scholarly journals Comparison between Laser and Stamping without Die (SWD) for Micro Tapered Hole Forming

2016 ◽  
Vol 6 (3) ◽  
pp. 77 ◽  
Author(s):  
Yung-Chou Hung ◽  
Yuan-Jen Chang ◽  
Chia-Lung Kuo ◽  
Jin-Chen Hsu ◽  
Chao-Ching Ho
Keyword(s):  
Tapered Hole

scholarly journals Numerical Investigation on Static and Rotor-Dynamic Characteristics of Convergent-Tapered and Divergent-Tapered Hole-Pattern Gas Damper Seals

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2324
Author(s):  
Dan Sun ◽  
Sheng-Yuan Li ◽  
Huan Zhao ◽  
Cheng-Wei Fei
Keyword(s):  
Dynamic Characteristics ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Rotor System ◽  
Damping Coefficient ◽  
Single Frequency ◽  
Relative Variation ◽  
Gas Damper ◽  
Rotor Dynamic ◽  
Tapered Hole

To study the influence of taper seal clearance on the static and rotor-dynamic characteristics of hole-pattern damper seals, this paper develops three-dimensional transient computational fluid dynamic methods, which comprise single-frequency and multi-frequency elliptical orbit whirl model, by the transient solution combined with a mesh deformation technique. Through the investigations, it is illustrated that: (1) In the present paper, the leakage rates of convergent-tapered hole-pattern damper seals are less than divergent-tapered hole-pattern damper seals for the same average seal clearance, and the maximum relative variation reaches 16%; (2) Compared with a constant clearance hole-pattern damper seal, the maximum relative variation of the rotor-dynamic coefficients is 1,865% for nine taper degrees in this paper; (3) Convergent-tapered hole-pattern damper seals have smaller reaction forces and effective damping coefficient, larger cross-over frequency, and direct stiffness coefficient, while divergent-tapered damper seals have the opposite effects; (4) Divergent-tapered hole-pattern damper seals alleviate the rotor whirl because of a larger effective damping coefficient when the rotor system has large natural frequency and small eccentricity. Convergent-tapered damper seals provide both sealing and journal bearing capabilities at the same time, and are more advantageous to the stability of the rotor system when rotor eccentricity is the main cause of rotor instability.

Temperature and refractive index-independent mode converter based on tapered hole-assisted dual-core fiber

2021 ◽  
pp. 1-1
Author(s):  
Jiaming Zhang ◽  
Chunying Guan ◽  
Yuan Jin ◽  
Peng Pe ◽  
Tailei Cheng ◽  
...  
Keyword(s):  
Refractive Index ◽  
Mode Converter ◽  
Core Fiber ◽  
Dual Core ◽  
Independent Mode ◽  
Tapered Hole

scholarly journals Prediction and Verification of Lateral Joining Strength for Tapered-Hole Clinching using the Taguchi Method

2016 ◽  
Vol 25 (1) ◽  
pp. 36-42
Author(s):  
D.S. Kang ◽  
E.T. Park ◽  
A. Tullu ◽  
B.S. Kang ◽  
W.J. Song
Keyword(s):  
Taguchi Method ◽  
Joining Strength ◽  
Tapered Hole

Numerical study of the acoustic properties of micro-perforated panels with tapered hole

2014 ◽  
Vol 62 (3) ◽  
pp. 152-159 ◽  
Author(s):  
Y.J. Qian ◽  
K. Cui ◽  
S.M. Liu ◽  
Z.B. Li ◽  
D.Y. Kong ◽  
...  
Keyword(s):  
Numerical Study ◽  
Acoustic Properties ◽  
Tapered Hole

Optical investigations of nozzle geometrical and dynamic factors on formation and development characteristics of string cavitation with large-scale diesel tapered-hole nozzles

2020 ◽  
pp. 146808742096933
Author(s):  
Wei Guan ◽  
Zhixia He ◽  
Lian Duan ◽  
Tianyi Cao ◽  
Shenxing Sun ◽  
...  
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Physical Phenomenon ◽  
Distribution Characteristics ◽  
High Speed Imaging ◽  
Cavitation Inception ◽  
Dynamic Factors ◽  
Structure Changes ◽  
Primary Breakup ◽  
Tapered Hole

Cavitation is known to be an essential physical phenomenon to induce the fuel primary breakup process, which further influences subsequent secondary atomization and combustion in diesel engines. Different from normal geometry-induced cavitation, the special vortex-induced cavitation, which may influence strongly spray characteristics, is seldom investigated comparatively. In this paper, formations and developments of string cavitation are captured in scaled-up transparent replicas of diesel tapered-hole nozzles by high-speed imaging technology. The ensemble average images were post-processed by MATLAB code for characterizing the string cavitation at fixed needle lifts. The results indicate that string cavitation tends to occur initially in the middle of the nozzle holes. Besides, shedding bubbles from geometry-induced cavitation may stimulate the string cavitation inception as an inducing factor. The morphology and duration of both two types of string cavitation are largely influenced by needle lifts and cavitation number. Moreover, it is concluded that string cavitation hardly occurs in nozzles with low hole entrance location, and the hole entrance rounding structure changes the distribution characteristics of string cavitation. Finally, it is ascertained that the variation of magnification ratio changes little or nothing about development and distribution characteristics of string cavitation.

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