# CFD Labsheet Standards A description of the standard structure, standard components and standard wording used across the Ansys CFD tutorial sheets. This records what is currently done so that new sheets match existing ones. It is not a list of improvements. ## Sheet naming and scope Each sheet covers one stage of the modelling process and is titled with the topic followed by the stage in brackets. ``` Drag on a 3D sphere (Meshing) Compressible flow in a 2D nozzle (Geometry) ``` A full simulation is split across several sheets, typically Geometry, Meshing, and Solver. Each sheet must be completable on its own, starting either from work carried forward from the previous sheet or from a supplied completed project file. ## Heading levels `#` marks a stage of the modelling process. `##` marks a step within that stage. Nothing goes deeper than `##` for instructional content. Stage headings in use across existing sheets: ``` # Launch Workbench # Launch Mesher from the Workbench # Launch Fluent from the Workbench # Build the Geometry # Meshing # Preprocess the Simulation # Postprocess the Results # Finishing Up ``` Step headings are short noun or verb phrases naming the single thing that step achieves, for example `## Import point data`, `## Apply Face Meshing`, `## Set the Materials`, `## Naming the Edges`. ## Opening sequence Every sheet opens with the same three sections in the same order before the first stage heading. ### Task Overview and Information An optional overview image with caption, then a prose paragraph, then two bullet lists, then two standing lines. The prose paragraph states what is being simulated, why the geometry is set up the way it is, and what the student will go through. It runs to three or four sentences and is written in the second person future. ``` In the exercises you will simulate the flow around a sphere and extract the drag value. The dimensions are equivalent to placing a spherical object in a wind tunnel. You will go through the process of setting up the simulation (preprocessing), initialising and running the calculation, then extracting the value of drag. ``` The first list is introduced with "In this tutorial sheet, you will:" and the bullets start with a present-tense imperative verb describing an action the student takes. Five or six bullets is typical. The second list is introduced with "Stretch tasks are:" and the bullets start with a gerund. ``` Stretch tasks are: * Varying the inlet velocity to determine the relationship between Reynolds number and drag coefficient. * Performing the same process on a streamlined body and comparing the drag coefficient. ``` The section closes with two standing lines, reproduced verbatim. ``` This exercise is written for Ansys Workbench version 2025 R2. There may be minor differences if using a different version. Pre-requisite tutorials: Ansys Workbench Familiarisation ``` ### Learning Outcomes The lead-in line is always the same, followed by a learning outcomes callout. ``` ## Learning Outcomes By the end of this activity, you will be able to: !!! learning-outcomes Learning-outcomes * Practice operating the Ansys Mesher software. * Apply the concepts of mesh topology and refinement to a 3D geometry. * Use the mesh analytics tools to determine mesh quality. ``` Four outcomes is typical. They start with a verb pitched at the level of the activity, for example Practice, Understand, Apply, Use. ### Before you start Opens with the standing prerequisite line, then names what file the student needs, then the two-bullet carry-forward pattern, then the file handling callout. ``` ## Before you start Before starting this tutorial, ensure you have read the Ansys Workbench Familiarisation tutorial. You will also need to have access to a geometry file for the 3D sphere geometry. * If you have created the geometry in a previous tutorial, this can be used here. * Otherwise, download and unzip the Ansys Workbench Project file, "[filename.zip](url)", and make a note of where the files are located on your computer. ``` ## Anatomy of a step A step slide follows the same shape throughout. 1. A prose paragraph of one to three sentences saying what the step achieves and why it is being done. This is written in the first person plural, for example "In this step, we will add a Fluent component to create a simulation." or "The next step is to instruct the Mesher on the size of the quad element to use." 2. A bullet list of actions. Each bullet is one action, starts with an imperative verb, and names the full menu path. 3. Optionally a prose line describing the expected result, for example "You should now have a mapped mesh displayed on the screen." or "Your geometry should now be as shown as a grey 2D surface." 4. An image with caption. 5. Optionally a context or troubleshooting block. The prose is where the reasoning goes. The bullets stay purely procedural. ## Navigation wording Menu paths always name where the thing is before naming what to click. ``` From the [ui]File[/ui] menu at the top of the window, select [ui]Save As...[/ui] From the top icon menu, click [ui]Generate Mesh[/ui]. From the [ui]Outline[/ui] panel, right click [ui]Mesh[/ui] and select [ui]Insert[/ui] then select [ui]Face Meshing[/ui]. In the [ui]Outline[/ui] panel on the left-hand side, click [ui]Mesh[/ui] so [ui]Details of "Mesh"[/ui] appears below. ``` Where a panel is hard to find, its physical location is given in brackets. ``` In [ui]Details of "Sizing"[/ui] (at the bottom of the [ui]Outline[/ui]) In the details (at the bottom left; you may need to switch between [ui]Selection Planes[/ui] and [ui]Details[/ui]) Double click [ui]Initialization[/ui] (Under [ui]Outline view[/ui] and [ui]Solution[/ui]) ``` Standard verbs are left click, right click, double click, drag, expand, select, and click. "Under" is used for menu nesting, "In" for panels, "From" for menus. ## Inline markers `[ui]` wraps anything the student reads off the interface: menu names, button labels, panel titles, dropdown options, row names, and quoted dialogue titles such as `[ui]Details of "Mesh"[/ui]`. `[term]` wraps a technical term at the point it is first introduced, and only there. Wrap the term only, not the definition around it. ``` Ansys Mesh provides a semi-automatic tool to create near wall meshes called an [term]Inflation Layer[/term]. ``` Software names, file names and named selections the student creates are in plain text or double quotes, not wrapped. ## Images and captions Every content image has an alt text and a caption. The caption goes on the line immediately after and starts with a colon and a space. The alt text and caption are kept identical. ``` ![The Ansys Mesher showing a structured mapped mesh applied to the nozzle surface body](url) : The Ansys Mesher showing a structured mapped mesh applied to the nozzle surface body ``` Captions describe what is visible in the image rather than what the student should do. Where the image is a GIF of an interface action, the caption begins "Animation of". Images sit after the bullets they illustrate, not before. ## Context and troubleshooting blocks Two kinds of collapsible content are used, and they are distinguished by purpose. Conceptual background explaining why something is done or what a setting means is wrapped in a note callout titled "Additional Context", with the reveal nested inside it. The reveal summary is written as the question a student would ask. ``` !!! note Additional Context &&& What is curvature normal angle? The process of meshing divides up geometry into small discrete elements... ``` Troubleshooting for a student who is stuck or whose screen does not match is a standalone reveal with no callout around it. The summary states the symptom, not the question. ``` &&& If you are having trouble selecting the face. If you are having trouble picking the face in the graphics window, it could be... ``` Genuine risks that will break a later stage use a warning callout with a title stating the rule. ``` !!! warning Ensure each boundary surface has only one name The Mesher software will allow you to create more than one named selection... ``` Callout and reveal content is indented by exactly four spaces. Content nested inside a reveal inside a callout is indented by eight. ## Standard reusable blocks These appear across multiple sheets and are reproduced near-verbatim each time. ### Launching Workbench ``` * Launch Workbench by typing "workbench" on the search bar next to the windows start button, and clicking "Workbench 2025 R2" (or whatever version is installed on the computer you are using) ``` ### Opening Ansys Workbench ``` !!! note Opening Ansys Workbench &&& I don't know how to open Workbench To open Workbench on Windows, type "Workbench" into the start menu and click the version of Ansys Workbench that is installed. In the example shown here, the version is Ansys Workbench 2025 R2. ``` ### Help with file handling ``` !!! note Help with file handling &&& I don't know how to unzip a file Workbench saves "projects" on the file system with a single file, called a project file (with extension .wbpj), and a directory (aka folder) of the same name with "_files" appended to the name. In order to transfer files between people and computers, both the project file and associated folder have to be moved together and remain in the same location relative to one another. This is why when files are transferred, they are "zipped" (or "compressed") into a single package. ``` ### Help with interface ``` !!! note Help with interface &&& I've changed the layout of the workbench interface The software interface is very customisable, as different users prefer their menus in different locations. These instructions have been written assuming the default (uncustomised) interface is being used. If you have closed or undocked menus or side panels, this will make following these instructions more challenging. To restore the Ansys Workbench interface to the default layout, select [ui]View[/ui] from the top menu and try [ui]Reset Workspace[/ui] or [ui]Reset Window Layout[/ui]. ``` ### Wrong geometry software ``` &&& If the software interface doesn't look right. If instructions described here don't match what you are seeing on your screen, it is possible you have opened a different piece of Geometry creation software. Workbench comes with a number of Geometry creation tools, all of which can be used to achieve the same task. These instructions are written specifically for "DesignModeler". If you have opened another geometry creation tool, such as "Discovery" or "SpaceClaim" then these instructions will not match. Close down the Geometry creation tool you have opened and return to Workbench. Follow the previous instructions to open DesignModeler. ``` ### Selection tool trouble ``` &&& If you are having trouble selecting the face. If you are having trouble picking the face in the graphics window, it could be because the "picker" is selecting point or line elements, rather than the 2D face. You can force the software to only select certain types of geometry using the selection tool. ``` ## Closing sequence Each sheet ends with a save and close step, then a summary. ### Save your work and close ``` ## Save your work and close Mesher Finally, save your work, close down Mesher and return to Workbench for the next stage of the process: Solver Setup. * From the menu at the top of the window, click [ui]File[/ui] and [ui]Save Project[/ui] * From the menu at the top of the window, click [ui]File[/ui] and [ui]Close Meshing[/ui] * Return to Workbench ``` Where the sheet is the last in a sequence, this is instead headed `# Finishing Up` with a `## Save Your work` step, and closes with a line noting the process can be repeated on the other geometry. ### Summary The lead-in line is fixed, and the bullets start with a present-tense verb. ``` ## Summary Congratulations on reaching the end of this tutorial. In summary, you have learned to: * Open an Ansys Workbench project file and add a Fluent component connected to an existing mesh. * Configure the physical models, selecting a pressure-based steady solver and a k-epsilon turbulence model. ``` The number of bullets tracks the length of the sheet, from five or six for a short geometry sheet up to ten for a full solver sheet. Each bullet corresponds to a step or a small group of steps, in the order they appear. ## Tone and register Framing prose uses "we", for example "In this step, we will add a mesh using the default settings." Instructions use "you" or a bare imperative. Reassurance is given plainly wherever a student is likely to think something has gone wrong. The standing phrasings are "do not worry about this", "This is not an error", and "If you go over or under, do not worry". Reflective prompts are left as plain prose rather than being made into interactive blocks, and are placed after the step they relate to. ``` Can you think, looking at the shape of this element, why it is low quality? In your judgement, is this a problem? How does changing this setting change the mesh? ``` Where a student is asked to experiment, the sheet gives the specific values to try and says what to observe. ``` * Experiment with changing the [ui]Curvature Normal Angle[/ui]. Try using values of 18 degrees, 12 degrees and 8 degrees, clicking [ui]Generate[/ui] each time. Observe the change to the mesh you are creating. ``` ## Equations Equations use the block syntax opening with `$$$`, with the LaTeX on the following line indented by four spaces. There is no closing delimiter. Nomenclature follows in prose immediately after the block, in a single sentence naming each symbol with its units in brackets. ``` $$$ Re = \frac{\rho u L}{\mu} where $Re$ is the dimensionless Reynolds number (-), $L$ is the characteristic length scale of the body (m); for a sphere this is the diameter and $\mu$ is the dynamic viscosity of the fluid (Pa·s) ``` Inline variables use single dollar signs throughout, including in the nomenclature sentence.