Development of a discrete adjoint-based aerodynamic shape optimization tool for natural laminar flows

Date

2020

Author

Kaya, Halil

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

322
views

0
downloads

An adjoint-based aerodynamic shape optimization framework for natural laminar flows is developed. A Reynolds-Averaged Navier-Stokes flow solver with the Spalart-Allmaras turbulence model is coupled with the recently developed Bas-Cakmakcioglu transition model in order to predict laminar to turbulent transition onset. In the gradient-based optimization process, the sensitivity derivatives required by the optimization algorithm is obtained by the discrete adjoint method, which is developed for the in-house flow solver and implemented for natural laminar flow airfoils and wings. In the development of the discrete adjoint method, an automatic differentiation tool is employed to take the discrete derivative of the modules in the in-house flow solver heavily modified. The parametrization of the aerodynamic surface is realized by the Free-Form Deformation technique. The sensitivity derivatives with respect to design parameters, which are computed by the adjoint method, are validated with the finite-difference method. The success of the adjoint-based aerodynamic shape optimization methodology developed in this study is then demonstrated by optimizing aerodynamic characteristics of several airfoils and wings for compressible turbulent and natural laminar flows.

Subject Keywords

Laminar flow., Discrete Adjoint Method Natural Laminar Flow Aerodynamic Shape Optimization Laminar to Turbulent Transition Model Computational Fluid Dynamics .

URI

http://etd.lib.metu.edu.tr/upload/12625618/index.pdf
https://hdl.handle.net/11511/45818

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Validation of depth-averaged mixing length turbulence model for uniform channel flows/ Karaman, Çağrı Hasan; Aydın, İsmail; Department of Civil Engineering (2014) A one-dimensional depth averaged turbulence model based on volumetric mixing length definition is developed for shallow flows. Numerical solution of the model is done using finite volume method for steady, uniform closed duct flows to observe lateral momentum exchange over depth discontinuities. The model is verified by comparison to two-dimensional numerical solutions and to the experimental data available in the literature. The model is then applied to uniform free surface flows in rectangular and compoun...
Numerical Simulation of Rarefied Laminar Flow past a Circular Cylinder Çelenligil, Mehmet Cevdet (2014-07-18) Numerical simulations have been obtained for two-dimensional laminar flows past a circular cylinder in the transitional regime. Computations are performed using the direct simulation Monte Carlo method for Knudsen numbers of 0.02 and 0.2 and Mach numbers of 0.102 and 0.4. For these conditions, Reynolds number ranges from 0.626 to 24.63 and the flows are steady. Results show that separation occurs in the wake region for the flow with Mach number of 0.4 and Knudsen number of 0.02, but for the other eases flow...
Aerodynamic shape optimization of a wing using 3d flow solutions with su2 and response surface methodology Yıldırım, Berkay Yasin; Tuncer, İsmail Hakkı; Department of Aerospace Engineering (2021-4) In this study, the aerodynamic shape optimization of a wing is performed by using 3D flow solutions together with response surface methodology. The purpose of this study is to optimize the aerodynamic shape of a wing to achieve the lowest possible drag coefficient while ensuring desired maneuvering capability and lateral stability. Aerodynamic shape optimization is performed for a wing of a turboprop trainer aircraft. Optimization objective and constraints are determined according to mission requirements an...
Simulation of laminar microchannel flows with realistic 3D surface roughness Akbaş, Batuhan; Sert, Cüneyt; Department of Mechanical Engineering (2019) Effects of flow development and surface roughness on the pressure drop characteristics of laminar liquid flowsinside microchannels are investigated numerically using OpenFOAM. Channels with square cross section of 500 μm×500 μmand length of 80 mm are studied. Top surface of the channels are artificially roughened using thespatial frequency methodto create 8 different roughness profiles. Scaling the relative roughness ({u1D700}) values of each profile to three different values (1.0, 2.5and5.0 %),a total of 2...
Design and analysis of a vertical axis water turbine for river applications using computational fluid dynamics Demircan, Eren; Aksel, Mehmet Haluk; Pınarcıoğlu, Mehmet Melih; Department of Mechanical Engineering (2014) The main purpose of this study is to design a Darrieus rotor type vertical axis water turbine using Computational Fluid Dynamics (CFD) in order to be used in river currents. The CFD modeling is based on two dimensional numerical solution of the rotor motion using commercial Unsteady Reynolds Averaged Navier-Stokes solvers, Ansys Fluent and CFX. To validate the two dimensional numerical solution, an experimental Darrieus rotor type water turbine from literature is studied and performance of several turbulenc...

Citation Formats

H. Kaya, “Development of a discrete adjoint-based aerodynamic shape optimization tool for natural laminar flows,” Thesis (Ph.D.) -- Graduate School of Natural and Applied Sciences. Aerospace Engineering., Middle East Technical University, 2020.