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- - **Inaccurate gradient results from continuous Adjoint method**
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Inaccurate gradient results from continuous Adjoint methodDear all,
I'm studying global optimization methods. Currently, I consider airfoil design as the application. However, I have found inaccurate gradient results when I use the continuous Adjoint method which is enclosed in the SU2-Suite. Here is the information of the airfoil design. Airfoil: RAE2822 Mach number = 0.75 AoA= 1.25deg Design variables= 5 Hicks-Henne bump functions on the upper surface of the airfoil In order to measure the accuracy of the Adjoint method, I considered 2 bump functions, and compared gradient values from the Adjoint method and finite difference method. All computation conditions(grid, # of CPUs, etc) were same except the method. http://amdl.kaist.ac.kr/wp-content/u...12/export2.jpg The above is the two plots. White and red plots were each calculated using the finite difference and the Adjoint method. As you can see, the overall trends and the magnitudes of the plots are different each other. Since step size for the finite difference method was selected by some tests, I think the finite difference method is accurate. What makes the difference? Is this a limitation of the Adjoint method? |

If you have a while, please take a look at
https://adl.stanford.edu/papers/AIAA-2013-1042.pdf Best Regards, Francisco |

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