## 4 Conclusions  
The analysis and validation of a tool capable of linking an enlarged scaled model of a turbine without rotor and a conventional radial turbine is the main objective of this study. The aim is to check the flow behavior in the volume and stator of the scaled model and compare it with what is predicted in a real turbine model. The model of the real turbine was validated with general outputs, those that can be measured in a conventional turbocharger test bench. The computational model of the scaled, rotor-less turbine matches the performance of the real-sized turbine model. This study set the basis of a work methodology that would allow studying flow patterns. Experimental testing of the scaled model would conclude the accuracy of the predictions in the inner channels of the stator and tip gap for different configurations, since it was concluded that the lack of rotor has little impact in flow patterns in the stator vanes. The current turbine measuring methodology mainly involves measuring inlet and outlet conditions, while the scaled printed model alongside the presented computational modeling would allow much better experimental results. By analyzing the results, the interaction between rotor and stator was quantified, that is, the flow at the stator that became affected by the presence of the rotor is higher as the channel between vanes is broader. However, it was shown how, for a wide variation of VGT positions, the lack of rotor does affect the analysis on flow behavior through the stator. This has implications in future studies focusing on the stator of a turbine, since discarding the rotor in numerical simulations saves a huge amount of computational cost. The complexity and cost that entail the implementation of a rotor in the 3D printed model make it necessary to check the interaction between the stator and the rotor. For the two vane openings shown in this study, VGT30 and VGT60, the consistency between the scaled and the real models is high in the stator region. Under these results, further analysis can be performed on how other characteristics of the real turbine affected the performance of the stator, for example, the screws that cross the stator in the spanwise direction. Another point of interest could be how the pressure coefficient had significant discrepancies between different nozzle openings, but not so much between different flow conditions, as the different similarities simulated showed. Regarding the study of the clearance left between the vane tip and the upper stator wall, it was justified that keeping the Reynolds number is a valuable way to represent the phenomena, as the CFD model of the real turbine does. Thus, it was shown how outlet flow angle through the tip had little variation whether there is a rotor or not downstream from the stator vanes. Some discrepancies appeared when studying local Reynolds number in the tip, but taking into account the viscous nature of the flow over it and how much could it be affected by slight differences, such as the tip vane shape itself, the results showed good  
Figure 15: Velocity convoluted vectors for different chord lengths. ST; VGT30 and VGT60; 0.5 and 1.5 mm tip height. agreement having similar Reynolds number at the same chord percentages and similar distribution shapes through the length of the gap. Moreover, two different clearances heights were simulated and compared for the scaled model, showing that this gap should be minimized to decrease tip leakage losses. This action gains interest if the desire is to work under small nozzle openings, and its influence is shown to be lower for broader positions. Conceptualization, J.A.L.-C. and A.O.T. ; methodology, J.A.L.-C. and N.H.-G.; software, J.A.L.-C.; validation, A.O.T., J.A.L.-C. and N.H.-G.; formal analysis, J.R.S. ; investigation, J.A.L.-C. and N.H.-G.; resources, A.O.T. and N.H.-G.; data curation, J.A.L.-C.; writing--original draft preparation, J.A.L.-C., A.O.T. and N.H.-G.; writing--review and editing, J.R.S. ; visualization, J.A.L.-C.; supervision, J.R.S.