Results 241 to 250 of about 510,808 (288)

An experimental investigation on the influence of an assembly preload on the hysteresis, the drag torque, the lift-off speed and the thermal behavior of three-pad air foil journal bearings

Tribology International, 2019
Rotors supported by air foil journal bearings often show distinctive subharmonic oscillations arising from the nonlinear force-displacement relationship of the elastic foil structure. Also, air film induced instabilities may be observed in such bearings.
Marcel Mahner, M. Bauer, Andreas Lehn, B. Schweizer   +3 more
semanticscholar   +1 more source

Method and apparatus for monitoring of downhole dynamic drag and torque of drill-string in horizontal wells

Journal of Petroleum Science and Engineering, 2018
Tianshou Ma
exaly   +2 more sources

Drag, lift, and torque on a prolate spheroid resting on a smooth surface in a linear shear flow

, 2021
Understanding the aerodynamic forces on particles resting on a surface is important for studies of surface contamination, non-contact sampling, and environmental and health assessments.
P. Fillingham, R. S. Vaddi, Andrew Bruning, Gunnar Israel, I. Novosselov   +4 more
semanticscholar   +1 more source

High-resolution 3D CFD multiphase simulation of the flow and the drag torque of wet clutch discs considering free surfaces

Tribology International, 2019
The viscous shearing of the cooling oil within disengaged wet clutches causes a substantial amount of power loss. In order to optimise efficiency, it is the objective of current research to minimise these losses to a great extent. In addition to test rig
T. Neupert, D. Bartel
semanticscholar   +1 more source

Calculation and Analysis on Drag Torque of the Wet Clutch

Applied Mechanics and Materials, 2015
In order to study the drag torque characteristics of wet clutch, the drag torque with no groove friction plates and with radial groove friction plates were analysed separately, and the influence factors of the drag torque such as the lubricating oil temperature, the depth of the groove, the average gap between the friction plates were also discussed ...
Li Ying Miao, Xiu Sheng Cheng, Xue Song Li, Li Chen Yang   +3 more
openaire   +1 more source

Simulation Research on the Drag Torque of Disengaged Wet Clutches

2019 IEEE 5th International Conference on Mechatronics System and Robots (ICMSR), 2019
In order to evaluate the drag torque of wet clutches in high speed zone, a gas-fluid two phases mathematical model was established with grooves in consideration based on the theory of viscous fluid dynamics.
Ha Pan, Xiaojun Zhou
semanticscholar   +1 more source

Torque and Drag Modeling Advanced Techniques and Troubleshooting

SPE Annual Technical Conference and Exhibition, 2012
Abstract Extreme torque and drag (T&D), especially when unplanned, is a primary limiter to the reach of horizontal and extended-reach wells. Many engineers use T&D software models without a thorough understanding of how the input affects the calculations in the program.
John McCormick, Gefei Liu
openaire   +1 more source

Model for the prediction of drag torque characteristics in wet clutch with radial grooves

Proceedings of the Institution of mechanical engineers. Part D, journal of automobile engineering, 2018
Drag torque can cut down the efficiency of the vehicle transmission system. So it should be reduced on the premise of normal vehicle lubrication and heat dissipation.
Lin Zhang, Chao Wei, J. Hu
semanticscholar   +1 more source

Torque and Drag in Directional Wells-Prediction and Measurement

Journal of Petroleum Technology, 1984
Summary A computer model has been developed to predict drillstring torque and drag, and a versatile rotary torque meter has been built to use in calibrating the model. The principle of the predictive model is that torque and drag forces in a directional wellbore are primarily caused by sliding friction.
C.A. Johancsik, D.B. Friesen, Rapier Dawson   +2 more
openaire   +1 more source

Designing Well Paths to Reduce Drag and Torque

SPE Drilling Engineering, 1987
Summary A deviated well with an undersection trajectory (i.e., a trajectory lying below the conventional tangent section and constantly building to target) can exhibit lower drag and torque than a conventional well geometry in certain circumstances. The influence of well geometry on drag and torque is discussed, making use of the results
M. C. Sheppard, C. Wick, T. Burgess
openaire   +1 more source