scholarly journals Design of internal flow passage of internal chip removal drill for suction-type internal chip removal system

Author(s):  
Meng Wang ◽  
Chengyang Xu ◽  
Aili Zou ◽  
Gongdong Wang ◽  
Yiwen Wang ◽  
...  
Author(s):  
Toru Shigemitsu ◽  
Junichiro Fukutomi ◽  
Ryosuke Sonohata

Small hydropower generation is one of important alternative energy, and potential of small hydropower is great. Efficiency of small hydro turbines is lower than that of large one, and these small hydro turbine’s common problems are out of operation by foreign materials. Then, there are demands for small hydro turbines to keep high performance and wide flow passage. Therefore, we adopted contra-rotating rotors, which can be expected to achieve high performance and enable to use low-solidity rotors with wide flow passage, in order to accomplish high performance and stable operation. Final goal of this study is development of a small hydro turbine like electrical goods, which has high portability and makes an effective use of unused small hydro power energy source. In this research, experimental apparatus of the contra-rotating small hydro turbine with 60mm casing diameter was manufactured and performance of it was investigated by an experiment. Efficiency of the contra-rotating small hydro turbine was high in pico-hydro turbine and high efficiency could be kept in wide flow rate range. Internal flow condition, which was difficult to measure experimentally, was shown by the numerical flow analysis. Further, influence of spokes to support the rotor was clarified. Then, a relation between the performance and internal flow condition was considered by the experimental and numerical analysis results.


2015 ◽  
Vol 18 (5) ◽  
pp. 19-25
Author(s):  
Zhenmu Chen ◽  
Qingsheng Wei ◽  
Patrick Mark Singh ◽  
Young-Do Choi

2020 ◽  
Vol 108 (5-6) ◽  
pp. 1297-1308
Author(s):  
Yajun Liu ◽  
Shipeng Li ◽  
Hao Li ◽  
Xuda Qin ◽  
Youqiang Xing ◽  
...  

1979 ◽  
Vol 46 (1) ◽  
pp. 45-51 ◽  
Author(s):  
M. J. Hannoyer ◽  
M. P. Paidoussis

This paper develops a general theory for the dynamics of slender, nonuniform axisymmetric beams subjected to either internal or external flow, or to both simultaneously. The effect of the boundary layer of the external flow is taken into account in the formulation. Typical solutions of the equations of motion are presented for cantilevered conical beams in external flow and for beams with a conical internal flow passage. Such systems lose stability at sufficiently high flow velocity, internal or external, either by flutter or by buckling. The effect of several parameters is investigated. For internal flow, the internal and external shape, whether uniform or conical, and the density of the surrounding fluid have sometimes unexpected effects on stability; e.g., tubular beams lose stability at lower internal flow when immersed in water than when in air. For external flow the effects of conicity, free end shape and boundary-layer thickness are investigated; the latter has a strong stabilizing influence, such that simple theory neglecting this effect results in serious error.


2013 ◽  
Vol 433-435 ◽  
pp. 1937-1942
Author(s):  
Xin Nie ◽  
Ding Guo Yang

This paper introduces a minor drainage pump used in air-conditioning system. The numerical simulation has been done to analyze the internal flow field and sound pressure level in drainage pump. FlUENT is used in this paper. And LES (Large Eddy Simulation) is taken to catch the pressure fluctuation in this flow passage. CFD results show that pressure fluctuation is the main sound source in the pump.


2016 ◽  
Vol 33 (3) ◽  
Author(s):  
Yexiang Xiao ◽  
Yangyang Yao ◽  
Zhengwei Wang ◽  
jin zhang ◽  
Yongyao Luo ◽  
...  

Purpose Numerically analyzed the flow characteristic and explored the hydrodynamic mechanism of the pump mode hump district formation of a Francis pump-turbine. Design/methodology/approach Numerical simulations were conducted of the entire pump-turbine flow passage under different discharge conditions by adopting the SST-CC turbulence model. The internal flow at hump district has been explained in detail combined with the model test in this paper. The unsteady flow and pressure fluctuation characteristics are analysed under five different discharge conditions in the hump and nearby region. The reason of the hump district formation is explored combined with the flow components hydraulic loss. Findings The large hydraulic loss, high relative peak-to-peak amplitudes and low dominant frequencies are on account of the disorganized internal flow condition. The formation of the hump district is concerned with the large hydraulic loss inside the draft tube, runner and guide vanes as there occurs secondary flow, backflow even vortex in the hump district. In addition, the low dominant frequencies at recording points inside the flow passage are always accompanied with the change of flow patterns and the spreading of the pressure fluctuations. Originality/value The analysis method of each flow components hydraulic loss combined with internal flow structure is adopted to explore the mechanism of pump mode hump characteristic. The flow characteristic and pressure pulse characteristics all correspond to the flow components hydraulic loss.


It is necessary to use an efficient chip removal system to increase productivity on the shop floor. Conventional conveyor systems such as belt conveyors are being used in industries. The Belt conveyors used in the computer numerical control (CNC) machining firms, remove the metal chips falling from the machine. A machine shop is operated on a small scale certainly has limitations to adopt these chip removal systems economically and precisely. In order to simplify the process, decided to develop an efficient and economical solution for the chip removal process. The spring type chip conveyor is designed to overcome the problems faced while using a belt conveyor and also to remove the metal chips from the machine in a faster and cheaper rate.


Author(s):  
Shuhong Liu ◽  
Yujun Sha ◽  
Yulin Wu ◽  
Baogang Wang

The pressure fluctuation in the internal flow passage of centrifugal pump is a key factor affecting the stability of the hydraulic system, especially working at conditions of high temperature and pressure. In this paper, RNG k–ε turbulent model is adopted to simulate the unsteady flow through the whole flow passage of centrifugal pump working at temperature T = 300 °C and high pressure P = 280 bar. The pressure fluctuation is calculated at the predefined reference points in the different planes. By analyzing the results, it is found that: 1) the rotor-stator interaction between impeller and diffuser is the main cause for pressure fluctuation; 2) the dominant frequency of pressure fluctuation in the flow passage of impeller is the diffuser passing frequency; 3) the dominant frequency at the points of casing wall is almost the same, and the maximum amplitude is relatively small.


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