Evaluation and Improvement of the PBD-X/MTFLOW Propulsor Analysis Software
Final rept. May-Sep 2009
NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
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The software suite PBD-XMTFLOW has been exercised for evaluation with both waterjet pumps and open propellers. PBD-X is a lifting surface propeller analysis code for steady conditions. MTFLOW is an axisymmetric Euler solver used to solve the axisymmetric component of the flow field inside of a waterjet pump or in and around a propeller. The results of the PBD-XMTFLOW calculations were compared with PBD-14MTFLOW calculations. PBD-14 is an earlier lifting surface code which uses a different formulation for determining the effective wake when coupled with MTFLOW. It was found that PBD-X produces almost identical results to PBD-14 for open propellers when coupled with MTFLOW. For waterjet pumps, PBD-X predicts significantly less circulation. The reason for this difference is not known. However, it may be related to the different formulation used in PBD-X which improves convergence for waterjet pumps. Because past PBD-14 predictions for waterjet pumps have not been accurate, it is hoped that the predictions from PBD-X will be better. However, further development of PBD-X is required before more detailed conclusions can be made. A postprocessor for PBD-X has been written to create the input files for BSHAPE, a blade shape design program developed for use with PBD-14. This will support the creation of a design capability using PBD-X. MTSET, the grid generation component of MTFLOW, has been modified to include additional grid spacing options. This will greatly improve the usability of MTSET and the quality of the throughflow grids while maintaining the current ease of use.
- Computer Programming and Software
- Fluid Mechanics