Speed Reduction Mechanisms of Transverse Lines

2000 ◽  
Vol 2 (4) ◽  
pp. 297-312 ◽  
Author(s):  
Stuart T. Godley ◽  
Thomas J. Triggs ◽  
Brian N. Fildes
Keyword(s):  
Speed Reduction ◽  
Reduction Mechanisms

Structural Stress Analysis and Reliability Evaluation for a New Speed Reducer

2016 ◽  
Vol 33 (5) ◽  
pp. 631-640 ◽  
Author(s):  
Y.-T. Tsai ◽  
K.-H. Lin
Keyword(s):  
Stress Analysis ◽  
High Speed ◽  
Reliability Evaluation ◽  
Speed Reduction ◽  
Performance Requirements ◽  
Reduction Mechanisms ◽  
Speed Reducer ◽  
Structural Stresses ◽  
Bending Fracture ◽  
Design Stress

AbstractReducers are extensively used in many machines for reducing the speeds of mechanism. This paper proposed a new design of speed reducers to meet the performance requirements in high rigidness and large speed-reduction ratios. The movements of the reducer are designed based on the principles of differential displacements of the deceleration gear rings. The geometric models of the related components were designed using CAD software. The motions of mechanism were simulated for identifying the feasibility of designing including acquiring the kinematic properties. The mathematical models of structural stresses analysis were proposed so that the bending and contact stresses of the gear rings could be evaluated, accordingly. Finite element methods (FEM) were also used to analyze the structural stresses of the reducer. The studied results showed that the bending fracture of the gear rings would prior to its contacting fracture. The allowable loading of the reducer was then established according to the analyzed results of the maximum stresses on various transmitted torques. The methods of reliability evaluation were reported for considering the strength variation and calculating the reliabilities of the reducer at various loadings. The studied results are useful in structural design, stress analysis and reliability evaluation for developing high speed-reduction mechanisms.

Quantification of the impact of traffic incidents on speed reduction: A causal inference based approach

2021 ◽  
Vol 157 ◽  
pp. 106163
Author(s):  
Danni Cao ◽  
Jianjun Wu ◽  
Xianlei Dong ◽  
Huijun Sun ◽  
Xiaobo Qu ◽  
...  
Keyword(s):  
Causal Inference ◽  
Traffic Incidents ◽  
Speed Reduction ◽  
The Impact

Numerical study on the airfoil self-noise of three owl-based wings with the trailing-edge serrations

2021 ◽  
pp. 095441002098822
Author(s):  
Dian Li ◽  
Xiaomin Liu ◽  
Lei Wang ◽  
Fujia Hu ◽  
Guang Xi
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Numerical Study ◽  
Barn Owl ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
Trailing Edge ◽  
Reduction Mechanisms ◽  
Trailing Edge Serrations ◽  
Bionic Airfoil

Previous publications have summarized that three special morphological structures of owl wing could reduce aerodynamic noise under low Reynolds number flows effectively. However, the coupling noise-reduction mechanism of bionic airfoil with trailing-edge serrations is poorly understood. Furthermore, while the bionic airfoil extracted from natural owl wing shows remarkable noise-reduction characteristics, the shape of the owl-based airfoils reconstructed by different researchers has some differences, which leads to diversity in the potential noise-reduction mechanisms. In this article, three kinds of owl-based airfoils with trailing-edge serrations are investigated to reveal the potential noise-reduction mechanisms, and a clean airfoil based on barn owl is utilized as a reference to make a comparison. The instantaneous flow field and sound field around the three-dimensional serrated airfoils are simulated by using incompressible large eddy simulation coupled with the FW-H equation. The results of unsteady flow field show that the flow field of Owl B exhibits stronger and wider-scale turbulent velocity fluctuation than that of other airfoils, which may be the potential reason for the greater noise generation of Owl B. The scale and magnitude of alternating mean convective velocity distribution dominates the noise-reduction effect of trailing-edge serrations. The noise-reduction characteristic of Owl C outperforms that of Barn owl, which suggests that the trailing-edge serrations can suppress vortex shedding noise of flow field effectively. The trailing-edge serrations mainly suppress the low-frequency noise of the airfoil. The trailing-edge serration can suppress turbulent noise by weakening pressure fluctuation.

Investigation of planing craft maneuverability using full-scale tests

2021 ◽  
pp. 147509022110303
Author(s):  
Kazem Sadati ◽  
Hamid Zeraatgar ◽  
Aliasghar Moghaddas
Keyword(s):  
Full Scale ◽  
Performance Characteristics ◽  
Forward Speed ◽  
Speed Reduction ◽  
Planing Craft ◽  
Full Scale Tests ◽  
Turning Maneuver

Maneuverability of planing craft is a complicated hydrodynamic subject that needs more studies to comprehend its characteristics. Planing craft drivers follow a common practice for maneuver of the craft that is fundamentally different from ship’s standards. In situ full-scale tests are normally necessary to understand the maneuverability characteristics of planing craft. In this paper, a study has been conducted to illustrate maneuverability characteristics of planing craft by full-scale tests. Accelerating and turning maneuver tests are conducted on two cases at different forward speeds and rudder angles. In each test, dynamic trim, trajectory, speed, roll of the craft are recorded. The tests are performed in planing mode, semi-planing mode, and transition between planing mode to semi-planing mode to study the effects of the craft forward speed and consequently running attitude on the maneuverability. Analysis of the data reveals that the Steady Turning Diameter (STD) of the planing craft may be as large as 40 L, while it rarely goes beyond 5 L for ships. Results also show that a turning maneuver starting at planing mode might end in semi-planing mode. This transition can remarkably improve the performance characteristics of the planing craft’s maneuverability. Therefore, an alternative practice is proposed instead of the classic turning maneuver. In this practice, the craft traveling in the planing mode is transitioned to the semi-planing mode by forward speed reduction first, and then the turning maneuver is executed.

scholarly journals Airflow Characteristics According to the Change in the Height and Porous Rate of Building Roofs for Efficient Installation of Small Wind Power Generators

2021 ◽  
Vol 13 (10) ◽  
pp. 5688
Author(s):  
Jangyoul You ◽  
Kipyo You ◽  
Minwoo Park ◽  
Changhee Lee
Keyword(s):  
Wind Speed ◽  
Wind Power ◽  
Turbulence Intensity ◽  
Flow Characteristics ◽  
High Porosity ◽  
Power Generators ◽  
Speed Reduction ◽  
Reduction Effect ◽  
Wind Power Generators ◽  
The Impact

In this paper, the air flow characteristics and the impact of wind power generators were analyzed according to the porosity and height of the parapet installed in the rooftop layer. The wind speed at the top was decreasing as the parapet was installed. However, the wind speed reduction effect was decreasing as the porosity rate increased. In addition, the increase in porosity significantly reduced turbulence intensity and reduced it by up to 40% compared to no railing. In the case of parapets with sufficient porosity, the effect of reducing turbulence intensity was also increased as the height increased. Therefore, it was confirmed that sufficient parapet height and high porosity reduce the effect of reducing wind speed by parapets and significantly reducing the turbulence intensity, which can provide homogeneous wind speed during installation of wind power generators.

Lithium Sulfur Battery: Oxidation/Reduction Mechanisms of Polysulfides in THF Solutions

1988 ◽  
Vol 135 (5) ◽  
pp. 1045-1048 ◽  
Author(s):  
H. Yamin ◽  
A. Gorenshtein ◽  
J. Penciner ◽  
Y. Sternberg ◽  
E. Peled
Keyword(s):  
Lithium Sulfur Battery ◽  
Oxidation Reduction ◽  
Reduction Mechanisms ◽  
Sulfur Battery ◽  
Lithium Sulfur

Vibration and Stability Behaviour of Sandwiched Viscoelastic Pipes Conveying a Non-Newtonian Fluid

2010 ◽  
Author(s):  
Vincent O. S. Olunloyo ◽  
Charles A. Osheku ◽  
Sidikat I. Kuye
Keyword(s):  
Newtonian Fluid ◽  
Fluid Velocity ◽  
Linear Equations ◽  
Steel Pipes ◽  
Flow Parameters ◽  
Internal Fluid ◽  
Reduction Mechanisms ◽  
Internal Fluid Flow ◽  
Flow Induced Vibrations ◽  
Flow Variables

Internal fluid flow parameters in conjunction with elastomechanical properties of conveyance systems have significantly modulated flow induced vibrations in pipeline and riser systems. Recent advances on the mechanics of sandwich elastic systems as effective vibration and noise reduction mechanisms have simulated the possibility of replacing traditional steel pipes with sandwich pipes in deepwater environment. The dynamic behaviour and stability of sandwich elastic pipes conveying a non-Newtonian fluid are investigated in this paper. For this problem, a set of generalised non-linear equations governing the vibration of sandwich pipes held together in pressurised environment and conveying a non-Newtonian fluid is presented. By linearizing the governing partial differential equation matching the problem physics, under slight perturbation of the internal fluid velocity and other flow variables closed form analytical results for the system dual natural frequencies and stability under external excitation are computed for field designs and applications. Results show that for a given length of pipe, beyond the critical velocity, instability increases with the velocity of conveyance.

Reduction Mechanisms in Manganese Ore Reduction

2015 ◽  
Vol 46 (6) ◽  
pp. 2534-2552 ◽  
Author(s):  
Theresa Coetsee ◽  
Christian Reinke ◽  
Johannes Nell ◽  
Petrus Christiaan Pistorius
Keyword(s):  
Manganese Ore ◽  
Ore Reduction ◽  
Reduction Mechanisms
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