scholarly journals A Comparison Between Theoretical Prediction and Experimental Measurement of the Dynamic Behavior of Spur Gears

1992 ◽  
Author(s):  
Brian Rebbechi ◽  
B. David Forrester ◽  
Fred B. Oswald ◽  
Dennis P. Townsend
Keyword(s):  
Experimental Data ◽  
Computer Model ◽  
High Speed ◽  
Contact Region ◽  
Experimental Results ◽  
Average Error ◽  
Spur Gears ◽  
Gear Noise ◽  
Gear Teeth ◽  
Model Predictions

Abstract A comparison was made between computer model predictions of gear dynamic behaviour and experimental results. The experimental data were derived from the NASA gear noise rig, which was used to record dynamic tooth loads and vibration. The experimental results were compared with predictions from the Australian Defence Science and Technology Organisation Aeronautical Research Laboratory’s gear dynamics code, for a matrix of 28 load-speed points. At high torque the peak dynamic load predictions agree with experimental results with an average error of 5 percent in the speed range 800 to 6000 rpm. Tooth separation (or bounce), which was observed in the experimental data for light-torque, high-speed conditions, was simulated by the computer model. The model was also successful in simulating the degree of load sharing between gear teeth in the multiple-tooth-contact region.

The Compliance of Solid, Wide-Faced Spur Gears

1990 ◽  
Vol 112 (4) ◽  
pp. 590-595 ◽  
Author(s):  
J. H. Steward
Keyword(s):  
Experimental Data ◽  
Contact Line ◽  
Load Distribution ◽  
3D Model ◽  
Spur Gear ◽  
Point Load ◽  
Spur Gears ◽  
Line Load ◽  
Gear Teeth ◽  
Theoretical Results

In this paper, the requirements for an accurate 3D model of the tooth contact-line load distribution in real spur gears are summarized. The theoretical results (obtained by F.E.M.) for the point load compliance of wide-faced spur gear teeth are set out. These values compare well with experimental data obtained from tests on a large spur gear (18 mm module, 18 teeth).

New model of dielectric strength of Debye relaxation in monohydroxy alcohols

2019 ◽  
Vol 33 (26) ◽  
pp. 1950313
Author(s):  
Li-Na Wang ◽  
Xing-Yu Zhao ◽  
Yi-Neng Huang
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
High Temperature ◽  
Ising Model ◽  
Dielectric Spectroscopy ◽  
Dielectric Strength ◽  
Experimental Results ◽  
Debye Relaxation ◽  
New Model ◽  
Model Predictions

The Debye relaxation of dielectric spectroscopy exists extensively in monohydroxy alcohols, and the existing theory of the dielectric strength is obviously inconsistent with the experimental results. In this paper, we propose an Ising model of infinite free-rotating pseudospin chains and get the exact solution of the dielectric strength versus temperature. The model predictions are qualitatively consistent with the experimental results, especially the crossover from the low to the high-temperature Curie–Weiss law. The quantitative comparisons indicate that the model predictions can agree well with the experimental data below 250 K.

scholarly journals Study of Lubricant Jet Flow Phenomena in Spur Gears

1975 ◽  
Vol 97 (2) ◽  
pp. 283-288 ◽  
Author(s):  
L. S. Akin ◽  
J. J. Mross ◽  
D. P. Townsend
Keyword(s):  
Motion Picture ◽  
High Speed ◽  
Drop Size ◽  
Gear Tooth ◽  
Jet Flow ◽  
Spur Gear ◽  
Spur Gears ◽  
Gear Teeth ◽  
Flow Phenomena ◽  
Oil Jet

Lubricant jet flow impingement and penetration depth into a gear tooth space were measured at 4920 and 2560 using a 8.89-cm- (3.5-in.) pitch dia 8 pitch spur gear at oil pressures from 7 × 104 to 41 × 104 N/m2 (10 psi to 60 psi). A high speed motion picture camera was used with xenon and high speed stroboscopic lights to slow down and stop the motion of the oil jet so that the impingement depth could be determined. An analytical model was developed for the vectorial impingement depth and for the impingement depth with tooth space windage effects included. The windage effects on the oil jet were small for oil drop size greater than 0.0076 cm (0.003 in.). The analytical impingement depth compared favorably with experimental results above an oil jet pressure of 7 × 104 N/m2 (10 psi). Some of this oil jet penetrates further into the tooth space after impingement. Much of this post impingement oil is thrown out of the tooth space without further contacting the gear teeth.

Performance Calculation of a TBD234V12 Diesel Engine with STC

2012 ◽  
Vol 157-158 ◽  
pp. 1075-1078
Author(s):  
Yang Wang ◽  
Yin Yan Wang ◽  
Fan Shi ◽  
Xin Guang Li
Keyword(s):  
Experimental Data ◽  
Diesel Engine ◽  
Computer Model ◽  
High Speed ◽  
Marine Diesel Engine ◽  
High Speed Diesel ◽  
Turbocharging System ◽  
Marine Diesel ◽  
Performance Calculation ◽  
Good Agreement

A computer model for a TBD234V12 marine high-speed diesel engine with 2 turbocharger(2TC) is built on GT-POWER. For validating the computer model, a calculation to the conventional turbocharging system has been done firstly, and the results show good agreement with experimental data. The computer model has then been used for predictive studies of the diesel engine with the proposed STC system on the mapping characteristics. From these results, it can be seen that the STC system can not only improve the part load performance of the diesel engine obviously, but also enlarge the operating range of the marine diesel engine.

High Speed Milling Vibration Surveillance with Optimal Spindle Speed Based on Optimal Speeds Map

2013 ◽  
Vol 597 ◽  
pp. 125-130 ◽  
Author(s):  
Krzysztof J. Kalinski ◽  
Marek A. Galewski ◽  
Michał R. Mazur
Keyword(s):  
Experimental Data ◽  
Computational Model ◽  
High Speed ◽  
End Milling ◽  
The Self ◽  
Experimental Results ◽  
Modal Parameters ◽  
Chatter Vibration ◽  
High Speed Milling ◽  
Milling Vibration

The paper presents the method of the surveillance of the self-excited chatter vibration. At first, the workpiece modal parameters are estimated based on experimental data which leads to verification of computational model. Then, for selected surface points optimal spindle speeds are calculated. By considering sufficient amount of points it is possible to build a map of optimal spindle speeds. Experimental results show that this map may be used effectively for eliminating chatter in case of the process of ball end milling of a curved flexible detail.

Smeared-Property Models for Shock-Impact Reliability of Area-Array Packages

2007 ◽  
Vol 129 (4) ◽  
pp. 373-381 ◽  
Author(s):  
Pradeep Lall ◽  
Dhananjay Panchagade ◽  
Yueli Liu ◽  
Wayne Johnson ◽  
Jeff Suhling
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Printed Circuit Boards ◽  
Ball Grid Array ◽  
Drop Impact ◽  
Transient Dynamics ◽  
Valuable Insight ◽  
Cost Constraints ◽  
Plastic Ball ◽  
Model Predictions

Portable electronics is subjected to extreme accelerations in shock and drop impact. Product development cycle times and the cost constraints often restrict the number of design variations tested for drop robustness prior to identification of the final configuration. Simulation models capable of predicting transient dynamics can provide valuable insight into the design reliability under shock environments. In this study, explicit finite-element models have been used to study the transient dynamics of printed circuit boards during drop from 6ft. Methodologies for modeling components using smeared-property formulations have been investigated. Reduced integration element formulations examined include shell and solid elements. Model predictions have been validated with experimental data. Results show that models with smeared properties can predict transient-dynamic response of board assemblies in drop impact fairly accurately. High-speed data acquisition system has been used to capture in situ strain, continuity, and acceleration data in excess of 1×106samples∕s. Ultra-high-speed video at 40,000fps has been used to capture the deformation kinematics. Component types examined include plastic ball-grid arrays, tape-array ball-grid array, quad-flat-no-lead package, and conduction-cooled ball-grid array. Model predictions have been correlated with experimental data. Impact of experimental error sources on model correlation with experiments has been also investigated

Models for Reliability of Fine-Pitch BGAs and CSPs in Shock and Drop Impact

2004 ◽  
Author(s):  
Pradeep Lall ◽  
Dhananjay Panchagade ◽  
Yueli Liu ◽  
Wayne Johnson ◽  
Jeff Suhling
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Printed Circuit Boards ◽  
Drop Impact ◽  
Explicit Finite Element ◽  
Ball Grid Arrays ◽  
Fine Pitch ◽  
Plastic Ball ◽  
Model Predictions ◽  
High Speed Data Acquisition

Drop-induced failures are most dominant in portable electronic products. In this study, explicit finite element models have been used to study the transient dynamics of printed circuit boards during drop from 6 ft. Methodologies for modeling components using smeared property formulations have been investigated. Reduced integration element formulations examined include – shell and solid elements. Model predictions have been validated with experimental data. Results show that models with smeared properties can predict transient-dynamic response of board assemblies in drop-impact, fairly accurately. High-speed data acquisition system has been used to capture in-situ strain, continuity and acceleration data in excess of 1 million samples per second. Ultra high-speed video at 40,000 fps per second has been used to capture the deformation kinematics. Component types examined include – plastic ball-grid arrays, tape-array BGA, QFN, and C2BGA. Model predictions have been correlated with experimental data. Impact of experimental error sources on model correlation with experiments also has been investigated.

On the Dynamic Gear Tooth Loading as Affected by Bearing Clearances in High Speed Machinery

1982 ◽  
Vol 104 (4) ◽  
pp. 724-730 ◽  
Author(s):  
B. M. Bahgat ◽  
M. O. M. Osman ◽  
T. S. Sankar
Keyword(s):  
High Speed ◽  
Design Method ◽  
Gear Tooth ◽  
Contact Point ◽  
Velocity Ratio ◽  
Spur Gears ◽  
Governing Equations ◽  
Contact Mode ◽  
Gear Teeth ◽  
Geometrical Constraints

The paper studies the effect of bearing clearances in the dynamic analysis of gear mechanisms in high speed machinery. For this purpose, an analytical model is developed based on the interdependence between kinematics and kinetic relationships that must be satisfied when contact is maintained between the journal and its bearing. The contact modes are formulated such that the bearing eccentricity vector must align itself with bearing normal force at the point of contact. The analysis mainly relies on determining the direction of the bearing eccentricity vector defined as the clearance angles βi at the bearing revolutes for each contact mode of the gear teeth. The governing equations of the clearance angles are developed using the geometrical constraints of the contact point location and the velocity ratio. The clearance angles and their derivatives are subsequently used to systematically evaluate kinematic and dynamic quantities of each gear as well as the dynamic tooth load. A pair of rigid tooth spur gears with two revolute clearances is analyzed to illustrate the procedure. The model presented in the paper provides a design method for investigating the effect of bearing tolerances and wear on the evaluation of dynamic tooth load in high speed gearing systems.

Solidification Front Velocity of Ternary Titanium-Aluminides

1995 ◽  
Vol 398 ◽  
Author(s):  
M. Wettlaufer ◽  
J. Laakmann
Keyword(s):  
Experimental Data ◽  
Temperature Measurement ◽  
Solidification Front ◽  
High Speed ◽  
Titanium Aluminides ◽  
Front Velocity ◽  
Experimental Results ◽  
Video System ◽  
High Speed Video ◽  
Bulk Undercooling

ABSTRACTTernary titanium-aluminides with compositions of Ti51Al47Fe2, Ti51A147Cr2 and Ti51Al47Mn2 were investigated with respect to the correlation of their solidification front velocity v and bulk undercooling ΔT. The observation of the solidification front during the recalescence event has been realized using a high speed video system capable of recording up to 12,000 pictures per second. The temperature measurement was carried out by pyrometry, avoiding contact with the sample. The comparison of the experimental data with the LKT-theory (Lipton, Kurz, Trivedi; [1]) refers to a primary (hcp) β-Ti solidification for undercoolings below ΔT≈ 130 K and primary (bcc) α-Ti solidification for ΔT≥ 130 K. For undercoolings ≥ 150 K the theory differs greatly from the experimental results.The maximum undercoolings achieved were 268 K (Ti51Al47Fe2), 285 K (Ti51Al47Cr2) and 280 K (Ti51Al47Mn2), corresponding to a solidification front velocity v ≈ 9-10 m/s for all alloys.

scholarly journals On the mechanism of droplet rolling and spinning in inclined hydrophobic plates in wedge with different wetting states

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bekir Sami Yilbas ◽  
Mubarak Yakubu ◽  
Abba Abdulhamid Abubakar ◽  
Hussain Al-Qahtani ◽  
Ahmet Sahin ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Speed ◽  
Recording System ◽  
Experimental Results ◽  
Phase Contact ◽  
Droplet Motion ◽  
3D Space ◽  
Three Phase ◽  
Tangential Momentum ◽  
Recorded Data

AbstractA water droplet rolling and spinning in an inclined hydrophobic wedge with different wetting states of wedge plates is examined pertinent to self-cleaning applications. The droplet motion in the hydrophobic wedge is simulated in 3D space incorporating the experimental data. A high-speed recording system is used to store the motion of droplets in 3D space and a tracker program is utilized to quantify the recorded data in terms of droplet translational, rotational, spinning, and slipping velocities. The predictions of flow velocity in the droplet fluid are compared with those of experimental results. The findings revealed that velocity predictions agree with those of the experimental results. Tangential momentum generated, via droplet adhesion along the three-phase contact line on the hydrophobic plate surfaces, creates the spinning motion on the rolling droplet in the wedge. The flow field generated in the droplet fluid is considerably influenced by the shear rate created at the interface between the droplet fluid and hydrophobic plate surfaces. Besides, droplet wobbling under the influence of gravity contributes to the flow inside the rolling and spinning droplet. The parallel-sided droplet path is resulted for droplet emerging from the wedge over the dusty surface.

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