This exercise requires the learners to use Flow Illustrator to calculate the flow past a mirror, the shape of which they designed themselves, and to compare it to the flow past a blunt mirror. The goal of the comparison is to determine the relative reduction of the mirror drag.
First, download the picture of the bluff mirror in Fig.L7 from here (right-click on the picture and save).
Fig.L7 Image of an old mirror
The picture you will download will not have a frame around it. This is all right, here the frame is added for clarity. Then, using Paint or another similar program, modify the picture adding your own cowling for the mirror. A cowling is a streamlined enclosure for reducing the drag. For example, you can get a picture similar to Fig.L8:
Fig.L8 Modified image of the mirror
The colour does not matter: anything non-white will be considered as a solid body. Here it is used to show the cowling. However, keep the height of the mirror base the same as the height of the bluff mirror, to make the comparison valid. Save you picture as bmp file, that is in the same format as the original.
Go to Flow Illustrator Run Simulation page. Press the “Choose file” button, select you image file, and upload it. You will now see your file in the window on the web page. Change the “Video length in seconds” to 60. Do not change anything else (you can have a look around the website on your own, learning more). Type in the gotcha code to prove that you are not a robot and press “Submit”. If everything was done correctly, the next page will show you the code for your video. Copy it and save somewhere, as you may need it later. The video of this size takes about 4 minutes to be made. However, there might be a queue, and then you may have to wait longer. You can press the “Check now” button, and observe the progress of your video. Eventually, you will be shown a page with a download link. Click on it, and save your video to your computer. You can watch it now with the player of your choice.