Double Helical Synchronous Belt Transmission Design

2014 ◽  
Vol 800-801 ◽  
pp. 672-677
Author(s):  
Jian Hua Guo ◽  
Hong Yuan Jiang ◽  
Yi Zhen Wu ◽  
Wen Ya Chu ◽  
Qing Xin Meng
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Three Dimensional ◽  
Transmission Error ◽  
Transmission Model ◽  
Adjacent Area ◽  
Speed Test ◽  
Finite Element Software ◽  
Timing Belt ◽  
Belt Transmission

The meshing impact noise caused by the gradually engagement between double helical synchronous belt and the pulley was reduced due to its spiral angle effect. Therefore, double helical synchronous belt transmission receives much concern with its excellent characteristics of de-noising, low transmission error and high carrying capacity. The profiles of synchronous belt and belt pulley were studied based on conjugate-curvature high degree contact meshing theory under the circumstance that the pitch of belt and belt pulley are identical. The higher contact strength of the belt teeth and a smaller clearance in the contact point adjacent area were ensured with Hertz contact theory as the synchronous belt is in contact with pulley. And then a conjugated arc tooth profile with two-step contact and three-step adjacent gap infinitesimal was proposed based on the simple easy to processing method, which was adopted as main parameters for double synchronous belt and pulley’s normal teeth profile. The three-dimensional transmission model was built and the static nonlinear contact analysis was done with finite element software ANSYS. Finally, the noise experiment was conducted on the high speed test bench to compare the noise reduction effect between double helical synchronous belt and straight tooth timing belt with the identical end face profile. The simulation and experiment result show that the double helical synchronous belt transmission can reduce noise level by 11dB approximately compared with straight tooth timing belt transmission.

scholarly journals Mathematical and Finite Element Modeling of Micro-Modification for Marine Gear

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Xiongxi Wu ◽  
Qifeng Gao ◽  
Zesong Li
Keyword(s):  
Finite Element ◽  
Optimization Design ◽  
Impact Load ◽  
Equivalent Stress ◽  
High Strength ◽  
Transmission Error ◽  
Gear Transmission ◽  
Transmission Model ◽  
Finite Element Software ◽  
Before And After

Based on the computer simulation technique, this paper used the professional gear design software MASTA and finite element software ANSYS combined with the method of gear micro-modification to redesign the gear profile and eventually realized the optimization design of gear micro-modification. Then the gear transmission model of one-level reducer was established to simulate and analyze the contact equivalent stress, transmission error, and meshing impact before and after gear modification. By comparing the simulations results it is found that gear micro-modification can lower meshing impact load, reduce the vibration strength, make gear transmission steady, and improve the gear bearing capacity. By comparing the transmission error curves and meshing impact load curves before and after gear micro-modification, this helps to understand the effects of gear micro-modification on the gear transmission and provides basis references for the future redesign of the marine gears with high strength and long service life.

Three-Dimensional Two-Phase Flow Simulations of Water Braking Phenomena for High-Speed Test Track Sled

2021 ◽  
Author(s):  
Jose Terrazas ◽  
Arturo Rodriguez ◽  
Vinod Kumar ◽  
Richard Adansi ◽  
V. M. Krushnarao Kotteda
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Initial Boundary ◽  
Phase Flow ◽  
Momentum Exchange ◽  
Two Phase ◽  
Test Track ◽  
Speed Test ◽  
Liquid Phases ◽  
Multi Phase Flow

Abstract Specializing in high-speed testing, Holloman High-Speed Test Track (HHSTT) uses a process called ‘water braking’ as a method to bring vehicles at the test track to a stop. This method takes advantage of the higher density of water, compared to air, to increase braking capability through momentum exchange. By studying water braking using Computational Fluid Dynamics (CFD), forces acting on track vehicles can be approximated and prepared for prior to actual test. In this study, focus will be made on the brake component of the track sled that is responsible for interacting with the water for braking. By discretizing a volume space around our brake, we accelerate water and air to relatively simulate the brake engaging. The model is a multi-phase flow that uses the governing equations of gas and liquid phases with the finite volume method, to perform 3D simulations. By adjusting the inflow velocity of air and water, it is possible to simulate HHSTT sled tests at various operational speeds. In the development of the 3D predictive model, convergence issues associated with the numerical mesh, initial/boundary conditions, and compressibility of the fluids were encountered. Once resolved, the effect of inflow velocities of water and air on the braking of the sled are studied.

A Numerical Investigation of the Influence of the Blade–Vortex Interaction on the Dynamic Stall Onset

2021 ◽  
Author(s):  
Camille Castells ◽  
François Richez ◽  
Michel Costes
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Dynamic Stall ◽  
Test Case ◽  
Vortex Interaction ◽  
Fluid Structure ◽  
Speed Test ◽  
Vortex Model ◽  
Flow Parameters ◽  
Blade Vortex Interaction

Recently, fluid–structure coupling simulations of helicopter rotors in high-thrust forward flight suggested that dynamic stall might be triggered by the blade–vortex interaction. However, no clear evidence of a correlation between dynamic stall and blade–vortex interaction has yet been given. We propose in this paper a simplified two-dimensional numerical model that can be used to indicate the role that the blade–vortex interaction plays in dynamic stall onset for different flight conditions. In this model, the rotor blade element is considered in pitching oscillation motion with a nonuniform translation, and a simplified vortex model can be introduced or not in the simulation to highlight the effect of blade–vortex interaction. All flow parameters of this simplified model are deduced from data provided by previous three-dimensional high-fidelity fluid–structure simulations. The method is used for validation and analysis of three flight conditions. The results show that, for the two cases with moderate advance ratio, the dynamic stall event is only triggered when a blade–vortex interaction occurs in the stall region. For the high-speed test case, the dynamic stall event seems to be only triggered by the very high angle of attack due to the motion of the blade.

scholarly journals Determining the Power Consumption of the Automatic Device for Belt Perforation Based on the Dynamic Model

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 317
Author(s):  
Dominik Wojtkowiak ◽  
Krzysztof Talaśka ◽  
Dominik Wilczyński ◽  
Jan Górecki ◽  
Krzysztof Wałęsa
Keyword(s):  
High Speed ◽  
Equations Of Motion ◽  
Automatic Device ◽  
Drive System ◽  
Correct Operation ◽  
Timing Belt ◽  
Two Stages ◽  
Belt Transmission ◽  
Linear Drive System ◽  
Selection Of

The subject of the dynamic analysis presented in the article is the linear drive system with a timing belt utilized in the automatic device for polymer composite belt perforation. The analysis was carried out in two stages. In the first stage, the timing belt was modeled with all the relevant dynamic phenomena; subsequently, the tension force of the belt required for the correct operation of the belt transmission was determined. The necessary parameters for belt elasticity, vibration damping, and inertia are based exclusively on the catalog data provided by the manufacturer. During the second stage, equations of motion were derived for the designed drive system with a timing belt, and characteristics were identified to facilitate the optimal selection of electromechanical drives for the construction solution under analysis. The presented methodology allows for designing an effective solution that may be adapted for other constructions. The obtained results showed the influence of the kinematic parameters on the motor torque and proved the importance of reducing the mass of the components in machines that perform high-speed processes.

scholarly journals Settlement simulation of soft clay in the subway under dynamic load based on Midas GTS NX

2021 ◽  
Vol 237 ◽  
pp. 03011
Author(s):  
Quan Cao ◽  
Yu Hang
Keyword(s):  
Finite Element ◽  
Dynamic Load ◽  
High Speed ◽  
Large Population ◽  
Soft Clay ◽  
Three Dimensional ◽  
Element Model ◽  
Structural Safety ◽  
Finite Element Software ◽  
Saturated Soft Clay

The subway has become the main way for people to travel nowadays. The saturated soft clay area has a large population and subway construction is the most extensively distributed. The saturated soft clay foundation will settle under the dynamic load of the subway train, which will affect the service life and structural safety. To study the settlement characteristics of soft clay under the dynamic load of the subway, a three-dimensional dynamic finite element model was established based on the finite element software Midas GTS NX, and the soft clay under the normal design speed (80 km/h) and the high-speed (120 km/h) were compared and analyzed. The research results show that the higher the train speed, the larger the lateral influence range of the surface settlement trough, but the settlement decreases with the increase of the subway running speed. The settlement of the subway line after one year of operation is about 45mm, and the settlement after 20 years is about 58mm. The growth rate of the settlement prediction curve decreases gradually, and the settlement increment is very small for a long time in the later period of operation.

scholarly journals Shrink-fitted joint behavior using three-dimensional solid finite elements in rotor dynamics with inclusion of stress-stiffening effect

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878005 ◽  
Author(s):  
Eerik Sikanen ◽  
Janne E Heikkinen ◽  
Jussi Sopanen
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Three Dimensional ◽  
Campbell Diagram ◽  
Finite Element Software ◽  
Element Approach ◽  
Solid Finite Elements ◽  
Rotor Assembly ◽  
Stiffening Effect ◽  
Good Agreement

In this article, the contact behavior of a shrink-fitted joint in a rotor assembly at different spin speeds is studied, using the three-dimensional solid finite element approach. A custom frictionless contact model is proposed and extensively tested by means of simulation. The theory for solving pre-stressed damped eigenvalue problem is presented and implemented, and the results are presented in Campbell diagram form. Two sample rotor assemblies are studied. In addition, experimental modal analysis results of a shrink-fitted joint with various interferences are presented and numerically studied. The reduction of the interference of the shrink-fitted joint due to centrifugal forces at high-speed operation as well as the contact status are updated at each rotational speed step. The inclusion of stress-stiffening effect is studied in detail. The comparison of the Campbell diagram results with the results obtained using a commercial finite element software (Ansys) shows a good agreement.

Effect of Loading Level and Distribution on LPT Losses

2008 ◽  
Author(s):  
C. Prakash ◽  
D. G. Cherry ◽  
H. W. Shin ◽  
J. Machnaim ◽  
L. Dailey ◽  
...  
Keyword(s):  
Reynolds Number ◽  
High Speed ◽  
Three Dimensional ◽  
Suction Side ◽  
Speed Test ◽  
Loading Level ◽  
Static Pressure Distribution ◽  
Turbulence Transition ◽  
Primary Focus ◽  
Exit Mach Number

This paper reports the results of an experimental and analytical study dealing with the effect of loading level and distribution on low-pressure turbine (LPT) blade performance. Only a single blade row is considered here, and the study is conducted in a stationary linear cascade that simulates the aero characteristics of a modern LPT design. The loading level and distribution are systematically varied by changing the number of blades (solidity), the stagger angle, and the unguided turning angle. The exit Mach number for this high-speed test is set at 0.64. The Zweifel number ranges from ∼ 1 (nominal lift) to ∼ 1.27 (high lift). The Reynolds number (based on chord and exit velocity) is varied from ∼70,000 to ∼350,000, a range that is broad enough to cover typical cruise and take-off conditions. While some data is taken near the end-walls, the primary focus of this study is on measurements at the mid-span. In addition to the profile loss, measurements include static pressure distribution on the blade surface (loading) and flow visualization. Data demonstrates increased suction side separation and consequent high losses as the loading level increases, the loading is moved aft, or the Reynolds number decreases. Three-dimensional CFD simulations, in conjunction with a turbulence transition model, corroborate these findings.

scholarly journals Three-dimensional contact point determination and contour reconstruction during active whisking behavior of the awake rat

2020 ◽  
Author(s):  
Lucie A. Huet ◽  
Hannah M. Emnett ◽  
Mitra J. Z. Hartmann
Keyword(s):  
High Speed ◽  
Contact Point ◽  
Three Dimensional ◽  
Contact Points ◽  
Unique Mapping ◽  
Contour Reconstruction ◽  
Awake Rat ◽  
Exact Shape ◽  
Point Determination ◽  
Open Question

AbstractThe rodent vibrissal (whisker) system has been studied for decades as a model of active touch sensing. There are no sensors along the length of a whisker; all sensing occurs at the whisker base. Therefore, a large open question in many neuroscience studies is how an animal could estimate the three-dimensional location at which a whisker makes contact with an object. In the present work we simulated the exact shape of a real rat whisker to demonstrate the existence of a unique mapping from triplets of mechanical signals at the whisker base to the three-dimensional whisker-object contact point. We then used high speed video to record whisker deflections as an awake rat whisked against a peg and used the mechanics resulting from those deflections to extract the contact points along the peg surface. A video shows the contour of the peg gradually emerging during active whisking behavior.

High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

1994 ◽  
Vol 52 ◽  
pp. 218-219
Author(s):  
Robert W. Mackin
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Image Data ◽  
Ccd Camera ◽  
Objective Lens ◽  
Array Processor ◽  
Vaginal Smears ◽  
Low Contrast ◽  
Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

Effects of Three-Dimensional Pressure Gradients on High-Speed Turbulent Boundary Layers

2021 ◽  
Author(s):  
Scott J. Peltier ◽  
Brian E. Rice ◽  
Ethan Johnson ◽  
Venkateswaran Narayanaswamy ◽  
Marvin E. Sellers
Keyword(s):  
Boundary Layers ◽  
High Speed ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Pressure Gradients
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