Abstract:

Motivation:
Printing objects could aid in the fields of Turbomachinery or Advanced Fluid Mechanics to the understanding of the complex structures.

Introduction:
Many disciplines in Engineering need advanced knowledge in Fluid Mechanics to understand the processes that take place. The Turbomachinery case fits very well with this statement since the structure of the fluid field is closely related to the efficiency of the system. Engineers must know in detail the typical structure of the fluid field and be able to infer how it will change when the design is modified. However, the fluid field is very complex and its understanding requires high doses of abstraction and spatial vision.
The main aim of this project is to show the fluid field that appears around different blades in different conditions using 3D printed objects that combine the geometry of the machine and the structure of the flow.

Procedure:
In order to achieve the proposed objectives, it is necessary to carry out a set of highly specialized chained processes that require specific training. The steps are the following:
1- Preparation of the model: Firstly, the blade geometry and the topology have to be defined and the domains have to be meshed to be able to run the numerical simulation.
2- Structure identifier: A simulation software is used to identify the different structures obtained in the previous numerical simulation.
The next step is to export the file in a .STL format.
3- Handling the objects: It is essential to process the format obtained previously in order to accomplish one didactic requirement as deleting the structures different from the ones we were looking for that could have been appeared due to the numerical simulation method used and one technological requirement as generating better 3D printing supports, reducing the printing time.
4- Printing: The printing technology is chosen.

Lessons learned:
A pilot experience has been carried out and the first objects have been printed, with which some important aspects have been identified:
• It is necessary to use high quality simulations.
• One of the critical points of the procedure is to define well the identification algorithms.
• The handling of objects is a very manual activity that requires high attention and work time. However, it is a crucial task because it allows introducing a great amount of didactic aspects in the printed objects.
• The available hardware conditions some important aspects in the steps followed.

Future work and conclusions:
Showing the objects as an example in the lessons or asking what the student is seeing and why this structure has been formed are some useful applications for the resulting objects in teaching. Developing the necessary documentation is essential to use effectively these models.
The project proposes the use of advanced techniques as 3D printing to improve and streamline the student´s comprehension process of complex phenomena.

References:
[1] Wu, B., Chen, G. H., Fu, D., Moreland, J., Zhou, C. Q., Guo, L. y Wang, Y. (2010). Integration of Virtual Reality with Computational Fluid Dynamics for Process Optimization.
[2] S. Ford, T. Minshall. 2017. 3D printing in teaching and education: A review of where and how it is used.
[3] O. Knill, E. Slavkovsky. Illustrating mathematics using 3D printers.
[4] H. Lipson, F. C.Moon, J. Hai, C. Paventi. 3D-Printing the History of Mechanisms.

Keywords:

Additive manufacturing, 3D-Printing, 3D objects, Turbomachinery, Teaching material development.