Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane
High fidelity simulations, e.g., large eddy simulation are often needed for accurately predicting pressure losses due to wake mixing and boundary layer development in turbomachinery applications. An unsteady adjoint of high fidelity simulations is useful for design optimization in such aerodynamic a...
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| Format: | Article |
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ASME International
2018
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| Online Access: | http://hdl.handle.net/1721.1/116206 https://orcid.org/0000-0002-3211-6003 https://orcid.org/0000-0001-9669-2563 |
| _version_ | 1826199442965921792 |
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| author | Laskowski, Gregory M. Talnikar, Chaitanya Anil Wang, Qiqi |
| author2 | Massachusetts Institute of Technology. Department of Aeronautics and Astronautics |
| author_facet | Massachusetts Institute of Technology. Department of Aeronautics and Astronautics Laskowski, Gregory M. Talnikar, Chaitanya Anil Wang, Qiqi |
| author_sort | Laskowski, Gregory M. |
| collection | MIT |
| description | High fidelity simulations, e.g., large eddy simulation are often needed for accurately predicting pressure losses due to wake mixing and boundary layer development in turbomachinery applications. An unsteady adjoint of high fidelity simulations is useful for design optimization in such aerodynamic applications. In this paper we present unsteady adjoint solutions using a large eddy simulation model for a vane from VKI using aerothermal objectives. The unsteady adjoint method is effective in capturing the gradient for a short time interval aerothermal objective, whereas the method provides diverging gradients for long timeaveraged thermal objectives. As the boundary layer on the suction side near the trailing edge of the vane is turbulent, it poses a challenge for the adjoint solver. The chaotic dynamics cause the adjoint solution to diverge exponentially from the trailing edge region when solved backwards in time. This results in the corruption of the sensitivities obtained from the adjoint solutions. An energy analysis of the unsteady compressible Navier-Stokes adjoint equations indicates that adding artificial viscosity to the adjoint equations can dissipate the adjoint energy while potentially maintain the accuracy of the adjoint sensitivities. Analyzing the growth term of the adjoint energy provides a metric for identifying the regions in the flow where the adjoint term is diverging. Results for the vane from simulations performed on the Titan supercomputer are demonstrated. |
| first_indexed | 2024-09-23T11:19:59Z |
| format | Article |
| id | mit-1721.1/116206 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T11:19:59Z |
| publishDate | 2018 |
| publisher | ASME International |
| record_format | dspace |
| spelling | mit-1721.1/1162062022-10-01T02:55:29Z Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane Laskowski, Gregory M. Talnikar, Chaitanya Anil Wang, Qiqi Massachusetts Institute of Technology. Department of Aeronautics and Astronautics Massachusetts Institute of Technology. Computation for Design and Optimization Program Talnikar, Chaitanya Anil Wang, Qiqi High fidelity simulations, e.g., large eddy simulation are often needed for accurately predicting pressure losses due to wake mixing and boundary layer development in turbomachinery applications. An unsteady adjoint of high fidelity simulations is useful for design optimization in such aerodynamic applications. In this paper we present unsteady adjoint solutions using a large eddy simulation model for a vane from VKI using aerothermal objectives. The unsteady adjoint method is effective in capturing the gradient for a short time interval aerothermal objective, whereas the method provides diverging gradients for long timeaveraged thermal objectives. As the boundary layer on the suction side near the trailing edge of the vane is turbulent, it poses a challenge for the adjoint solver. The chaotic dynamics cause the adjoint solution to diverge exponentially from the trailing edge region when solved backwards in time. This results in the corruption of the sensitivities obtained from the adjoint solutions. An energy analysis of the unsteady compressible Navier-Stokes adjoint equations indicates that adding artificial viscosity to the adjoint equations can dissipate the adjoint energy while potentially maintain the accuracy of the adjoint sensitivities. Analyzing the growth term of the adjoint energy provides a metric for identifying the regions in the flow where the adjoint term is diverging. Results for the vane from simulations performed on the Titan supercomputer are demonstrated. United States. Department of Energy. Office of Science (Contract DE-AC05-00OR22725) 2018-06-11T16:02:14Z 2018-06-11T16:02:14Z 2016-06 2018-04-12T17:23:15Z Article http://purl.org/eprint/type/ConferencePaper 978-0-7918-4978-1 http://hdl.handle.net/1721.1/116206 Talnikar, Chaitanya, Qiqi Wang, and Gregory M. Laskowski. “Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane.” Volume 5A: Heat Transfer (June 13, 2016). https://orcid.org/0000-0002-3211-6003 https://orcid.org/0000-0001-9669-2563 http://dx.doi.org/10.1115/GT2016-56689 Volume 5A: Heat Transfer Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf ASME International ASME |
| spellingShingle | Laskowski, Gregory M. Talnikar, Chaitanya Anil Wang, Qiqi Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title | Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title_full | Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title_fullStr | Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title_full_unstemmed | Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title_short | Unsteady Adjoint of Pressure Loss for a Fundamental Transonic Turbine Vane |
| title_sort | unsteady adjoint of pressure loss for a fundamental transonic turbine vane |
| url | http://hdl.handle.net/1721.1/116206 https://orcid.org/0000-0002-3211-6003 https://orcid.org/0000-0001-9669-2563 |
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