scholarly journals Investigation of axial thrust deviation between the theory and experiment for high-speed mine submersible pump

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401878925 ◽  
Author(s):  
Bin Xia ◽  
Fanyu Kong ◽  
Hui Zhang ◽  
Lei Yang ◽  
Wanghuan Qian
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
High Speed ◽  
Performance Test ◽  
Submersible Pump ◽  
Axial Thrust ◽  
Pressure Surface ◽  
Pump Stage ◽  
Reliability Performance ◽  
Theory And Experiment

In this article, three types of high-speed mine submersible pumps were designed and experimented. During the reliability performance test, the axial thrust balancing device of GFQ150-700 was overloaded and damaged due to an unsuitable designed value of axial thrust. The designed hydraulic axial thrust with the actual value is compared in this article, and the reason for axial thrust deviation is discussed. Results show that axial thrust of the theoretical calculation is close to the numerical simulation value at a certain extent. GFQ100-1000 obtains the maximum theoretical axial thrust, while the maximum simulated value is produced in GFQ150-700, and that is corroborated by experiments. The axial blade force is related to the pump stage and area differences between the blade suction and pressure surface. Due to the increasing stage in GFQ100-1000, the axial blade force increases to a remarkable value in an opposite direction with respect to GFQ150-700. The opposite blade force offsetting other hydraulic forces in GFQ100-1000 is responsible for the maximum hydraulic axial thrust emerges in GFQ150-700 instead of GFQ100-1000.

Calculation of Axial Hydraulic Thrust of Francis Turbine

2012 ◽  
Author(s):  
XingYing Ji ◽  
Lai Xu ◽  
Xiao Liu
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Significant Role ◽  
Model Test ◽  
Francis Turbine ◽  
Axial Thrust ◽  
Theoretical Methods ◽  
Calculation Results

Put forward a method of calculating the axial thrust of Francis turbine. To use numerical simulation computing the axial thrust on hub, shroud and blade of inner runner, combine theoretical methods calculating the pressure on hub and shroud of outer runner, finally the axial thrust of Francis turbine is obtained. The results of calculation agree with the results of model test. It is an effective way of gathering the theoretical calculation and numerical simulation to calculate the axial thrust of Francis turbine. In addition the static suction of turbine has great effect on calculation results of the axial thrust. The static suction of turbine plays a significant role on the lifting of turbine.

Study on Dynamic Pressure Effect of Gas Bearings in Fuel Cell Vehicles

2020 ◽  
Author(s):  
Chenxin Zhang ◽  
Weirong Hong ◽  
Shuiying Zheng
Keyword(s):  
Numerical Simulation ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Performance Test ◽  
Pressure Effect ◽  
Dynamic Pressure ◽  
Simulation Method ◽  
Dynamic Mesh ◽  
Gas Bearings ◽  
Cfd Numerical Simulation

Abstract The dynamic pressure effect can contribute to a better working performance of the gas bearing without changing its overall structure or increase its air supply pressure. To study the dynamic pressure effect of gas bearings, a new method of CFD numerical simulation with self-developed UDF dynamic mesh program was proposed. In this way, values of dynamic characteristics for gas bearings with different fluid fields and under different working conditions can be calculated. Based on the numerical simulation results, the influence law of rotational speed, gas film thickness, and radial eccentricity ratio on the dynamic characteristics (load-carrying capacity, stiffness and damping coefficients, static equilibrium position etc.) were obtained. Afterwards, a bearing’s performance test was conducted on a rotor-bearing system in the high-speed air compressor. Compared to the traditional methods, after the dynamic pressure effect was taken into account, the corresponding rotor dynamic calculation of critical speed is more in accordance with the experimental results, thus proved the credibility of the new CFD numerical simulation method with dynamic mesh.

Numerical simulation of high-speed civil transport inlet operability with angle of attack

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 1223-1229
Author(s):  
Ge-Cheng Zha ◽  
Doyle Knight ◽  
Donald Smith ◽  
Martin Haas
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Angle Of Attack

Numerical Simulation of High-Speed Crack Propagating and Branching Phenomena

2016 ◽  
Vol 37 (7) ◽  
pp. 729-739
Author(s):  
GU Xin-bao ◽  
◽  
ZHOU Xiao-ping ◽  
XU Xiao ◽  
Keyword(s):  
Numerical Simulation ◽  
High Speed

scholarly journals Research on Performance Test System of Space Harmonic Reducer in High Vacuum and Low Temperature Environment

Machines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Jing Wang ◽  
Zhihua Wan ◽  
Zhurong Dong ◽  
Zhengguo Li
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Performance Test ◽  
High Reliability ◽  
High Vacuum ◽  
Test System ◽  
Low Noise ◽  
Speed Ratio ◽  
Space Harmonic ◽  
Temperature Environment

The harmonic reducer, with its advantages of high precision, low noise, light weight, and high speed ratio, has been widely used in aerospace solar wing deployment mechanisms, antenna pointing mechanisms, robot joints, and other precision transmission fields. Accurately predicting the performance of the harmonic reducer under various application conditions is of great significance to the high reliability and long life of the harmonic reducer. In this paper, a set of automatic harmonic reducer performance test systems is designed. By using the CANOpen bus interface to control the servo motor as the drive motor, through accurately controlling the motor speed and rotation angle, collecting the angle, torque, and current in real time, the life cycle test of space harmonic reducer was carried out in high vacuum and low temperature environment on the ground. Then, the collected data were automatically analyzed and calculated. The test data of the transmission accuracy, backlash, and transmission efficiency of the space harmonic reducer were obtained. It is proven by experiments that the performance data of the harmonic reducer in space work can be more accurately obtained by using the test system mentioned in this paper, which is convenient for further research on related lubricating materials.

scholarly journals The Influence of the Axial Rub Added in the Radial Rub on the Wear of the Seal Fins during the High Speed Rub of Labyrinth-Honeycomb Seal

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1997
Author(s):  
Bin Lu ◽  
Haijun Xuan ◽  
Xiaojian Ma ◽  
Fangjun Han ◽  
Weirong Hong ◽  
...  
Keyword(s):  
Wear Rate ◽  
High Speed ◽  
State Of The Art ◽  
Negative Influence ◽  
Axial Thrust ◽  
Cross Sectional ◽  
Honeycomb Seal ◽  
Aero Engine ◽  
Honeycomb Seals ◽  
Clearance Change

Labyrinth-honeycomb seals are a state-of-the-art sealing technology commonly used in aero-engine interstage seal. The undesirable severe rub between the seal fins and the honeycomb due to the clearance change may induce the cracking of the seal fins. A pervious study investigated the wear of the seal fins at different radial incursion rates. However, due to the axial thrust and mounting clearance, the axial rub between the seal fins and the honeycomb may occur. Hence, this paper focuses on the influence of the axial rub added in the radial rub on the wear of the seal fins. The rub tests results, including rubbing forces and temperature, wear rate, worn morphology, cross-sectional morphology and energy dispersive spectroscopy results, are presented and discussed. Overall, the participation of the axial rub leads to higher rubbing forces, temperature, and wear rate. The tribo-layer on the seal fin is thicker and the cracks are more obvious at high axial incursion rate. These phenomena indicate the axial rub has a negative influence on the wear of the seal fins and should be avoided.

Numerical Simulation of Flowfield around High Speed Trains Passing by each other at the same Speed

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Point Source ◽  
High Speed ◽  
Stokes Equations ◽  
Field Structure ◽  
Vehicle Speed ◽  
Mesh Method ◽  
High Speed Trains

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.

Sign in / Sign up

Export Citation Format

Share Document