# Step-by-Step Tutorial: Homework of Session 1 - Level 2 **URL:** \ **Category:** Drone Workshop (2015)\ **Created:** [October 15, 2015, 1:44pm UTC](https://www.simscale.com/forum/t/step-by-step-tutorial-homework-of-session-1-level-2/310 "2015-10-15T13:44:25Z")\ **Posts on this page:** 1\ **Showing post:** 1
**Author:** ![anon67859130](https://www.simscale.com/forum/letter_avatar/anon67859130/32/6_22734026db12803ebb3e059622ac3534.png) [@anon67859130](https://www.simscale.com/forum/u/anon67859130)\ **Post date:** [October 15, 2015, 1:44pm UTC](https://www.simscale.com/forum/t/step-by-step-tutorial-homework-of-session-1-level-2/310/1 "2015-10-15T13:44:26Z")
> NOTE: This tutorial was updated on 08/2016 to match the updated version of the platform If you would like to watch the first session of the Drone Workshop again or in the case you missed it, you can access the full recording below. [![](https://www.simscale.com/forum/uploads/default/original/3X/c/a/ca92f43418a517ca232c7533bc7587a05b942cb0.jpeg "Drone Workshop (Session 1) - Aerodynamics of a Single Rotating Propeller") ](https://www.youtube.com/watch?v=NhXq69ZRvoM) You have just set up your [first simulation of the aerodynamics of a drone](https://www.simscale.com/forum/t/step-by-step-tutorial-homework-of-session-1-level-1/297) from the first session of our online Drone Workshop.Now we will start Level 2. # Level 2 ## Background: Level 2 includes the CFD analysis of the modified ducted-fan geometry for the drone. This task requires you to firstly generate the mesh with a rotating zone and then setup a simulation with Multi-Reference-Frame (MRF) and advanced boundary conditions. ## Step-by-Step instruction ## Mesh The CAD geometry is already provided in the **Drone\_HW-task-2** project, [that can be imported here] - Under the geometry tree, click on the geometry **Drone\_Ducted-Fan-STEP**. From the geometry options panel, click on **Mesh geometry**. This will automatically create a Mesh operation and make the mesh operation selection panel active. - From the panel select \> **Hex-dominant parametric (only CDF)**. This type of meshing approach is necessary for the generation of a ‘rotating zone’ that is required for the analysis. **Important: The rotating zone is defined using an additional solid region included in the CAD geometry.** - In the same panel under **Bounding Box Discretization** specify the following values for number of cells in each X,Y and Z directions for the **BaseMeshBox** as shown in figure below: ![](https://www.simscale.com/forum/uploads/default/original/2X/2/203761f4265ca75a85ad6c9586a25c7e162ac58f.png) - Number of cells in x direction: 40 - Number of cells in y direction :65 - Number of cells in z direction : 40 - and under ‘Parallel Processing’, the number of processors as : 32. At the top, click on _Save_. After saving , sub-trees named _Geometry Primitives_ and _Mesh Refinements_ will automatically appear under the default ‘Operation 1’ tree. Under _Geometry Primitives_, click on _BaseMeshBox_ and specify the values as shown below and click on ‘save’ ![](https://www.simscale.com/forum/uploads/default/original/2X/d/d1fa49ba0d49d79b5ceef0ac24275c2ba3673919.png) Next, click on _material point_ and specify the following sample values: Center (x) : 0.113 Center (y) : 0.0677 Center (z) : 0.1731 This will place the material point in the space between the Bounding BaseMeshBox and the geometry surfaces. So, this is the confined space that will be meshed. Next, create 3 additional geometry primitives by clicking on _Geometry Primitives_ and then New from the options panel and select type _cylinder_. These will be used to define _Region Refinements_ later on. - Name the first as _Cylinder-outer_ and specify the values shown in figure below and click ‘save’: ![](https://www.simscale.com/forum/uploads/default/original/2X/e/e2c0367bd8e1b3b8715f4c39b6a30f899f938976.png) Similarly, for the other 2 geometry primitives of type _cylinder_ specify the values given below: ![](https://www.simscale.com/forum/uploads/default/original/1X/ea70b92182a8c196b44a57047d174a1dcb60dede.png) Make sure you ‘save’ after each one. Now, we will group the geometry solids under the _Topological Entity Sets_ tree. First click on the _pick volumes_ icon in in the tool bar above visualization window. Then select the MRF-zone and click on “Create entity set from viewer selection” in the options panel. Onces created, hide the volume by selecting it again and clicking _hide selection_ from the tool bar (slashed eye icon) so that only the rest of the volumes are visible. ![](https://www.simscale.com/forum/uploads/default/original/2X/c/ce9d54c4eb1480e714bc6a261ca814f0c2ccbbc4.png) Do the same for the 3 other volume sets. Once all volume sets are created, click on the _show all_ icon in the tool bar (right to the hide selection icon). Duct: Solid\_0 Arm-assembly: Solid\_1 MRF-Zone: Solid\_2 Blade-1: Solid\_3 Blade-2: Solid\_4 Next, from the visualization window selection tree, we will hide the Solid\_0 till Solid\_2 , by clicking off the eye symbols. Then, on the tool bar we click on icon _pick faces_, then click on selection and select all. This will select all visible faces of the rotor-blade. Lastly, click on Create entity set from viewer selection and name it _blade-faces_ ![](https://www.simscale.com/forum/uploads/default/original/2X/e/e8ecd6a6414304ce7a0cc9f0ef4654429613c6c2.png) Now, we add the necessary surface, region and layer refinements for the mesh. Click on _Mesh refinements_ in the tree and _add new mesh refinement_ from the options panel. Then select and enter the values as shown in the figure below. Care must be taken that here for the type _surface refinement_ , the _create cell zone_ must be set to _True_ and the volume set _MRF-Zone_ must be assigned. ![](https://www.simscale.com/forum/uploads/default/original/2X/b/b3f6dae69ea9a22bf16eb41eb7ca0a9e25296a93.png) For refinement of the surface mesh of _Arm-assembly_ and _duct_ we add a new surface refinement and assign the values as shown in figure below: ![](https://www.simscale.com/forum/uploads/default/original/2X/3/3421a4e41b35636a9822037bfe121e1276c28177.png) For refinement of blade surface mesh , we add another surface refinement as follows: ![](https://www.simscale.com/forum/uploads/default/original/2X/c/c94f0bdd2a6d611fb3ee0a152367e13330adf61f.png) For refinement of the volume mesh region we add 3 region refinements of different refinement levels. So, click add refinements and add a region refinement as depicted below and save it. ![](https://www.simscale.com/forum/uploads/default/original/2X/d/d30bedb91a6e999ac0e57495d2f17a8555495820.png) Add 2 more region refinements with the specified values and save after each: ![](https://www.simscale.com/forum/uploads/default/original/1X/b9e0f74dc8873ad257e824b1b92ac87a5a400920.png) Lastly, we add body aligned cell layer to the rotor blade faces. So, create a new mesh refinement and select Layer addition with following values. ![](https://www.simscale.com/forum/uploads/default/original/2X/1/1450b6099c8f1aaba7df3616a2dd433f51a6f425.png) All the mesh refinements are now complete. We will now adjust some additional (advanced) settings to get a better quality mesh. So, make sure the corresponding values are as shown in the figures below: ![drone workshop, drone design, mesh refinement](https://www.simscale.com/forum/uploads/default/original/2X/b/bf694295996312a453dfa46487e4fc213cbdb2c4.png "Make sure the corresponding values are as shown in the figure") ![](https://www.simscale.com/forum/uploads/default/original/2X/6/607866b94f3f417c51a6ec5885064fba26e59b40.png) Once done, click save and start the meshing process by clicking on the start button at top. The meshing process will take less than an hour to finish. ## Simulation Setup Switch to the _Simulation Designer_ tab and select _New Simulation_. Enter preferred name and click _create_. From analysis Type select the options as shown in the figure below and click ‘save’. After saving, a tree will automatically generate in the left panel window that will be completed step by step. ![](https://www.simscale.com/forum/uploads/default/original/2X/3/3f271a813b8682b6e411291e16645b2060f0cc2c.png) Next from the tree, click on _Domain_ and select the mesh under _Meshes_ and click _Save_ as shown in figure below. After saving, the mesh will automatically load in the visualization window. ![](https://www.simscale.com/forum/uploads/default/original/2X/c/c090ec2f05728cc73a1da0a1cfe8e56a175dbf68.png) Now, we will create face sets under _Topological Entity Sets_ that will be used to define boundary conditions later on. Click on _pick faces_ icon in tool bar [2] and select the highlighted faces [3] as shown in figure below. Change filter for entity types to _face sets_ [4] and click on _Create entity sets from viewer selection_ [5] to create the _Symmetry-faces_ set. ![](https://www.simscale.com/forum/uploads/default/original/2X/1/1da3a2ec9fcd4cd8ca91c358d2461011e8a04302.png) Before creating the next set, we will hide the previous set _Symmetry-faces_ by clicking on it [3] and clicking _hide selection_ icon [4] to hide it. Now, we select _pick faces_ from tool bar [5] and select the highlighted _side faces_ as shown in figure below [6] and click on _Create entity sets from viewer selection_ [7] to create the sets called _Side-faces_. ![](https://www.simscale.com/forum/uploads/default/original/2X/8/8ff72d07aa5c6752197e923a6165120990334e14.png) Similarly, we follow the above steps to one by one create 2 new sets called _Top-face_ and _Bottom-face_ by selecting the corresponding faces shown in above figure. Onces done, we one-by-one hide the four face sets as shown in figure below [2] . Next, we select _pick faces_ from tool bar [3] and select the highlighted _Duct faces_ as shown [4] to create another set. ![](https://www.simscale.com/forum/uploads/default/original/2X/6/66c746ade6c8754ef882f81c9f1c18986feabf52.png) Again, we hide set _Duct-faces_ first and then select all rotor faces (30 in total) to create a set called _Rotor-Blade_ as shown below. ![](https://www.simscale.com/forum/uploads/default/original/2X/1/19bf6fe50d1a1cd5cb8fcdf471e5ee434c9a6610.png) lastly, hide all created sets [2] and click _pick faces_ from tool bar [3]. Now we see only the Arm-assembly in the viewer as shown in figure below. Click on _selection_ in tool bar and _Select all_ [4] to select all visible faces at once. So, create the last set called _Arm-assembly-faces_ by clicking on create set button [5]. ![](https://www.simscale.com/forum/uploads/default/original/2X/3/3b6895199635b90a3d9f41d1298bf99398aac37b.png) Adding Materials ![](https://www.simscale.com/forum/uploads/default/original/2X/4/4708588e767db74c5e997dbbdba4788ef5d637b8.png) ![drone workshop, drone design, add materials](https://www.simscale.com/forum/uploads/default/original/2X/a/a5673bf3d658d68f4424dd62abeba481c11e065d.png "Import from material library") ![](https://www.simscale.com/forum/uploads/default/original/2X/6/65317ef1eda6f71a7531e7e52f33db79885d6038.png) ![](https://www.simscale.com/forum/uploads/default/original/2X/3/3ca1f8b0444de492f49c940dc66d410389e022bd.png) Now, we define the boundary conditions by clicking on the sub-tree named _Boundary Conditions_ and clicking _New_ from the options panel. ![](https://www.simscale.com/forum/uploads/default/original/2X/d/de425102942d6c15a7ba42e0cc60e0fa43a3e28c.png) To define no-slip wall condition for the drone, enter and select the options as shown in figure below . Please note that you do NOT need to select from the viewer. Just assign by clicking the shown face set and click _Save_. ![](https://www.simscale.com/forum/uploads/default/original/2X/5/55fa7a7daa977446c12ec8ea77ffa8bf96527fd4.png) The second boundary condition is type symmetry and is setup as shown below. Again, just assign by clicking the shown face set and click _Save_ (no selection from viewer required) ![](https://www.simscale.com/forum/uploads/default/original/2X/a/a416eada024253c6411db09395295cac1b2e39a3.png) Similarly, we create a new Slip-wall condition for the _Side/Bottom Faces_ as illustrated in figure below. ![diy drone design simulation setup, slipwall boundary condition](https://www.simscale.com/forum/uploads/default/original/2X/3/38a84b4bd1cf9252d76181d8a8cc11c38a08ac5a.png "New Slip-wall condition for the Side/Bottom Faces") Lastly, we will make the top face an _open boundary_ face that can act as a free flow inlet or outlet (at the same time) depending upon the flow inside the domain. To do third we choose type as _Custom_ and set the values as shown in figure below: ![](https://www.simscale.com/forum/uploads/default/original/2X/6/6cab0e9e3c0f52b2d5ae64580bb831ac288152b1.png) Now to define the rotation zone, click on _Advanced Concepts_ sub-tree entry and _Add rotating zone_ by clicking on the button in options panel as shown below. ![](https://www.simscale.com/forum/uploads/default/original/2X/6/62cafca64262b4ad3d2153e90b17bc9192d2ee44.png) Select and assign the values as shown in the figure below to set the rotating MRF zone. Check _RotatingZone_ under _MRF Zone_ section for entity types _volumes_ and click _save_ ![](https://www.simscale.com/forum/uploads/default/original/2X/c/ca8aab91388536346d140597436620de7846919e.png) Under the _Numerics_ sub-tree entry make the changes as shown in the figures below and save them. ![](https://www.simscale.com/forum/uploads/default/original/2X/2/2e6e1a0d7d42f5924b8f1551ce1e9cc0d1e9cfe9.png) ![](https://www.simscale.com/forum/uploads/default/original/2X/f/f2ed80a9e281118e788f2b6ba2362cb4b9769193.png) Make the following changes to the values as shown in figure below. ![](https://www.simscale.com/forum/uploads/default/original/2X/7/74f7b1faeff26b33b3c3ebe4f94c0cd3b3bca991.png) Click on _Result Control_ and click _New_ and add _Forces and Moments_ item from the options panel and enter the values as shown in figures below. (Again, No selection from viewer is required). ![](https://www.simscale.com/forum/uploads/default/original/2X/8/89d9c51e36957de971689a66cb97defa73cf1010.png) ![](https://www.simscale.com/forum/uploads/default/original/2X/0/0d2f3047f6146baf7508b44d7253b291d28ec457.png) Finally, click on _Simulation Runs_, then on _Create new run_ from the options panel as shown and start the run. Thats all … ! ![](https://www.simscale.com/forum/uploads/default/original/2X/2/2ca2d0cab0225eed5e315d3ea06ee2cf97b7a6af.png) Congratulations, you have completed the Homework of Session 1 - Level 2 and can now move on to Session 2: ### [Homework of Session 2 - Level 1](https://www.simscale.com/forum/t/step-by-step-tutorial-homework-of-session-2-level-1/387) --- _[View the full topic](https://www.simscale.com/forum/t/step-by-step-tutorial-homework-of-session-1-level-2/310)._