1. PhD Thesis, Technical University of Catalonia, 2008. To achieve that theoretical minimum will depend on the selected design variables and the ability of the optimizer to identify a global minimum. The second value is the scale of the variable (typically left as 1.0). Suction side displacement thickness, in meters. In particular, we control the higher-order dissipation (added everywhere in the solution) by modifying the 2nd entry in the ADJ_JST_SENSOR_COEFF option. 3D design variables based on the free-form deformation approach (FFD) will be discussed in the next tutorial. If you are having trouble converging your adjoint calculation, we often recommend adjusting the level of dissipation, along with reducing the CFL condition with the CFL_REDUCTION_ADJFLOW option, or even imposing a hard limit on the value of the adjoint density variable using the LIMIT_ADJFLOW option. For this tutorial, we will use the NACA 0012 and the unstructured mesh from the Quick Start as our inputs with drag as our chosen objective and a set of Hicks-Henne bump functions to parameterize the shape. surface_adjoint.csv - comma separated values (.csv) file containing values along the airfoil surface. The continuous adjoint implementation in SU2 enables one to leverage many of the numerical methods found in the flow solver (often called the ‘primal’ or ‘direct’ solution). Neural Networks for Variational Problems in Engineering. 2. By launching the shape_optimization.py script (described below), a gradient-based optimizer will orchestrate the design cycle consisting of the flow solver, adjoint solver, and geometry/mesh deformation tools available in SU2. Figure (5): Pressure contours around the final airfoil design. restart_adj_cd.dat - restart file in an internal format for restarting this simulation in SU2. The initial geometry chosen for the tutorial is the NACA 0012 airfoil in transonic, inviscid flow. Log in sign up. The first value in the parentheses is the variable type, which is 1 for a Hicks-Henne bump function. User account menu. 5. The continuous adjoint methodology for obtaining surface sensitivities is implemented for several equation sets within SU2. The mesh consists of a far-field boundary and an Euler wall (flow tangency) along the airfoil surface. This example uses a 2D airfoil geometry (initially the NACA 0012) in transonic inviscid flow. The file airfoil_self_noise.csv contains the data for this example. Angle of attack, in degrees. Figure (2): Far-field and zoom view of the initial computational mesh. The SLSQP optimizer from the SciPy package for Python is the default optimizer called by the shape_optimization.py script. By using our Services or clicking I agree, you agree to our use of cookies. For this tutorial, we return to the classic NACA 0012 test case that was the subject of the Quick Start and perform aerodynamic shape design. "-//W3C//DTD HTML 4.01 Transitional//EN\">, Airfoil Self-Noise Data Set To run this design case, follow these steps at a terminal command line: Move to the directory containing the config file (inv_NACA0012_basic.cfg and the mesh file (mesh_NACA0012_inv.su2). C, Shape Design With Multiple Objectives and Penalty Functions, design/Inviscid_2D_Unconstrained_NACA0012. Many useful output files will be available to you at the conclusion. In other words, we would like to eliminate the shocks along the airfoil surface. Do any of you guys know where I can get the .csv file for this profile? However, note that the optimizer will often make multiple function calls per major optimizer iteration in order to compute the next step size. The python script will drive the optimization process by executing flow solutions, adjoint solutions, gradient projection, and mesh deformation in order to drive the design toward an optimum. It may also be helpful to review the Quick Start tutorial to refamiliarize yourself with this problem. After solving the direct flow problem, the adjoint problem is also solved which offers an efficient approach for calculating the gradient of an objective function with respect to a large set of design variables. Upon completing this tutorial, the user will be familiar with performing an optimal shape design of a 2D geometry. You will need the mesh file mesh_NACA0012_inv.su2 and the config file inv_NACA0012_basic.cfg. Then you can add the Z column and you'll be able to import the .csv file into STAR CCM+.”, Thanks for the reply. Any pregnancy success stories after HSG? K. Lau. The design loop is driven by the shape_optimization.py script, and thus Python along with the NumPy and SciPy Python modules are required for this tutorial. Frequency, in Hertzs. The airfoils below are *.dat ou *.cor. T.F. Upon completing this tutorial, the user will be familiar with performing an optimal shape design of a 2D geometry. AoA, Constrained shape design of a transonic turbulent airfoil at a cte. During the optimization process, the SLSQP optimizer will call the flow and adjoint problems as necessary to take the next step in the design space. Computer Program to Obtain Ordinates for NACA Airfoils Computer programs to produce the ordinates for airfoils of any thickness, thickness distribution, or camber in the NACA airfoil series were developed in the early 1970's and are published as NASA TM X-3069 and TM X-3284. The general process for performing gradient-based shape optimization with SU2 is given in the flow chart at the top of the page. As a side note, in case you are planning to use the discrete adjoint mode, SU2 software will not use these parameters unless you activate the option INCONSISTENT_AD. For the airfoil problem, we want to minimize the drag by changing the surface profile shape. Donor: Dr Roberto Lopez robertolopez '@' intelnics.com Intelnics Creators: Thomas F. Brooks, D. Stuart Pope and Michael A. Marcolini NASA. Figure (4): Adjoint density contours on the baseline NACA 0012 airfoil.