{"id":24770,"date":"2020-03-11T15:58:02","date_gmt":"2020-03-11T15:58:02","guid":{"rendered":"https:\/\/www.simscale.com\/?post_type=epkb_post_type_1&#038;p=24770"},"modified":"2025-10-30T10:30:03","modified_gmt":"2025-10-30T10:30:03","slug":"how-to-prepare-cad-for-simulating-rotating-zones","status":"publish","type":"epkb_post_type_1","link":"https:\/\/www.simscale.com\/knowledge-base\/how-to-prepare-cad-for-simulating-rotating-zones\/","title":{"rendered":"How to Prepare the CAD for Simulating Rotating Zones?"},"content":{"rendered":"\n\t\t<div id=\"eckb-article-page-container-v2\" class=\"eckb-article-page-content-counter eckb_ap_active_theme_simscale \" data-mobile_breakpoint=\"768\">    \t\t\t\t<a href=\"#eckb-article-content\" class=\"eckb-skip-link eckb-screen-reader-text\">Skip to main content<\/a>   <div id=\"eckb-article-header\" ><\/div>\n\t\t\t<div id=\"eckb-article-body\">  <div id=\"eckb-article-left-sidebar\" ><\/div>\n\t\t        <article id=\"eckb-article-content\" tabindex=\"-1\" data-article-id=\"24770\" >                        <div id=\"eckb-article-content-header-v2\" ><div id=\"eckb-article-content-header-row-3\"><div class=\"eckb-article-content-header-row-left-group\">\n\t\t<div class=\"eckb-article-content-created-date-container\">\t\t<span class=\"eckb-meta-data-feature-icon epkbfa epkbfa-calendar\"><\/span><span class=\"eckb-meta-data-feature-text\">Created On<\/span><span class=\"eckb-meta-data-feature-value\"><time class=\"entry-date\" datetime=\"2020-03-11T15:58:02+00:00\">March 11, 2020<\/time><\/span>\t\t<\/div> \n\t\t<div class=\"eckb-article-content-author-container\">\t\t<span class=\"eckb-meta-data-feature-icon epkbfa epkbfa-user\"><\/span><span class=\"eckb-meta-data-feature-text\">by<\/span><span class=\"eckb-meta-data-feature-value\">Theresa<\/span>\t\t<\/div> <\/div><\/div><\/div><div id=\"eckb-article-content-body\" >\n<p class=\"wp-block-paragraph\">When performing a simulation with rotating parts, such as pumps and turbines, we need to use rotating zones. This requires some additional steps to prepare the CAD before importing the model into the SimScale Workbench.<\/p>\n\n\n\n\n\n\n<p class=\"wp-block-paragraph\">In short, a CAD model for simulations with rotating zones needs to contain one flow volume region, and one additional volume per rotating zone. This article outlines the best practices that users should follow to prepare their CAD models.<\/p>\n\n\n\n<div class=\"hw-block hw-note hw-note--warning hw-note\">\n    <div class=\"hw-note__title\">\n        <p class=\"hw-note__titleText\"><i class=\"fa fa-exclamation-circle\" aria-hidden=\"true\"><\/i>Important<\/p>\n    <\/div>\n    <div class=\"hw-note__body\">\n        <p>It is possible to generate rotating zones in SimScale or in a CAD software. For demonstration purposes, we are going to showcase the workflows in SimScale and <a href=\"https:\/\/www.onshape.com\/en\/\" target=\"_blank\">Onshape<\/a>. (Onshape is not a part of SimScale)\r\n<br> <br> \r\nPlease note that, as far as CAD preparation goes, multiple workflows will lead you to the same result. This article does not intend to be exhaustive: it only shows one of the possible workflows.<\/p>\n    <\/div>\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"approach\">Approach<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The most important requirement when you prepare the CAD for a simulation involving rotating motion is the <strong>rotating zone:<\/strong> a cylindrical volume surrounding all rotating parts. For information regarding the setup of a rotating zone in SimScale, please visit this documentation page.<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-simscale wp-block-embed-simscale\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"i2thEPrV33\"><a href=\"https:\/\/www.simscale.com\/docs\/simulation-setup\/advanced-concepts\/rotating-zones\/\">Rotating Zones<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Rotating Zones&#8221; &#8212; SimScale\" src=\"https:\/\/www.simscale.com\/docs\/simulation-setup\/advanced-concepts\/rotating-zones\/embed\/#?secret=aTe9Exeus6#?secret=i2thEPrV33\" data-secret=\"i2thEPrV33\" width=\"500\" height=\"282\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Below, you will find examples showing the workflow to prepare the CAD model for a simulation with rotating zones for internal and external applications. Examples are a drone, a water pump, and a wind turbine.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"example-1-drone-simscale\">Example 1: Drone (SimScale)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This example features the geometry from the <a href=\"https:\/\/www.simscale.com\/docs\/tutorials\/drone-simulation-rotating-zones\/\">drone simulation tutorial<\/a>. The geometry initially contains the drone propeller and the arm. Using CAD Edit the flow volume region and the rotating zone can be created within the SimScale environment without having to leave the platform.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-access-CAD-editor.png\"><img loading=\"lazy\" decoding=\"async\" width=\"894\" height=\"919\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-access-CAD-editor.png\" alt=\"drone tutorial - access CAD editor\" class=\"wp-image-107871\" style=\"width:609px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-access-CAD-editor.png 894w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-access-CAD-editor-292x300.png 292w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-access-CAD-editor-768x789.png 768w\" sizes=\"auto, (max-width: 894px) 100vw, 894px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 1: Drone is a good example for external aerodynamics simulation involving rotating parts. This figure shows how to enter the CAD Edit environment from the SimScale Workbench.<\/figcaption><\/figure>\n<\/div>\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"145\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations-1024x145.png\" alt=\"drone tutorial - cylinder geometry primitive\" class=\"wp-image-107872\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations-1024x145.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations-300x42.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations-768x109.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations-1536x217.png 1536w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-list-of-operations.png 1914w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 2: The list of operations supported in CAD Edit. Choose <em>Cylinder<\/em> from <em>Primitives<\/em> to create rotating zones.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The <em>Primitives Cylinder<\/em> operation in <a href=\"https:\/\/www.simscale.com\/docs\/cad-preparation\/cad-mode\/\">CAD Edit<\/a> allows the creation of cylindrical volumes that can be used when dealing with simulation domains having rotating zones. There are two methods to create cylinders:&nbsp;<em>Custom<\/em>&nbsp;and&nbsp;<em>From faces<\/em>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When using the&nbsp;<em>Custom<\/em>&nbsp;method, the center of rotation, axis of rotation, radius, and height of the cylinder need to be specified by the user.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1222\" height=\"853\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder.png\" alt=\"drone tutorial - custom cylinder operation\" class=\"wp-image-107873\" style=\"width:768px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder.png 1222w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder-300x209.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder-1024x715.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-custom-cylinder-768x536.png 768w\" sizes=\"auto, (max-width: 1222px) 100vw, 1222px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 3: A preview of the cylinder is visible in the viewer before accepting the cylinder settings<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">The&nbsp;<em>Custom<\/em>&nbsp;approach requires global coordinates to be provided for the creation of the cylinder. In case you don\u2019t have those readily available, the&nbsp;<em>From faces<\/em>&nbsp;approach might be preferred.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When using the&nbsp;<em>From faces<\/em>&nbsp;approach to create a cylinder, the user needs to select the&nbsp;<em>Faces<\/em>&nbsp;which should be covered by the cylinder:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1206\" height=\"851\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces.png\" alt=\"drone tutorial - cylinder from faces\" class=\"wp-image-107875\" style=\"width:767px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces.png 1206w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces-300x212.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces-1024x723.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-Cylinder-from-Faces-768x542.png 768w\" sizes=\"auto, (max-width: 1206px) 100vw, 1206px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 4: The box selection tool, highlighted by the blue arrow, can help to quickly select the faces of interest<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">With this approach, a cylinder that envelops all selected faces is created. Furthermore, a&nbsp;<em>Clearance factor<\/em>&nbsp;is applied, ensuring that the cylinder is slightly larger than the assigned faces. For simulations involving rotating machinery, a&nbsp;<em>Clearance factor<\/em>&nbsp;of&nbsp;<strong>1.1<\/strong>&nbsp;is recommended.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As a result of the&nbsp;<em>Cylinder<\/em>&nbsp;operation, a brand new volume is created:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1533\" height=\"850\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder.png\" alt=\"drone tutorial - visualization of the created cylinder\" class=\"wp-image-107874\" style=\"width:768px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder.png 1533w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder-300x166.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder-1024x568.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/drone-tutorial-visible-cylinder-768x426.png 768w\" sizes=\"auto, (max-width: 1533px) 100vw, 1533px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 5: A new volume named&nbsp;<em>Cylinder<\/em>&nbsp;will be visible in CAD Edit after running the operation<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Creating a rotating zone using CAD Edit is suited when dealing with cylindrical rotating regions. For more complex blade shapes and orientations refer to the following examples.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"example-2-wind-turbine-simscale\">Example 2: Wind Turbine (SimScale)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In this example, a wind turbine geometry containing only the solid turbine parts is used as a starting point.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-1.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"411\" height=\"732\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-1.jpg\" alt=\"wind turbine geometry rotating zone\" class=\"wp-image-43719\" style=\"width:308px;height:549px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-1.jpg 411w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-1-168x300.jpg 168w\" sizes=\"auto, (max-width: 411px) 100vw, 411px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 6: Initial CAD model for the wind turbine, showing the rotor (1), nacelle (2), and tower (3).<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Upon bringing this model to SimScale, we can enter the <a href=\"https:\/\/www.simscale.com\/docs\/cad-preparation\/cad-mode\/\">CAD Edit<\/a> environment to perform the following operations:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Create a cylinder to represent the rotating zone<\/li>\n\n\n\n<li>Create a flow region for the external aerodynamics simulation<\/li>\n\n\n\n<li>Delete the solid parts of the wind turbine<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The blades from this geometry are at an angle. With the <em>From faces<\/em> method for the <em>Cylinder<\/em> operation, the algorithm will automatically generate a rotating zone with the correct angle:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1921\" height=\"963\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces.png\" alt=\"wind turbine - selecting the rotor faces to create a cylinder\" class=\"wp-image-107876\" style=\"width:768px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces.png 1921w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces-300x150.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces-1024x513.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces-768x385.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-cylinder-from-faces-1536x770.png 1536w\" sizes=\"auto, (max-width: 1921px) 100vw, 1921px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 7: Generating a MRF rotating zone for angled blades in the CAD Edit environment with a <em>Cylinder<\/em> operation<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">An easy way to quickly select the rotor faces is by having an explicit volume for the rotor (separate from the rest of the geometry). The result will be an angled rotating zone:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-angled-rotating-zone.png\"><img loading=\"lazy\" decoding=\"async\" width=\"434\" height=\"829\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-angled-rotating-zone.png\" alt=\"wind turbine - angled cylinder\" class=\"wp-image-107877\" style=\"width:425px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-angled-rotating-zone.png 434w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-angled-rotating-zone-157x300.png 157w\" sizes=\"auto, (max-width: 434px) 100vw, 434px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 8: <em>From faces <\/em>method for the <em>Cylinder<\/em> operation automatically adjusts the rotating zone to the angles of rotating parts.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">After creating the rotating zone volume, the next step is to generate a flow region. In this case, an <em>External Flow Volume<\/em> operation is the best option:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1653\" height=\"579\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region.png\" alt=\"wind turbine - generating a flow region geometry with rotating zone\" class=\"wp-image-108095\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region.png 1653w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region-300x105.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region-1024x359.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region-768x269.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/09\/wind-turbine-external-flow-region-1536x538.png 1536w\" sizes=\"auto, (max-width: 1653px) 100vw, 1653px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 9: A very important step is to assign the rotating zone as an <em>Excluded Part<\/em>. This will ensure a correct behavior in the simulation run.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Finally, before clicking <em>Save<\/em> to export the new geometry back to the Workbench as a copy, the solid parts (tower, nacelle, and rotor) first need to be deleted using a <em>Delete Body<\/em> operation:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1174\" height=\"564\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies.png\" alt=\"wind turbine - deleting solid parts simulation with a rotating zone cad edit\" class=\"wp-image-108096\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies.png 1174w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-300x144.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-1024x492.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-768x369.png 768w\" sizes=\"auto, (max-width: 1174px) 100vw, 1174px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 10: For analysis types such as incompressible, only the flow region and the rotating zone volume need to be in the final CAD model. Therefore, the solid parts need to be deleted.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">After deleting the solid parts, the CAD model will be correctly constructed for a simulation involving rotating zones.<\/p>\n\n\n\n<div class=\"hw-block hw-note hw-note--success hw-note\">\n    <div class=\"hw-note__title\">\n        <p class=\"hw-note__titleText\"><i class=\"fa fa-exclamation-circle\" aria-hidden=\"true\"><\/i>Did you know?<\/p>\n    <\/div>\n    <div class=\"hw-note__body\">\n        <p>In a CAD model that is correctly prepared for simulations with rotating zones, the flow region will contain the negative of the solid parts. Note that the solid parts (e.g. the rotor blades) should not be part of the final geometry.\r\n<br>\r\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Workbench-cad-mode.jpg\"><img decoding=\"async\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-only-flow-region-and-cylinder.png\" alt=\"correct cad preparation rotating zone simscale\" class=\"wp-image-43726\"\/><\/a><figcaption>Figure 11: A CAD model for a simulation with a single rotating zone should consist of a flow region and a rotating zone volume.<\/figcaption><\/figure>\r\n<\/p>\n    <\/div>\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"example-3-water-pump-onshape\">Example 3: Water Pump (Onshape)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">This example features the geometry from the water pump <a href=\"https:\/\/www.simscale.com\/docs\/tutorials\/incompressible-flow-in-centrifugal-pumps\/\">tutorial<\/a>. The initial pump model contains the rotor blade, housing, and a back cover. Water enters the pump through the front inlet and leaves through the top outlet.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Pump-Onshape.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"586\" height=\"622\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Pump-Onshape.jpg\" alt=\"prepare cad for simulating rotating zones simscale geometry before preparation\" class=\"wp-image-43737\" style=\"width:440px;height:467px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Pump-Onshape.jpg 586w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Pump-Onshape-283x300.jpg 283w\" sizes=\"auto, (max-width: 586px) 100vw, 586px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 12: Initial geometry for a water pump simulation, highlighting the rotor blades (1), housing (2) and back cover (3)<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">In the CAD tool, before importing the model to SimScale, we need to create a rotating zone around the rotor blades. Note that the rotor blades volume is centralized at the origin. This will make the next steps much easier to follow.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The first operation consists of creating a <em>Sketch<\/em>, using one of the planes at the origin. In this case, we will use the <em>Front<\/em> plane:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotor-blades.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"907\" height=\"736\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotor-blades.jpg\" alt=\"creating a sketch on onshape rotating zone\" class=\"wp-image-43727\" style=\"width:680px;height:552px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotor-blades.jpg 907w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotor-blades-300x243.jpg 300w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotor-blades-768x623.jpg 768w\" sizes=\"auto, (max-width: 907px) 100vw, 907px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 13: To make the operation easier to perform, you can only keep the rotor blades volume visible<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Now, we can use sketch tools to draw a profile for the rotating zone, which will be revolved afterward. Note that the profile should be slightly larger than the rotor in all directions. As a rule of thumb, you can make the rotating zone extend further than the blades in all directions by a distance of \\(0.05D\\), where \\(D\\) is the diameter of the blades.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"769\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch-1024x769.jpg\" alt=\"sketch cad rotating part\" class=\"wp-image-43800\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch-1024x769.jpg 1024w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch-300x225.jpg 300w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch-768x577.jpg 768w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Sketch.jpg 1114w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 14: Since we will revolve the sketched profile, we need to capture only half of the rotor blades in the sketch.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">After accepting the sketch, we are ready to use the <em>Revolve<\/em> operation to create the rotating zone volume, with the following steps:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"770\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone-1024x770.jpg\" alt=\"revolve operation mrf rotating zone\" class=\"wp-image-43799\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone-1024x770.jpg 1024w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone-300x226.jpg 300w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone-768x578.jpg 768w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Rotating-zone.jpg 1106w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 15: The revolve operation allows you to revolve a profile around an axis.<\/figcaption><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Create a <strong>&#8216;Revolve&#8217;<\/strong> operation<\/li>\n\n\n\n<li>Select the faces of the sketch as the profile to revolve<\/li>\n\n\n\n<li>The revolve axis will be the baseline of the sketch, which goes through the point (0, 0, 0)<\/li>\n\n\n\n<li>Make sure that you are creating a <strong>&#8216;New&#8217;<\/strong> volume in this operation<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">At this point, the geometry consists of 4 parts: the back cover, the housing, the rotor blades, and the rotating zone. This geometry can be imported to SimScale for further CAD preparation. To see all CAD import options, please refer to this <a href=\"https:\/\/www.simscale.com\/docs\/cad-preparation\/#cad-uploadimport\">documentation page<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"cad-mode\">CAD Edit<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The geometry is not yet ready to run a CFD simulation. We need to create a flow region, and also delete the solid parts of the domain.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Both of these operations can be performed in SimScale&#8217;s <a href=\"https:\/\/www.simscale.com\/docs\/cad-preparation\/cad-mode\/\">CAD Edit<\/a>:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1281\" height=\"749\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1.png\" alt=\"centrifugal pump - cad edit environment simscale\" class=\"wp-image-108103\" style=\"width:768px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1.png 1281w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1-300x175.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1-1024x599.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Edit-CAD-1-768x449.png 768w\" sizes=\"auto, (max-width: 1281px) 100vw, 1281px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 16: Entering the CAD Edit environment in SimScale<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Within CAD Edit, we have two main objectives:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Create an internal flow region<\/li>\n\n\n\n<li>Delete all solid parts from the geometry<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, the first step is to select an <strong>&#8216;Internal flow volume&#8217;<\/strong> operation, and follow the steps below:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1336\" height=\"875\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region.png\" alt=\"centrifugal pump - internal flow volume extraction cad edit\" class=\"wp-image-108104\" style=\"width:768px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region.png 1336w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region-300x196.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region-1024x671.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-internal-flow-region-768x503.png 768w\" sizes=\"auto, (max-width: 1336px) 100vw, 1336px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 17: By excluding the rotating zone from the operation, its volume will be ignored for the flow volume extraction operation.<\/figcaption><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Create an <strong>&#8216;Internal&#8217;<\/strong> flow volume extraction operation<\/li>\n\n\n\n<li>As <em>Seed<\/em> face, assign one internal face that will be in contact with the flow region<\/li>\n\n\n\n<li>Under <em>Boundary faces<\/em>, assign the boundary faces around the openings. Make sure to check this <a href=\"https:\/\/www.simscale.com\/knowledge-base\/flow-volume-extraction\/\">article<\/a> if you are unsure about the boundary faces of your geometry<\/li>\n\n\n\n<li>Assign the <em>Rotating Zone<\/em> volume in the <em>Excluded parts<\/em> tab<\/li>\n\n\n\n<li>Press <strong>&#8216;Apply&#8217;<\/strong> to run the operation<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">At this point, one volume named <em>Flow region<\/em> is created in the scene tree on the top right. We are now ready to delete the unnecessary parts of the geometry. <\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"532\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1-1024x532.png\" alt=\"centrifugal pump - delete body operation cad edit simscale\" class=\"wp-image-108106\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1-1024x532.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1-300x156.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1-768x399.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-Delete-bodies-1.png 1402w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 18: With this operation, we are only maintaining in the geometry the flow region and the rotating zone volumes.<\/figcaption><\/figure>\n\n\n\n<ol id=\"block-dd581ab7-8a8e-431b-b5c9-b9a25e7630c7\" class=\"wp-block-list\">\n<li>Pick the <strong>&#8216;Delete&#8217;<\/strong> operation under<em> BODY<\/em> <\/li>\n\n\n\n<li>Select the rotor blades, the housing, and the back-cover volumes. Note that two volumes remain unselected: the flow region and the rotating zone<\/li>\n\n\n\n<li>Hit <strong>&#8216;Apply&#8217;<\/strong><\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Before exporting this model to the Workbench, we can also extend the inlet and outlet faces, which is a good practice for simulations with pumps. The <em>Move face<\/em> operation can be used for this purpose:<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1665\" height=\"740\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces.png\" alt=\"centrifugal pump - save a cad model from cad edit\" class=\"wp-image-108107\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces.png 1665w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces-300x133.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces-1024x455.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces-768x341.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-move-faces-1536x683.png 1536w\" sizes=\"auto, (max-width: 1665px) 100vw, 1665px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 19: Once you hit <em>Save<\/em>, the current state of the geometry in the CAD Edit is exported to the Workbench.<\/figcaption><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Select a <strong>&#8216;Move&#8217;<\/strong> operation<\/li>\n\n\n\n<li>Select inlet and outlet faces<\/li>\n\n\n\n<li>Set the <em>Move method<\/em> to <strong>&#8216;Distance&#8217;<\/strong>, with an appropriate <em>Distance<\/em> of interest<\/li>\n\n\n\n<li>Hit <strong>&#8216;Apply&#8217;<\/strong> to run the operation<\/li>\n\n\n\n<li>Click on <strong>&#8216;Save&#8217;<\/strong> to export the model to your Workbench<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">This geometry is correctly constructed for simulations with rotating zones in SimScale.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-ready-for-simulation.png\"><img loading=\"lazy\" decoding=\"async\" width=\"627\" height=\"629\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-ready-for-simulation.png\" alt=\"centrifugal pump - geometry ready for simulations with rotating zones\" class=\"wp-image-108108\" style=\"width:494px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-ready-for-simulation.png 627w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-ready-for-simulation-300x300.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/centrifugal-pump-ready-for-simulation-150x150.png 150w\" sizes=\"auto, (max-width: 627px) 100vw, 627px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 20: Correctly constructed geometry for simulations with rotating zones, containing a flow region and a rotating zone volume<\/figcaption><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\" id=\"example-4-wind-turbine-onshape\">Example 4: Wind Turbine (Onshape)<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In this external aerodynamics example, the same wind turbine model will be used, but this time the MRF rotating zone will be constructed in Onshape.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The easiest way to prepare the CAD model is by sketching a cylinder, which will be used to construct the rotating zone:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"621\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch-1024x621.jpg\" alt=\"wind turbine mrf creation\" class=\"wp-image-43720\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch-1024x621.jpg 1024w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch-300x182.jpg 300w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch-768x466.jpg 768w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-sketch.jpg 1160w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 21: Note that the sketched circle is slightly larger than the diameter of the blades.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">After creating the initial sketch, we are ready to extrude the MRF rotating zone as a new part. In this step, it&#8217;s important that the rotating zone fully envelops the rotating parts:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-rotating-zone.jpg\"><img loading=\"lazy\" decoding=\"async\" width=\"806\" height=\"713\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-rotating-zone.jpg\" alt=\"mrf creation external aerodynamics\" class=\"wp-image-43721\" style=\"width:605px;height:535px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-rotating-zone.jpg 806w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-rotating-zone-300x265.jpg 300w, https:\/\/frontend-assets.simscale.com\/media\/2021\/03\/Wind-turbine-rotating-zone-768x679.jpg 768w\" sizes=\"auto, (max-width: 806px) 100vw, 806px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 22: Notice that the rotating zone volume is always created as a <strong>New<\/strong> volume.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">At this point, you can rename the rotating zone volume appropriately, and the model is ready to import to SimScale.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"cad-mode\">CAD Edit<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Once in SimScale, it&#8217;s necessary to perform a couple of operations before using the geometry for a simulation. The objectives from this stage are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Generating the flow domain for the simulation<\/li>\n\n\n\n<li>Deleting the unnecessary solid parts from the model<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Both of these operations can be performed within the <a href=\"https:\/\/www.simscale.com\/docs\/cad-preparation\/cad-mode\/\">CAD Edit<\/a> environment, which can be accessed from the <em>Geometries<\/em> tab:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1184\" height=\"776\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit.png\" alt=\"wind turbine - accessing cad edit in simscale\" class=\"wp-image-108098\" style=\"width:575px\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit.png 1184w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit-300x197.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit-1024x671.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-onshape-CAD-Edit-768x503.png 768w\" sizes=\"auto, (max-width: 1184px) 100vw, 1184px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 23: To access the CAD Edit, click on the highlighted icon from the image<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Initially, we are first interested in creating an external virtual wind tunnel. The image below shows the steps:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1645\" height=\"634\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape.png\" alt=\"wind turbine from onshape - external flow region\" class=\"wp-image-108100\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape.png 1645w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape-300x116.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape-1024x395.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape-768x296.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-external-flow-region-from-onshape-1536x592.png 1536w\" sizes=\"auto, (max-width: 1645px) 100vw, 1645px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 24: Creating an external wind tunnel within the CAD Edit environment<\/figcaption><\/figure>\n<\/div>\n\n\n<ol class=\"wp-block-list\">\n<li>Select an <strong>&#8216;External&#8217;<\/strong> flow volume operation, which will construct an enclosure<\/li>\n\n\n\n<li>Define the enclosure dimensions according to your geometry and wind direction<\/li>\n\n\n\n<li>Exclude the <em>Rotating zone<\/em> volume that was created in your CAD tool from the operation. This will ensure that the rotating zone is correctly constructed for the simulation<\/li>\n\n\n\n<li>Hit <strong>&#8216;Apply&#8217;<\/strong> to run the operation<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">At this point, the geometry is almost ready to run a simulation. To avoid <a href=\"https:\/\/www.simscale.com\/knowledge-base\/multiple-bodies-in-non-cht-simulation\">multi-region mesh errors<\/a>, it&#8217;s necessary to delete the solid parts from the geometry. In CAD Edit, we can proceed as follows:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape.png\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"406\" src=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape-1024x406.png\" alt=\"wind turbine from onshape - deleting parts rotating zone cad preparation\" class=\"wp-image-108101\" srcset=\"https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape-1024x406.png 1024w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape-300x119.png 300w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape-768x304.png 768w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape-1536x608.png 1536w, https:\/\/frontend-assets.simscale.com\/media\/2025\/10\/wind-turbine-delete-bodies-from-onshape.png 1666w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><figcaption class=\"wp-element-caption\">Figure 25: All solid parts should be deleted from the geometry. The only parts that should remain are the flow region and the rotating zone.<\/figcaption><\/figure>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Pick the <strong>&#8216;Delete&#8217; <\/strong>operation under <em>BODY<\/em><\/li>\n\n\n\n<li>Select the rotor blades, the nacelle, and the tower. Note that two volumes remain unselected: the flow region and the rotating zone<\/li>\n\n\n\n<li>Hit <strong>&#8216;Apply&#8217;<\/strong><\/li>\n\n\n\n<li>Click <strong>&#8216;Save&#8217;<\/strong> to export the new CAD version to your Workbench<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Now that we have only the two necessary volumes to run simulations with rotating zones, we can proceed to creating a simulation.<\/p>\n\n\n\n<div class=\"hw-block hw-note hw-note--info hw-note\">\n    <div class=\"hw-note__title\">\n        <p class=\"hw-note__titleText\"><i class=\"fa fa-exclamation-circle\" aria-hidden=\"true\"><\/i>Note<\/p>\n    <\/div>\n    <div class=\"hw-note__body\">\n        <p>If none of the above suggestions solved your problem, then please post the issue on our <a href=\"https:\/\/www.simscale.com\/forum\/\">forum<\/a> or <a href=\"mailto:support@simscale.com\">contact us<\/a>.<\/p>\n    <\/div>\n<\/div>\n<\/div><div id=\"eckb-article-content-footer\" ><div class=\"eckb-tag-container\"  ><span class=\"eckb-tag-description\">Tags:  <\/span><ul class=\"eckb-tag-list\"><li><a href=\"https:\/\/www.simscale.com\/knowledge-base\/tag\/ami\/\" rel=\"tag\">AMI<\/a><\/li><li><a href=\"https:\/\/www.simscale.com\/knowledge-base\/tag\/cad\/\" rel=\"tag\">CAD<\/a><\/li><li><a href=\"https:\/\/www.simscale.com\/knowledge-base\/tag\/cfd\/\" rel=\"tag\">CFD<\/a><\/li><li><a href=\"https:\/\/www.simscale.com\/knowledge-base\/tag\/mrf\/\" rel=\"tag\">MRF<\/a><\/li><li><a href=\"https:\/\/www.simscale.com\/knowledge-base\/tag\/rotating-zones\/\" rel=\"tag\">Rotating Zones<\/a><\/li><\/ul><\/div><\/div>\n\t\t        <\/article><!-- \/#eckb-article-content -->     <div id=\"eckb-article-right-sidebar\" ><\/div>\n\t\t\t<\/div><!-- \/#eckb-article-body -->              <div id=\"eckb-article-footer\" ><\/div>\n\t\t<\/div><!-- \/#eckb-article-page-container-v2 -->\n\n\t\t<style id=\"eckb-article-styles\" type=\"text\/css\">@media only screen and (min-width:768px){#eckb-article-page-container-v2 #eckb-article-body #eckb-article-content #eckb-article-content-header-v2 #eckb-article-content-header-row-1,#eckb-article-page-container-v2 #eckb-article-body #eckb-article-content #eckb-article-content-header-v2 #eckb-article-content-header-row-2,#eckb-article-page-container-v2 #eckb-article-body #eckb-article-content #eckb-article-content-header-v2 #eckb-article-content-header-row-3,#eckb-article-page-container-v2 #eckb-article-body #eckb-article-content #eckb-article-content-header-v2 #eckb-article-content-header-row-4,#eckb-article-page-container-v2 #eckb-article-body #eckb-article-content #eckb-article-content-header-v2 #eckb-article-content-header-row-5{flex-direction:row;}}#eckb-article-content-header-row-3{margin-bottom:32px;}#eckb-article-content-header-row-3 .eckb-article-content-header-row-left-group,#eckb-article-content-header-row-3 .eckb-article-content-header-row-right-group{align-items:flex-end;}<\/style>   ","protected":false},"excerpt":{"rendered":"<p>Skip to main content Created OnMarch 11, 2020 byTheresa When performing a simulation with rotating parts, such as pumps...","protected":false},"author":108,"featured_media":25017,"comment_status":"open","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_crdt_document":"","inline_featured_image":false,"footnotes":""},"epkb_post_type_1_category":[1773],"epkb_post_type_1_tag":[1823,1728,1744,1822,1821],"class_list":["post-24770","epkb_post_type_1","type-epkb_post_type_1","status-publish","has-post-thumbnail","hentry","epkb_post_type_1_category-cad-preparation","epkb_post_type_1_tag-ami","epkb_post_type_1_tag-cad","epkb_post_type_1_tag-cfd","epkb_post_type_1_tag-mrf","epkb_post_type_1_tag-rotating-zones"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/epkb_post_type_1\/24770","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/epkb_post_type_1"}],"about":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/types\/epkb_post_type_1"}],"author":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/users\/108"}],"replies":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/comments?post=24770"}],"version-history":[{"count":0,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/epkb_post_type_1\/24770\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/media\/25017"}],"wp:attachment":[{"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/media?parent=24770"}],"wp:term":[{"taxonomy":"epkb_post_type_1_category","embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/epkb_post_type_1_category?post=24770"},{"taxonomy":"epkb_post_type_1_tag","embeddable":true,"href":"https:\/\/www.simscale.com\/wp-json\/wp\/v2\/epkb_post_type_1_tag?post=24770"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}