The article "Scale effect features during simulation tests of 3D printer-made vane pump models" discusses the influence of scale effect on translation of pump parameters from models, made with 3D-prototyping methods, to full-scale pumps. Widely spread now 3D-printer production of pump model parts or entire layouts can be considered to be the main direction of vane pumps modeling. This is due to the widespread development of pumps in different CAD-systems and the significant cost reduction in manufacturing such layouts, as compared to casting and other traditional methods.

The phenomenon of scale effect in vane hydraulic machines, i.e. violation of similarity conditions when translating pump parameters from model to full-scale pumps is studied in detail in the theory of similarity. However, as the experience in the 3d-printer manufacturing of models and their testing gains it becomes clear that accounting large-scale effect for such models has a number of differences from the conventional techniques. The reason for this is the features of micro and macro geometry of parts made in different kinds of 3D-printers (extrusive, and powder sintering methods, ultraviolet light, etc.).

The article considers the converting features of external and internal mechanical losses, leakages, and hydraulic losses, as well as the specifics of the balance tests for such models. It also presents the basic conversion formulas describing the factors affecting the value of these losses. It shows photographs of part surfaces of models, manufactured by 3D-printer and subjected to subsequent machining. The paper shows results of translation from several pump models (layouts) to the full-scale ones, using the techniques described, and it also shows that the error in translation efficiency does not exceed 1.15%. The conclusion emphasizes the importance of the balance tests of models to accumulate statistical data on the scale effect for pump layouts made by different 3D-prototyping methods since their conversion factors may vary.