Session: 06-03-01 Fluid-Structure, Multi-body and Wave-body Interaction/Professor Calisal Honoring Symposium

Submission Number: 155321

Aerodynamic Optimization of In-Line and Parallel Layouts for Symmetric Cambered Wingsail Installation 

Rigid wingsails are an established design for thrust generation on large commercial ships. Specifically, efficiency improvements have been found for wingsails with sectional profiles using camber that is symmetric about the middle of the chord.

This study aims to identify effective installation layouts for multiple wingsails to maximize practical thrust generation. Aerodynamic interference effects among the wingsails are computed using a fast 2D potential-flow method, which is validated against previous 3D high-fidelity simulation data in terms of lift and drag forces. Two typical layouts are considered, that is, triple sails arranged in line and quad sails in parallel. The layouts are optimized using the Kriging-based optimization method, with the objective to achieve the largest thrust at apparent wind angles (AWAs) of 30°, 60°, and 90°. The optimized parameters are the distances between the sail units. Then, the optimization results are analyzed to understand how the distances affect lift and drag forces, as well as the wake development from each sail.

The two layouts are evaluated in terms of the average thrust per sail, the force differences between the sails, and the pressure distributions on the surfaces in reference to an individual sail. We find that upstream sails consistently generate greater thrust than downstream ones. The reason is mainly associated with local induced apparent wind angle.

Another interesting finding is that for the triple in-line layout, the middle sail generates the lowest thrust. Moreover, the thrust generation is dependent on the apparent wing angle. It means that the down-selection of the optimal distances should be determined by analyzing the aerodynamic performance at different wind conditions instead of simply at a specific apparent wind angle.

Finally, unfavorable and favorable conditions for the thrust generation are discussed. These findings provide insights on installation layouts for the thrust generation from multiple wingsails.

ACKNOWLEDGEMENTS

This research was conducted in the project “GEMINI” (generic multidisciplinary optimization for sail installation on wind-assisted ships) funded by the Swedish Transport Administration. We appreciate the internship student, Laryns Keurtys Leutchap Mbiatat, for his contribution to coding. The computations and data handling were enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS), partially funded by the Swedish Research Council through grant agreement no. 2022-06725.

REFERENCES

[1] H. Zhu, V. Chernoray, J. W. Ringsberg, H.-D. Yao, B. Ramne. “Experimental study on structure responses of triple wing sails to turbulence flows at multiple yaw angles”. Advances in the Analysis and Design of Marine Structures – Proceedings of the 9th International Conference on Marine Structures (MARSTRUCT 2023), Gothenburg, Sweden, April 3-5, 2023. DOI: 10.1201/9781003399759-86

[2] H. Zhu, H.-D. Yao, F. Thies, J. W. Ringsberg, B. Ramne, Propulsive performance of a rigid wingsail with crescent-shaped  profiles, Ocean Engineering, 285(2), 115349, 2023, ISSN 0029-8018, https://doi.org/10.1016/j.oceaneng.2023.115349.

[3] H. Zhu, H.-D. Yao, J.W. Ringsberg, Unsteady RANS and IDDES studies on a telescopic crescent-shaped wingsail, Ships and Offshore Structures, 2023. DOI: 10.1080/17445302.2023.2256601

[4] P.D. Sharpe, Accelerating Practical Engineering Design Optimization with Computational Graph Transformations, PhD thesis, Massachusetts Institute of Technology, 2024.

[5] P.D. Sharpe, AeroSandbox: A Differentiable Framework for Aircraft Design Optimization, Massachusetts Institute of Technology, 2024.

Presenting Author: Hua-Dong Yao Chalmers University of Technology

Presenting Author Biography: Hua-Dong Yao has dedicated his research in general on renewable energy and clean transport from the perspective of fluid-structure interaction (FSI). The time can be traced back to his PhD thesis, which was completed in 2008. In collaboration with his colleagues and students in/outside Chalmers University of Technology, he has been developing many specific methods and tools to resolve critical fundamental and industrial problems. He is a member of AIAA, SAE International, RINA, and ICNMT.

Now he is also a member of ICES (International Council for the Exploration of the Sea) nominated from Sweden. In the Working Group on Offshore Renewable Energy (WGORE) of ICES, he is dedicated to investigating the hydrographic impacts of offshore wind farms on ocean environments.

He has held a guest professorship at several universities. He has served as a guest editor of several scientific journals, and a member of the organizing committee of several international conferences in aerospace and marine technology. He has been invited as a keynote speaker to conferences and workshops. He has led projects funded by Horizon 2020 and Swedish national funding bodies. He has participated in the Horizon 2020 projects, for example, ALONOCO, CALAS, IMAGE, SUBLIME, and IVANHOE (the coordinator).