scholarly journals Static and dynamic behavior of polymer mixtures of similar chemical constitution and different macromolecular architecture

2001 ◽  
Author(s):  
Εμμανουήλ Δοξαστάκης
Keyword(s):  
Dynamic Behavior ◽  
Polymer Mixtures ◽  
Similar Chemical ◽  
Chemical Constitution ◽  
Macromolecular Architecture

THE HYDROGENATION OF ALBERTA COALS: II. COMPARATIVE DATA ON THIRTEEN COALS OF VARIOUS RANKS AND TWO SUSPENSION MEDIA, TETRALIN AND LIQUID PETROLATUM

1935 ◽  
Vol 13b (1) ◽  
pp. 11-27 ◽  
Author(s):  
E. H. Boomer ◽  
A. W. Saddington ◽  
J. Edwards
Keyword(s):  
Volatile Oil ◽  
Comparative Data ◽  
Free Basis ◽  
Similar Chemical ◽  
Chemical Constitution ◽  
Hydrogen Carrier ◽  
Commercial Process ◽  
Oil Gas ◽  
Solvent Action

Thirteen Alberta coals of graded rank have been hydrogenated in the presence of tetralin at 450 °C. and in the presence of liquid petrolatum at 425 °C. Tetralin is superior to liquid petrolatum owing, it is believed, to its efficiency as a hydrogen carrier and its solvent action on coal. The use of tetralin or materials of similar chemical constitution in a commercial process is considered possible, and the greater cost of the medium might be more than offset by its greater efficiency as compared with the ordinary heavy oils.A definite progression from old to young coals has been shown by increasing yields of volatile oil, gas and water, and decreasing yields of pitch and coke.Conversions of coal to oils, water and gas as high as 96.7% with tetralin and 81.6% with liquid petrolatum on the dry, ash-free basis have been reported.

Ball bearing turbocharger vibration management: application on high speed balancer

2020 ◽  
Vol 21 (6) ◽  
pp. 619
Author(s):  
Kostandin Gjika ◽  
Antoine Costeux ◽  
Gerry LaRue ◽  
John Wilson
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Ball Bearing ◽  
Squeeze Film ◽  
Design And Technology ◽  
Squeeze Film Damper ◽  
Damping Coefficients ◽  
Bearing Loads ◽  
Stiffness And Damping

Today's modern internal combustion engines are increasingly focused on downsizing, high fuel efficiency and low emissions, which requires appropriate design and technology of turbocharger bearing systems. Automotive turbochargers operate faster and with strong engine excitation; vibration management is becoming a challenge and manufacturers are increasingly focusing on the design of low vibration and high-performance balancing technology. This paper discusses the synchronous vibration management of the ball bearing cartridge turbocharger on high-speed balancer and it is a continuation of papers [1–3]. In a first step, the synchronous rotordynamics behavior is identified. A prediction code is developed to calculate the static and dynamic performance of “ball bearing cartridge-squeeze film damper”. The dynamic behavior of balls is modeled by a spring with stiffness calculated from Tedric Harris formulas and the damping is considered null. The squeeze film damper model is derived from the Osborne Reynolds equation for incompressible and synchronous fluid loading; the stiffness and damping coefficients are calculated assuming that the bearing is infinitely short, and the oil film pressure is modeled as a cavitated π film model. The stiffness and damping coefficients are integrated on a rotordynamics code and the bearing loads are calculated by converging with the bearing eccentricity ratio. In a second step, a finite element structural dynamics model is built for the system “turbocharger housing-high speed balancer fixture” and validated by experimental frequency response functions. In the last step, the rotating dynamic bearing loads on the squeeze film damper are coupled with transfer functions and the vibration on the housings is predicted. The vibration response under single and multi-plane unbalances correlates very well with test data from turbocharger unbalance masters. The prediction model allows a thorough understanding of ball bearing turbocharger vibration on a high speed balancer, thus optimizing the dynamic behavior of the “turbocharger-high speed balancer” structural system for better rotordynamics performance identification and selection of the appropriate balancing process at the development stage of the turbocharger.

Prediction of gear wear for the estimation of solar array drive dynamic behavior

2006 ◽  
Vol 12 (4) ◽  
pp. 33-37
Author(s):  
V.E. Shatikhin ◽  
◽  
L.P. Semenov ◽  
V.S. Khoroshylov ◽  
V.M. Popel' ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Solar Array

Dependence of the Dynamic Behavior of Supersaturated Silicic Acid on the Surface Area of the Solid Phase

2008 ◽  
Author(s):  
Yuichi Niibori ◽  
Yasunori Kasuga ◽  
Hiroshi Kokubun ◽  
Kazuki Iijima ◽  
Hitoshi Mimura
Keyword(s):  
Surface Area ◽  
Dynamic Behavior ◽  
Silicic Acid ◽  
Solid Phase
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