July 28, 2020
With Show Advanced Options enabled, you have the ability to choose certain convergence criteria, which provides you with alternative ways to check convergence when using the iterative transient solver. The various convergence criteria can be selected in the Residual Monitors dialog box from the Convergence Criterion drop-down list.
Four options are available for checking an equation for convergence:
This is the default. For steady-state cases, absolute and none are the only options available for selection. The residual (scaled and/or normalized) of an equation at an iteration is compared with a user-specified value. If the residual is less than the user-specified value, that equation is deemed to have converged for a time step.
The residual of an equation at an iteration of a time step is compared with the residual at the start of the time step. If the ratio of the two residuals is less than a user-specified value, that equation is deemed to have converged for a time step.
relative or absolute
If either the absolute convergence criterion or the relative convergence criterion is met, the equation is considered converged.
The Relative Criteria can be set when relative or relative or absolute is selected.
Convergence checking is disabled.
In many situations, the absolute convergence criterion could be too stringent for transient flows causing a large number of iterations per time step. For example, the scaling of the continuity equation is based on the value of the continuity residual in the first five iterations. The scaling factor could be low if the initial continuity residual is small and therefore the scaled residual could fail to meet the absolute convergence criterion. With the relative convergence criterion, convergence is checked by comparing the residual at an iteration of a time step with the residual at the beginning of the time step and hence this problem is alleviated. The relative or absolute convergence criterion is useful in situations where the residuals of some of the equations are already very low at the start of a time step (for example, when a particular variable has reached steady-state), and the order of magnitude reduction in residuals is not possible. The none option allows you to disable convergence checking by selecting the option in the Convergence Criterion drop-down list.
In this tutorial, you will learn how to configure your simulation with the Convection and analyze the convergence criteria to obtain accurate results
The NACA four-digit wing sections define the profile by:
First digit describing maximum camber as percentage of the chord.
Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord.
OpenFOAM is the free, open source CFD software developed primarily by OpenCFD Ltd since 2004. It has a large user base across most areas of engineering and science, from both commercial and academic organisations.
In this tutorial, you will learn how to simulate a porous media using Ansys Fluent. In the first part, you can create the geometry and the mesh and the second part Ansys Fluent setup.
In this tutorial, you will learn how to simulate an Elbow 3d using Ansys Fluent, This is a basic tutorial and you can use Ansys Student version.
In this tutorial, you will learn how simulate heat transfer between plates with different solid materials. In addition to this, you will learn how to create an interface using Ansys Fluent.
In this tutorial, you will learn how to generate an XY Plot and save its picture (Post-Processing) using Ansys Fluent.
In this video, you will learn how to calculate the values of pressure, speed, temperature, and mass flow of a simulation.
You can set the Use Automatic Inflation control so that inflation boundaries are selected automatically depending on whether or not they are members of Named Selections groups.
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