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One popular way to decrease the pump’s axial force is by utilizing the back blade. In this paper, by changing the number and width of back blades and using CFD 3D simulation technology, the influence law of back blades on pump performance, pump chamber liquid pressure characteristics and axial force characteristics is obtained. By changing the number of the back blade and width of the back blade, this paper adopt CFD 3D simulation technology to study, get pump performance, pump cavity liquid pressure characteristic and the influence law of axial force characteristics. The results show that the pump head and power increase with the increase of the width and number of back blades. However, the efficiency of the pump gradually decreases with the increase of the width and number of back blades. The impeller mounted back blade can change the pressure distribution of liquid of the pump chamber, and affect the axial force of the pump. The size and direction of the axial force change with the number and width of the back blades.

This paper numerically investigates the hydraulic performance and axial force of a low specific speed centrifugal pump in the turbine mode using the k - ω SST model. Numerical results are validated against the experimental data in the literature and a good agreement is observed. Results show that the rotation factor increases by flowrate, since the head, which is directly proportional to the transferred circumferential momentum, increases by the flowrate in the turbine mode. Moreover, values of rotation factors on both sides varies in radial direction due to geometrical parameters and, they reduce where larger axial gaps are present. Additionally, the pressure distributions on the hub and shroud sides are correlated with rotation factors on these areas. Interestingly, the axial position of the impeller plays an important role in the axial force of the PAT. By applying impeller movement of 5 mm from its original position, the point of zero axial force has shifted to higher flowrates and the maximum axial force is reduced 50%. Finally, with 10 mm movement of the impeller, the axial force exhibits distinct behavior so that its direction is preserved and, the returned magnitude is almost constant in the working range by 60% decrease in the maximum axial force.

This paper presents selected results of numerical and analytical analysis of a traditional design of an axial force balancing system in a multistage centrifugal pump. The value of the axial force generated in the face throttle of such a system is directly influenced by the geometry of the throttles: length and height. In the process of operating a multistage pump, the surfaces that form the face throttle are deformed due to high values of pressure or temperature. Changing geometry results in a change in the pressure distribution, and thus in the value of the generated axial force and hydraulic losses. The analytical approach provides a simplified theoretical estimation of disc deflection and force balance, while the numerical simulations capture the detailed pressure distribution and corresponding structural response for different face gap values. The practical value of this research lies in providing a deeper understanding of the relationship between balance disc deformation and axial force. The results enable more accurate selection of disc geometry and face gap value, helping to minimize residual thrust on bearings and hydraulic losses on the automatic balancing device.

Axial flow pumps often experience uneven distribution of axial force on the blades when deviating from design conditions, which can easily lead to local damage to the pump blades. In response to this issue, this article conducts a detailed study on the hydraulic and axial force characteristics of large vertical axial flow pumping stations in China based on constant and non-constant numerical simulation research methods. Research has found that under biased operating conditions, due to the angle between the water flow direction inside the impeller and the impeller blades, the water body collides with the blades, resulting in concentrated pressure distribution on both sides of the inlet side of the impeller blades. Under low flow conditions, the high axial force area of the impeller blade is concentrated in the middle and rear position of the suction surface, while under high flow conditions, the high axial force area is widely distributed. Under the conditions of 0.8 Q to 1.4 Q , the fluctuation of axial force on the impeller blades is mainly affected by the rotation of the impeller blades. However, under low flow conditions, due to the turbulence of the flow state, there is no obvious pattern of axial force variation on the impeller blades. In addition, under different flow conditions, there is no obvious pattern in the fluctuation of axial force on the guide vanes. This also proves that there are problems such as uneven axial force distribution and no periodic changes in the impeller blades under low flow conditions, which can easily lead to damage to the impeller blades. The above analysis can provide some reference for the design of impeller blades.

In order to investigate the coordinated relationship between lateral deformation of the diaphragm wall and axial force of the internal strut, this paper first carried out a scaled model test on the mechanical features of a foundation pit support system based on a novel axial force servo device. Then, a finite element model was established to simulate the scaled model test, and the correctness of the finite element modeling approach was validated by comparing test results. After that, the same finite element modeling method was used to analyze the coordinated relationship between axial force and lateral deformation in the prototype foundation pit support structure. The results show that the axial force of the inner strut is negatively correlated with the lateral deformation in the diaphragm wall. The initial maximum lateral deformation in the diaphragm wall of the shaft foundation pit occurs at the bottom of the foundation pit, so changing the length of bottom strut simultaneously is the most effective way to adjust the mechanical behavior of the support structure. Under various support conditions, the maximum lateral deformation of the diaphragm wall in the prototype project is 0.59~0.66‰ of the total excavation depth of the foundation pit, and the maximum axial force of internal support is 11~30% of the yield load of a single steel strut.

The cage, serving as a pivotal element in rolling bearings, possesses dynamic characteristics that have a direct bearing on the overall performance of the bearing. This paper caters to the requirements of dynamic and strength analysis of the four-point contact ball-bearing cage in high-speed railway traction motors. A rigid-flexible coupling dynamics model of the bearing is established on the ADAMS platform and its dynamic analysis was carried out under variable axial forces and with different guiding clearances. The results show that the variable axial force has little effect on the bearing cage stress, but has a great effect on the bearing cage motion. The guiding clearance has little effect on the stress of the cage, but it affects the displacement and speed of the cage obviously.

The FSW process parameters for dissimilar welding of AISI 410S and 304L stainless steels were meticulously varied to achieve a combination of excellent surface finish, zero voids, and complete tool penetration. These crucial findings have far-reaching practical implications, providing valuable guidance for the welding industry to attain optimal results. In-depth preliminary tests were conducted to determine the precise positioning of the steels between the advancing and retreating sides. During welding, axial forces ranging from 25 to 40 kN were rigorously applied while maintaining a constant rotational speed of 450 rpm and welding speed of 1 mm/s. Considering the welded steels' distinct physical and chemical properties, positioning AISI 410S ferritic stainless steel on the advancing side resulted in a noticeable reduction in flash production and void formation in the stir zone. It was observed that as the axial force increased, there was a proportional rise in flash production, particularly accentuated on the advancing side compared to the retreating side. Nonetheless, this increase in axial force led to a reduction in material insertion size, effectively eliminating flaws at the joints' roots. The research demonstrates the feasibility of producing dissimilar joints between AISI 410S and 304L stainless steels via the FSW process, yielding exceptional surface finish and defect-free stir zones.”

A numerical analysis is improved to study the effect of vibration on temperature history, heat generation, and mechanical properties during the friction stir welding process with different welding speeds. In this investigation, smoothed particle hydrodynamics (SPH) was applied to improve the 3D numerical analysis for simulation of the friction stir welding (FSW) process and friction stir vibration welding (FSVW) under different welding speeds. According to the experimental analysis, the grain size of the FSVW-ed sample is finer compared with that of the FSW-ed sample. The analysis was validated through a comparison of the simulated thermal cycles with the experimental results. There was a close agreement between FEM and experimental values. The results indicated that the vibration increased the mechanical properties such as von Misses stress and also thermal properties of the FSW-ed sample. The vibration in the FSW process can lead to an enhanced plastic material flow and also improve the weld quality by enhancing the plastic material flow near the tool. The shear zone volume (SZV) develops from 289.56 mm 3 for the FSW process to 367.34 mm 3 for the FSVW process. It was found that the axial forces, traverse force, and tool torque with respect to different steps (plunging, preheating, or dwelling time and traveling) in FSVW is lower than those in the FSW.

This study investigates the effects of a back plate preheating assistance system and deep rolling (DR) on axial force and tunnel defects during friction stir welding (FSW). Different preheating configurations—advancing side (AS), retreating side (RS), and both sides—were examined to evaluate their impact on axial force reduction, temperature distribution, and defect minimization. Axial force measurements were taken using a dynamometer, and temperature histories were recorded with a thermal camera. The results demonstrate that a preheating temperature of 200 °C is optimal, reducing axial force by 30.24% and enhancing material flow. This temperature also facilitated deeper tool penetration, especially when preheating was applied to both sides. Preheating on the AS resulted in the smallest tunnel defects, reducing defect size by 80.15% on the RS and 96.91% on the AS compared to the non-preheated condition. While DR further reduced tunnel defects, its effectiveness was limited by the proximity of defects to the surface. These findings offer significant insights for improving the FSW process.

Centrifugal pumps can feasibly act as turbines in small hydropower plants. However, prediction and reduction methods of axial force is still challenging. A proposed method to this goal is the use of balancing holes. Accordingly, this paper investigates the effect of balancing holes diameter on the hydraulic performance and the axial force of a centrifugal pump as turbine (PAT). In this study, modeling of the fluid flow within the pump was carried out by using the commercial software of Ansys CFX R19.0 and the SST turbulence model. The numerical results showed that by working in the reverse mode, the operating flowrate, head and the axial force of the pump are increased remarkably. This study proved that drilling balancing holes in the impeller, despite being simple, is a useful method in reducing the axial force and has minor effects of the output power. Results showed that by drilling a hole of diameter 2 mm, the axial force is approximately decreased by 60 % in almost all flowrates. Finally, it is observed that increasing holes diameter is mostly influential at high flowrates, and with diameter of 6.5 mm, the axial force is reduced about 90%.