Table of Contents
What is the need for grid generation?
Numerical grid generation is the crucial initial step involved in computing numerical solutions to the equations that describe a physical process. The accuracy of the solution depends upon the quality of the grid generated.
What is grid mesh in CFD?
Grid/Mesh A mesh divides a geometry into many elements. These are used by the CFD solver to construct control volumes.
What is grid in Ansys?
Mesh or grid is defined as a discrete cell or elements into which the domain/ model is divided. All the flow variables & any other variables are solved at centres of these discrete cells. This entire process of breaking up a physical domain into smaller sub-domains (elements/ cells) is called as mesh generation.
What is adaptive grid generation?
A review of adaptive grid generation is presented with an emphasis on the basic concepts and the interrelationship between the various methods. The concepts are developed in a multifaceted progressive sense with enough detail so as to instill an operative spirit for the methods.
What are grid points?
1 (Grid Points) A grid point is the point at the intersection between the equidistant interlocking perpendicular, vertical and horizontal axes. Definition 2.1. 2 (Square Grid) A square grid is the set of grid points on a two-dimensional grid in which the number of points in every x and y axes are equal. Definition 2.1.
What is elliptic grid generation?
An elliptic grid generation method is presented to generate boundary conforming grids in domains in 2D and 3D physical space and on minimal surfaces and parametrized surfaces in 3D physical space. The elliptic grid generation method is based on the use of a composite mapping.
What is T grid meshing?
TGrid is unstructured grid generation program to create unstructured tetrahedral and Hex Core mesh for complex and very large surface mesh & capable of handling the grids of tetrahedral, hexahedral, prismatic, or pyramidal cells.
What is grid convergence in CFD?
The examination of the spatial convergence of a simulation is a straight-forward method for determining the ordered discretization error in a CFD simulation. The method involves performing the simulation on two or more successively finer grids.
What are zonal grids?
Explanation: While dealing with a complex problem, grids are generated separately for different zones which are called zonal grids. These are then attached together to form grids for the whole domain.
What is mesh size in CFD?
Co = v * dt / dx, where v is your maximum velocity in the domain, dt is your time step (defined in solver), and dx is your typical mesh size. This number should be close to 1 to ensure accuracy and numerical stability.
What is sliding mesh in CFD?
The sliding mesh model is the most accurate method for simulating flows in multiple moving reference frames, but also the most computationally demanding. Most often, the unsteady solution that is sought in a sliding mesh simulation is time periodic.
What are cells in CFD?
There are four basic 3D cell types for meshing in CFD, which are: tetrahedral, pyramidal, prismatic and hexahedral cells (shown in Figure 3). Careful selection of appropriate cell types is important for both computational power and accuracy of the results. …
What is grid refinement ratio?
The grid refinement ratio should be a minimum of r >= 1.1 to allow the discretization error to be differentiated from other error sources (iterative convergence errors, computer round-off, etc…).
What is grid independence test?
The grid independence test is a process used to find the optimal grid condition that has the smallest number of grids without generating a difference in the numerical results based on the evaluation of various grid conditions.
What is grid method used for?
The grid method is a written method used to teach children multiplication. It involves partitioning numbers into tens and units before they are multiplied. In some schools the grid method is referred to as the box method of multiplication because children learn to partition numbers into a grid of boxes.
What is the meaning of grid computing?
Grid computing is a group of networked computers which work together as a virtual supercomputer to perform large tasks, such as analysing huge sets of data or weather modeling.
What are the applications of grid generation in physics?
They have applications in the fields of computational fluid dynamics (CFD), geography, designing and many more places where numerical solutions to the partial differential equations (PDEs) are required. Numerical grid generation is the crucial initial step involved in computing numerical solutions to the equations that describe a physical process.
What is Cartesian grid in CFD?
Cartesian grid means that the entire set of discrete cells that we will be using in order to fill the CFD space are aligned along the orthogonal axis, i.e. alignment along the x, y & z axis. eg. as below : Cartesian mesh generation example
What is numerical grid generation?
Numerical grid generation is the crucial initial step involved in computing numerical solutions to the equations that describe a physical process. The accuracy of the solution depends upon the quality of the grid generated.
How does grid generation affect the accuracy of solution?
The accuracy of the solution depends upon the quality of the grid generated. A well-constructed grid can improve the quality of solution whereas, deviations from the numerical solution can be observed with a poorly constructed grid. Techniques for creating the cell forms the basis of grid generation.