Results 11 to 20 of about 303 (97)

On the Instability Threshold of Journal Bearing Supported Rotors

International Journal of Rotating Machinery, 2014
Journal bearing supported rotors present two kinds of self-excited vibrations: oil-whirl and oil-whip. The first one is commonly masked by the rotor unbalance, hence being rarely associated with instability problems.
Ricardo Ugliara Mendes, Katia Lucchesi Cavalca   +1 more
doaj   +1 more source

Induced Unbalance as a Method for Improving the Dynamic Stability of High-Speed Turbochargers

International Journal of Rotating Machinery, 2011
The high-speed diesel engine turbocharger is known to have subsynchronous vibrations for a wide speed range. The bearing fluid-film instability is the main source of the vibration.
R. Gordon Kirk, Ali A. Alsaeed
doaj   +1 more source

Analysis of the Instability Phenomena Caused by Steam in High-Pressure Turbines

Shock and Vibration, 2011
Instability phenomena in steam turbines may happen as a consequence of certain characteristics of the steam flow as well as of the mechanical and geometrical properties of the seals.
Paolo Pennacchi, Andrea Vania
doaj   +1 more source

Dynamic stability of herringbone-grooved journal gas bearing

Nihon Kikai Gakkai ronbunshu, 2014
As the herringbone-grooved journal gas bearing can rotate silently at high speed with low friction, and moreover it can be small-sized, it is used a lot in the fields such as information appliances.
Katsuhisa FUJITA, Yusuke KIRITANI
doaj   +1 more source

Comparison of Unsteady Low- and Mid-Fidelity Propeller Aerodynamic Methods for Whirl Flutter Applications

Applied Sciences
Aircraft configurations with propellers have been drawing more attention in recent times, partly due to new propulsion concepts based on hydrogen fuel cells and electric motors.
Christopher Koch, Nils Böhnisch, Hendrik Verdonck, Oliver Hach, Carsten Braun   +4 more
doaj   +1 more source

Experimental Study of Spatiotemporal Variations in Lab-Scale Fire Whirls

Journal of Combustion
This study focused on the unsteady behavior of fire whirls. A laboratory-scale fire whirl was generated, and temporal variations in flame height were measured from images taken by a high-speed camera and subjected to frequency analysis.
Mariko Watanabe, Yuya Oguri
doaj   +1 more source

Suppression of unstable whirl vibration of a truncated conical rotor with spiral fins partially immersed in water.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 1987
A truncated conical rotor undergoes unstable vibration when it is partially immersed in water and driven at a supercritical speed. The unstable vibration is a forward whirl and occurs at a limited range of rotation speed and rotor immersion in water.
openaire   +2 more sources

Dynamic Coupling Simulation Model of Dynamic Push-the-Bit Rotary Steerable System and its Application

Shiyou jixie
To address the issues frequently encountered during wellbore trajectory control using rotary steerable system （RSS） with PDC bit， such as excessive reactive torque in the drill string system， unstable build-up rate of the RSS， and large deviation of the ...
Kuang Yuchun, He Liangyuan, Yu Dongbing, Han Yiwei, Chen Hualong   +4 more
doaj  

Negative potential energy content analysis in cracked rotors whirl response. [PDF]

Sci Rep, 2021
Al-Shudeifat MA, Alhammadi FK.
europepmc   +1 more source

Unstable vibration of rotor due to contact friction. Critical contact condition for on-set of unstable whirling.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C, 1985
Noriaki HAGIWARA, Takashi KONO
openaire   +2 more sources