The Concept
\n", "[Razlib.ru [4]](http://www.razlib.ru/transport_i_aviacija/ayerohobbi_1992_02/p3.php)\n", "\n", "This website appears to be a paper published that has some very interesting background information on it. If one is curious to learn more, follow the link and use Google to translate that page into english. Thats what I did since my Russian is non-existant!" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "
" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "So now that we have our drawings, what's the next step to digitizing? Using a free opensource 3d modeling program of course! My alltime favorite, and one I've used for years is [Blender3D](https://www.blender.org/).\n", "\n", "Not going into super details about the process, but what I did in a nutshell was:\n", "* Import the drawings\n", "* Created both the airfoils and the body shape in Blender3D using Bezier curves\n", "* Converted the curves to a mesh\n", "* Wrote a custom Python script which exports the vertices\n", "* Correctly import the proper way XFLR5 requires\n", "\n", "These steps have taken the longest. Days and days have been spent figuring this part out, as XFLR5 is a bit temperamental with how it wants the correct inputs. Some images below show the steps I took." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Fitting the Curves!\n", "\n", "
\n", "Curve the Airfoil. Make sure you do Trailing edge over the top to the Leading edge, then back around again.\n", "
\n", "Beginning the 2D cross section production.\n", "\n", "The Meshes!\n", "\n", "
\n", "The Mesh 2D cross sections\n", "
\n", "The Mesh 2D cross sections into the plane shape which is our 3D model.\n", "\n", "Finally, XFLR5 models!\n", "\n", "
\n", "The final airfoil shape in XFLR5.\n", "
\n", "The completed craft, airfoils, body, elevators and fins. Beautiful..." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "One might notice that the imported XFLR5 model of the body is alittle bit different than the image above of the blender file with all those vertex points. The reason being is that I had to make a simplified version due to XFLR5 crashing! Here's an image of the high resolution model before it would shut down every single time...." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "
" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "A word of warning to those wishing to follow my steps.... don't make your mesh too big! It will load, then stutter, then crash.... wings too! So don't put too many panels on your wings and body else you won't get very far." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "
" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "
Wing Studies
" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "As I mentioned in the previous section, this entire case study has taken place in [XFLR5](http://www.xflr5.com/xflr5.htm). A free program which allows enthusiasts and hobbyists to analyze model planes, airfoils, and anyone who feels like playing around with an amazing program.\n", "\n", "With the blendering all done and model files exported and imported, it's time to have some fun and run some simulations! A few errors occured when I tried to make this foil the actual size of the aircraft though, and I gave up on trying to simulate the full scale model. XFLR5 just can't handle the computations (or perhaps my computer can't) as I believe this was designed for model aircrafts (well, it's primarily being used for them currently anyways). Therefore, throughout all these simulations, I have run a smaller version of the craft (about 10 times smaller) created from the diagrams above. The initial runs were very preliminary to get a feeling and understanding of the program, and to the best of my abilities, I have used XFLR5 to get some results. Also, a short note is that the type of simulations run on both the wings and the body were [Horshoe Vortex (VLM1)](http://en.wikipedia.org/wiki/Horseshoe_vortex) analyses with viscous effects. \n", "\n", "Shown below is an animation after running the batch analysis and the initial trial runs:" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "