# Improving the Design of a Multi-Gear Pump Switchgear Using CFD Analysis
## 4 Conclusions  
This paper describes a numerical model that allows the characteristics of fluid motion characteristics in a gear pump, taking into account the viscosity and design characteristics of the inlet orifice system.  
The following results were obtained:  
1. Cavitations were observed in the upper cover of the manifold with a transition radius of 3 mm.
2. Reducing the transition radius in the manifold from 3 to 15 mm in the suction line of the system reduces the pressure drop by 13%.
3. The liquid flow velocity in the top cover of a multiple gear pump decreases slightly (3%) as a function of changing the radius in the manifold from 3 to 15 mm.
4. The minimum pressure on the suction line is 500 kPa or more. Smaller pressures contribute to the interruption of the continuity of the liquid flow and the occurrence of cavitation.
5. Fluid viscosity and drive shaft speed also influence the performance of the multiple gear pump design.
6. It is established that with this distribution system, taking into account the variable temperature of the liquid in the hydraulic circuits, the multiple gear pump can operate with liquids belonging to a viscosity class of 5-10.
7. The rotational speed is not greater than 1200 rpm with a kinematic viscosity coefficient of 10 cSt.
8. The pressure drop depends on the number of revolutions and the radius of the rounding of the manifold.  
This study has certain limitations that are related to the sensitivity of the mesh in the modeling process. In future studies, we intend to address these shortcomings by tuning the mesh in manual mode and increasing the number of cells.  
Future work is also planned to improve the fluid distribution system in the multistage pump, particularly to consider the possibility of making suction holes in the pump casing. This will reduce suction line losses and increase the range of liquids pumped.  
It is expected that this study will be a useful reference for design engineers and developers who will be able to apply the results to obtain different flow parameters for a multi-gear pump.  
Conceptualization, L.G. and O.Z.; methodology, O.Z., L.G. and T.N.; software, O.R.; validation, L.G., O.Z. and A.B. ([PERSON]); formal analysis, O.Z. and T.N.; investigation, O.N., A.B. ([PERSON]) and A.B. ([PERSON]); resources, O.Z. and A.B. ([PERSON]); data curation, L.G. and T.N.; writing--original draft preparation, O.Z., O.R., L.G., L.W., B.W., W.L. and O.N.; writing--review and editing, O.Z., L.G., L.W. and B.W.; visualization, O.R. and A.B. ([PERSON]); supervision, O.Z. and L.G.; project administration, T.N. and L.G. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant of Young Scientists IRN No. AP19579208 \"Creation of a universal prototype of a gear pump for hydraulic systems capable of pumping viscous liquids of various nature\") for the analysis of the design and technological features of gear pumps.  
Not applicable.  
Data Availability Statement: Data are contained within the article.  
The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.