New Capability Efforts:

1) Adding a discrete adjoint blade shape design optimization capability to the harmonic balance (HB) version of TURBO.  This would be a research effort at first, primarily to see if it is feasible with the HB/TURBO source code, and if it is doable, we could then develop a computational tool that would enable the design of turbo-machinery blades optimized to maximize unsteady aerodynamic damping.

2) Adding a multistage capability to the harmonic balance version of TURBO.  This would enable the flow analysis of multiple blade rows, while only requiring the computational modeling of a single blade passage per row.

 Technical Enhancement Efforts:

1) Incorporate the AEPREP mode shape unsteady grid file generator code within the HB version of TURBO code.  This would then eliminate the need to generate new unsteady grid files for every inter-blade phase angle under consideration in a given flutter analysis when running HB/TURBO.

2) Improve computational load balancing for parallel computations.  The latest version of TURBO is set up so that individual computational blocks can be broken up into sub-blocks.   Currently, the computational block with the largest number of grid points governs the overall speed of computations when running a parallel multi-block grid configuration model.  Splitting up the larger grid blocks into sub-blocks, and then sending the computations for each sub-block off to an individual processor, could speed up computations dramatically.  Code will need to be developed that can do the splitting of the main grid blocks into sub-blocks automatically, and parallel code will need to be written to handle the computations for each of the grid sub-blocks.

3) Current version of 2D interpolation interface is only for one interface. Modify TURBO to allow for multiple 2D interpolation interfaces.

4) Development of 2D non-reflecting boundary conditions.

5) Apply current inlet-fan simulation capability to new geometry of NASA interest.

6) Structural response of the current inlet-fan case to show blade stall.

7) Convert TURBO code for GPU-based clusters to reduce run time.

8) A software development framework so that new models and updates can be easily integrated by users to their own versions of TURBO.

9) Develop a new pre-processor similar to GUMBO for TURBO based on Pointwise grids.

10) A blade design optimization code integrated with the TURBO for distortion-tolerant fan blade design to mitigate flow distortion. The optimization capability can be modified to address other flow-related design optimization problems.

11) Flow analysis pertaining to nonsynchronous blade vibration and stall through mode decomposition methods. Using mode decomposition as an analysis tool to compare the underlying flow phenomena between rotating stall and nonsynchronous vibration in subsonic and transonic rotors would provide new insights into the flow mechanisms allowing for alleviation in the future. These insights are unveiled through mode decomposition information regarding boundary layer stability, free stream/blade passage structures, and pressure variations which all contribute to stall and vibration.

12) Mode decompositions rely on a modal-like analysis in which temporal and structural information is described in orthogonal modes. This feature can be utilized to significantly reduce the data size of unsteady CFD simulations.

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