# Numerical Calculation and Experimental Study of the Axial Force of Aero Fuel Centrifugal Pumps
## 5 Conclusions  
In this paper, taking an aero fuel centrifugal pump as the research object, the axial force of the impeller component was calculated by numerical simulation and experimental methods, respectively, to verify the accuracy of numerical calculation. Combined with the simulation and experimental results, the theoretical calculation formula of axial force was modified.  
The static pressure in the pump chamber gradually increases along the rotation direction of the impeller because the volute of the centrifugal pump converts the kinetic energy of the liquid part into static pressure energy. Through numerical simulation, it is found that the pressure of the front and rear pump chambers of the fuel centrifugal pump presents a circumferential uneven distribution under the influence of dynamic and static interference. Moreover, the area of the rear pump chamber is larger than that of the front pump chamber and the pressure of the rear chamber below the mouth ring is far above the inlet pressure of the impeller, which is the primary reason for the axial force of the impeller in the centrifugal pump.  
The position servo force measuring system used in the test avoids the influence of high-speed rotation of the transmission shaft on the force measurement, relieves the coupling influence of the measurement process on the work of the pump, and ensures the accuracy of the online direct measurement of the axial force of the working impeller in the fuel centrifugal pump. By comparing the numerical results with the experimental values, the following conclusions are drawn:  
1. The axial force of the centrifugal impeller accounts for the main part of the total axial force, while the axial force of the induction wheel is relatively small due to its weak pressurization ability. Under the condition of constant outlet throttling state, the axial force of the fuel centrifugal pump increases with the increase in the rotational speed and the slope of the curve also increases obviously in the process of increasing;
2. The variation trend of the simulated axial force obtained by the numerical simulation method is roughly the same as that of the experimental value and the maximum error is 9.7%. The simulation method can accurately predict the axial force of an aero fuel centrifugal pump;
3. The axial force of the centrifugal pump calculated by the traditional theoretical formula has a large error, while the error between the calculated value obtained by the modified formula and the experimental value is within 9.88%, indicating that the modified formula can accurately calculate the axial force of the fuel centrifugal pump.  
The contributions of all the authors to this manuscript are as follows: Conceptualization, S.Y. and Y.K.; methodology, S.Y.; software, S.Y. and X.L.; validation, S.Y., Y.K. and L.X.; formal analysis, S.Y.; writing--original draft preparation, S.Y. and L.X.; writing--review and editing, S.Y. and X.L.; supervision, Z.Y.; project administration, Z.Y. All authors have read and agreed to the published version of the manuscript.  
This manuscript was funded by the National Natural Science Foundation of China, grant number 62373185.  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
Acknowledgements to AECC Guizhou Honglin Aero-Engine Control Technology Co., Ltd., for support of the test site and equipment for this research subject.  
Author [PERSON] was employed by AECC Guizhou Honglin Aero-Engine Control Technology Co., Ltd. Author [PERSON] was employed by AVIC Jincheng Nanjing Engineering Institute of Aircraft System. The remaining authors declare that the research was conductedin the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.