scholarly journals Research on Quality Control of Precision Machining Straight Internal Gear by Abrasive Flow Based on large Eddy Simulation

Author(s):  
Tiangang Zou ◽  
Qingdong Yan ◽  
Lixiong Wang ◽  
Yuanyuan AN ◽  
Jiyong qu ◽  
...  

Abstract Traditional finishing technology is difficult to realize the precision machining of complex geometric parts. Abrasive flow machining technology solves this problem well. Taking the spur internal gear as the research object, the wall shear force, static pressure, dynamic pressure and abrasive velocity vector of the internal channel of the straight internal gear under different inlet velocity, abrasive concentration and abrasive particle size are analyzed by using the large eddy simulation method, and the action law of different parameters on the machining of straight internal gear by solid-liquid two-phase abrasive flow is discussed. At the same time, orthogonal test was carried out. The results show that the solid-liquid two-phase abrasive flow machining technology can effectively remove the burrs, pits and bulges on the tooth surface of spur internal gear, reduce the tooth surface roughness and improve the surface quality. The optimal combination of processing parameters and the primary and secondary order of various factors affecting processing are obtained by range analysis and analysis of variance. The regression equation is constructed by regression analysis to verify the effectiveness and accuracy of the model, which provides theoretical support and data reference for actual processing and production.

Author(s):  
Junye Li ◽  
Ningning Su ◽  
Lili Wei ◽  
Xinming Zhang ◽  
Yanlu Yin ◽  
...  

To study the surface forming mechanism of the solid–liquid two-phase abrasive flow processing, the large eddy simulation method was used. Taking a 90° stainless steel elbow as the research object, the action mechanism of the dynamic pressure, wall shear force, flow state of the abrasive flow at different cross-sections, formation of the vortex, and trajectory of the abrasive flow on the inner surface of the elbow with abrasive flow composed of solid-phase silicon carbide and liquid-phase hydraulic oil are discussed. This study explores the distribution characteristics of the flow pattern of solid–liquid two-phase abrasive flow. Moreover, the wear and erosion of the abrasive grain and the wall of the workpiece are discussed. The mechanism of surface formation of solid–liquid two-phase abrasive flow is revealed.


2020 ◽  
Vol 19 (3-5) ◽  
pp. 207-239
Author(s):  
Saman Salehian ◽  
Reda R Mankbadi

The focus of this work is on understanding the effect of water injection from the launch pad on the noise generated during rocket’s lift-off. To simplify the problem, we consider a supersonic jet impinging on a flat plate with water injection from the impingement plate. The Volume of Fluid model is adopted in this work to simulate the two-phase flow. A Hybrid Large Eddy Simulation – Unsteady Reynolds Averaged Simulation approach is employed to model turbulence, wherein Unsteady Reynolds Averaged Simulation is used near the walls, and Large Eddy Simulation is used elsewhere in the computational domain. The numerical issues associated with simulating the noise of two-phase supersonic flow are addressed. The pressure fluctuations on the impingement plate obtained from numerical simulations agree well with the experimental data. Furthermore, the predicted effect of water injection on the far-field broadband noise is consistent with that of the experiment. The possible mechanisms for noise reduction by water injection are discussed.


2019 ◽  
Vol 208 ◽  
pp. 115156 ◽  
Author(s):  
Mohammad Haji Mohammadi ◽  
Fotis Sotiropoulos ◽  
Joshua R. Brinkerhoff

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