Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a...
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Transcript of Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a...
![Page 1: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/1.jpg)
Low Speed Airfoil Design
Joan Puig
![Page 2: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/2.jpg)
Project Goals
● Maximize L/D● Easy to build● Keep Cm at a value that is not going to make the
airplane unstable● Have space for a strong structure● Design an optimal airfoil for my RC airplane
![Page 3: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/3.jpg)
Tools
● Panel Method to generate Cp distribution● Shape adjusting function● Optimizer● Drag estimation tools (future work...)
![Page 4: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/4.jpg)
Shape Adjusting Function
● It generates any reasonable airfoil starting from a guess and a set of linerly independent bump functions.
![Page 5: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/5.jpg)
Bad bump function choice
![Page 6: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/6.jpg)
Optimization Process Review
● Don't assume anything about the input data● Fit the input data using a spline to the desired X
coordinate values● Pass appropriate parameters to the optimization
function● Collect data periodically
![Page 7: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/7.jpg)
Guess
![Page 8: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/8.jpg)
20 Iterations
![Page 9: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/9.jpg)
40 Iterations
![Page 10: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/10.jpg)
60 Iterations
![Page 11: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/11.jpg)
Final Result
![Page 12: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/12.jpg)
Convergence rate
![Page 13: Low Speed Airfoil Design Joan Puig Project Goals ● Maximize L/D ● Easy to build ● Keep Cm at a value that is not going to make the airplane unstable.](https://reader035.fdocuments.in/reader035/viewer/2022062719/56649ee75503460f94bf7fee/html5/thumbnails/13.jpg)
Speed
● Solving a matrix is o(n^3) -> most of the time is spent here
● Try to be able to fit your matrix in the cache– 32*(n^2+8n)/(8*1024)<available cache ~128-512
● Don't calculate x^2, x^3, sin(...) exp(...^n)... every time, compute them at the beginning and use them as global variables