12: ****Face Creation Operations – Part 3**

The remaining operations under the face creation tool are explained in this lesson. The face creation operations such as splitting and merging are explained in detail. This lesson more focuses on converting faces i.e. non real to real faces. Non real faces create complexity while creating the volume; hence the operation of converting non real faces into real faces is important. Also the other operations such as topology & geometry check, summarize face and query face are also explained in this lesson.

**1. What are the prerequisites of this course?**

Course has no prerequisites but we assume that you have fundamental knowledge of Fluid mechanics and Mathematics.

**2. When I can start the course and how much time needed to complete the course?**

The course is available all the time. Time necessary to start the course is what you need to create a LearnCAx login :). Considering difficulty level, understanding capacity and necessary extra reading, on average, we expect this course to be finished in 4 weeks.

**3. What are the GAMBIT overall capabilities?**

In GAMBIT, complex models can be built directly within GAMBIT's solid geometry modeler, or imported from any CAD modeler. Advanced tools for journaling let you edit and conveniently replay model building sessions for parametric studies. Using a virtual geometry overlay and advanced cleanup tools, imported geometries are quickly converted into suitable flow domains. GAMBIT is having comprehensive set of highly-automated and size function driven meshing tools.

**4. How difficult is this course?**

The course is designed for beginners and we believe that it’s easy for everyone.

**5. I am having trouble uniting two volumes, what should I do?**

You can fix this problem by either of the following two ways-

Either you can try healing the volumes, or by deleting the volume without lower topology, healing and uniting the faces & then building the volume again.

**6. Why does GAMBIT refuse to open my .dbs file and say that my file is already open?**

Before opening your file "X.dbs", GAMBIT looks for a file named "X.lok" in the home directory to determine the status of your file. If it finds the .lok file, you'll get the error message. Deleting the .lok file should solve your problem.

**7. Where am I going to apply my knowledge of GAMBIT in actual industry?**

GAMBIT software is utilized heavily in large-scale automotive and aerospace applications, in which, the advanced meshing techniques are required for the computational analysis of fluid flow.

The GAMBIT software package is designed to help analysts and designers of automotive and aerospace industry to build and mesh models in the easiest, fastest, and most straightforward way for computational fluid dynamics (CFD) and other scientific applications. With advanced geometry and meshing tools in a powerful, flexible, tightly-integrated, and easy-to-use interface, GAMBIT can dramatically reduce preprocessing times for many applications.

**8. Will I get the software access along with this course?**

No. We don’t provide the software access.

**9. I have few queries related to work I am doing. Can I contact you? **

As the course is designed for beginners, so you might have specific questions. Feel free to ask those questions using the link “Ask a Question” given on course page.