Numerical Simulation and Structure Optimization of the Main-Control Reversing Valve of Electrical-Hydraulic Hammer

2008 ◽  
Vol 575-578 ◽  
pp. 180-185
Author(s):  
Shi Wen Du ◽  
Yong Tang Li

Based on viscosity hydrodynamics and hydro-finite element theory, flow field of the main-control reversing valve of electrical-hydraulic hammer was simulated. The N-S equations were discretized by the finite volume method. Hydraulic valve’s pressure and velocity distribution were analyzed in the working process. Relationship between the structure of the flow field (velocity, pressure, flow separation and reattachment, appearing and disappearing of vortices) and the energy loss and component performance was proposed. The design of the hydraulic valve structure was optimized which turns out to be high-efficiency and energy-saving

2014 ◽  
Vol 1046 ◽  
pp. 209-212
Author(s):  
Liang Li

Introduces the structure and main characteristics of high efficiency low resistance cyclone dust removal, the use of fluid finite element analysis software for the internal flow field is simulated. It can be concluded that gas flow in the cyclone separator, pressure field, velocity field, such as distribution, and on the basis of the flow field calculation results for the structure design about analyzed and discussed.


Author(s):  
Shitao Shen ◽  
Zichuan Yi ◽  
Xing Li ◽  
Shuting Xie ◽  
Mingliang Jin ◽  
...  

Author(s):  
Angela O. Nieckele ◽  
Luis Fernando Figueira da Silva ◽  
Joa˜o Carlos R. Pla´cido

Thermal spallation is a possible drilling technique which consists of using hot supersonic jets as heat source to perforate hard rocks at high rates. This work presents a numerical analysis of a typical spallation drilling configuration, by the finite volume method. The time-averaged conservation equations of mass, momentum and energy are solved to determine the turbulent compressible gas phase flow field. Turbulence is predicted by the classical high Reynolds number κ-ε model, as well as with a low Reynolds number κ-ε model. The influence of the jet Reynolds number is investigated. Special attention is given to the rock surface temperature, since its accurate determination is required to predict spallation rates under field-drilling conditions.


1991 ◽  
Author(s):  
Edward J. Johnson, Jr. ◽  
Paul V. Hyer ◽  
Paul W. Culotta ◽  
Ivan O. Clark

Author(s):  
Ming-gao Tan ◽  
Hou-lin Liu ◽  
Shou-qi Yuan ◽  
Yong Wang ◽  
Kai Wang

The present deficiency about numerical simulation research on blade outlet width of centrifugal pumps is pointed out. In the case of different outlet widths, the flow field in six centrifugal pumps whose specific speed vary from 45 to 260 are simulated by using commercial code FLUENT and the characteristics are predicted. The standard k-ε turbulence model and SIMPLEC algorithm are chosen in FLUENT. The simulation is steady and moving reference frame is used to consider rotor-stator interaction. The research results show that the change of impeller outlet width has obvious impacts on characteristics at design point, flow field and the shape of performance curves. At nominal condition, the change of outlet width has more important effects on moderate specific speed centrifugal pumps. The flow field analysis indicates that blade outlet width change has an important effect on the location and area of low pressure region behind the blade inlet, jet-wake structure in impellers, the secondary flow in volute cross section and the back flow in impellers. The head-flow curve becomes more flat with the increase of outlet width. For moderate and low specific speed centrifugal pumps, the high efficiency area of efficiency-flow curve get bigger with the increase of outlet width and the area will be constant within certain outlet width change scope for high specific speed centrifugal pump. The research results agree well with experiment results.


2018 ◽  
Vol 38 ◽  
pp. 02022
Author(s):  
Dewei Zhang ◽  
Chuansheng Wang ◽  
Bo Shen ◽  
Shaoming Li ◽  
Huiguang Bian

In recent years, rubber composites reinforced by short fibers has been researched deeply, because of its good performances such as higher wear resistance, higher cut resistance and so on. Some research results indicated that if short fibers get orientation in rubber composites, the performances of rubber products could be promoted greatly. But how to make short fibers get orientation in rubber matrix during extrusion is still a real problem. And there are many parameters affect the short fibers orientation. So, in this paper, the effects of die structure including expansion-die and dam-expansion-die on extrusion flow field of short fiber and rubber composite material during extrusion process has been researched by Polyflow. And the FEA results about the pressure field, velocity field and the velocity vector of the rubber composites flow field indicate that, comparing with expansion-die and the dam-expansion-die, the latter one is better for the extrusion process of rubber composites and making short fibers get radial orientation in rubber matrix.


2013 ◽  
Vol 479-480 ◽  
pp. 401-405
Author(s):  
Hung Cheng Yen ◽  
Wen Syang Hsu ◽  
Yung Jen Cheng ◽  
Sheam Chyun Lin ◽  
Yu Chuan Wu

This study analyzes the flow flied and the guide vane associated with an in-line fan by an integrated numerical and experimental investigation. At first, the flow field associated with the fan is simulated by using a commercial CFD code Fluent with the finite volume method. In addition, the guiding vane profile is imposed and modified by examining characteristics of flow field. An appropriate guiding vane with high-performance and low-noise feature can be achieved after several design iterations. To manufacture the mock-up for experimental verification, the designed fan is expressed in the CAD/CAM format for the rapid-prototype technique. Moreover, a set of relations correlating the performance and noise of this fan prototype are executed with the aids of AMCA test chamber and semi-anechoic chamber, respectively. Consequently, the feasibility of design scheme and numerical system can be verified according to these experimental results. In summary, this work provides a systematic scheme for designing and analyzing the in-line fan.


2013 ◽  
Vol 385-386 ◽  
pp. 93-96
Author(s):  
Hong Ji ◽  
Wei Guo Zhu ◽  
Song Chen ◽  
Jing Zhao

The hydraulic cone valve is an important basic component in Fluid drive and control technology. Characteristic of cone valve inner flow filed influences directly the valves performance. Especially when fluid flow in runner is turbulent, characteristics of flow field have great influence on the valves working performance.Main work of this paper is numerical calculation and simulation of cone valve inner runner flow field inside hydraulic hammer. First make a 3D modeling for cone valve using Pro/E, by fluent this paper analyses and discusses the distribution of hydraulic cone valve internal flow field including flow velocity field, pressure field and flow, etc when the cone valve core taper angle is 30°, the gap is 0.5 mm, and inlet velocity is different, analyses position and strength of the vortex, and finds out the main reason for energy consumption.The results of the study show that by the optimal design of the cone valve seat, the density degree of the flow and the size of the vortex is reduced, the energy loss is reduced, negative pressure zone also changes, the noise is reduced and the energy utilization is improved.


Author(s):  
M. Cao ◽  
K. W. Wang ◽  
L. DeVries ◽  
Y. Fujii ◽  
W. E. Tobler ◽  
...  

A conventional automatic transmission (AT) hydraulic control system includes many spool-type valves that have highly asymmetric flow geometry. An accurate analysis of their flow fields typically requires a time-consuming computational fluid dynamics (CFD) technique. A simplified flow field model that is based on a lumped geometry is computationally efficient. However, it often fails to account for asymmetric flow characteristics, leading to an inaccurate analysis. In this work, a new hydraulic valve fluid field model is developed based on a non-dimensional neural network (NDANN) to provide an accurate and numerically efficient tool in AT control system design applications. A “grow-and-trim” procedure is proposed to identify critical non-dimensional inputs and optimize the network architecture. A hydraulic valve testing bench is designed and built to provide data for neural network model development. NDANN-based fluid force and flow rate estimator are established based on the experimental data. The NDANN models provide more accurate predictions of flow force and flow rates under broad operating conditions compared with conventional lumped flow field models. The NDANN fluid field estimator also exhibits input-output scalability. This capability allows the NDANN model to estimate the fluid force and flow rate even when the design geometry parameters are outside the range of the training data.


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