Laminar Free Convection from a Rotating Radial Plate

1972 ◽  
Vol 94 (4) ◽  
pp. 419-424 ◽  
Author(s):  
G. S. H. Lock ◽  
R. S. Ko
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
High Speed ◽  
Numerical Solutions ◽  
Temperature Profiles ◽  
Governing Equations ◽  
High Speed Rotation ◽  
Convection Problem ◽  
Speed Rotation ◽  
Radial Plate

The paper presents a theoretical analysis of conduction through, and free convection from, a radial plate rotating in a synchronous environment of air. The plate resembles a tapered, radially protruding fin heated at the root. Ordering of the governing equations reveals three controlling parameters, under the condition of steady high-speed rotation. Numerical solutions to the combined conduction–convection problem reveal the effect of the parameters on the velocity and temperature profiles, the overall heat-transfer relation, and the fin effectiveness.

Laminar Free Convection on a Curved Wall

1971 ◽  
Vol 38 (4) ◽  
pp. 1081-1083
Author(s):  
K. W. McAlister
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Temperature Variation ◽  
Newtonian Fluid ◽  
Numerical Solutions ◽  
Similarity Solutions ◽  
Governing Equations ◽  
Transfer Rates ◽  
Arbitrary Temperature ◽  
Free Parameters

Laminar free convection of a Newtonian fluid passing over a curved wall having arbitrary temperature variation is considered. The governing equations are presented and the method of free parameters is used to investigate the existence of similarity solutions. It is found that similarity solutions do exist when the wall inclination and temperature are required to be certain functions of the coordinate parallel to the wall. Numerical solutions to several example cases are presented which indicate that higher heat-transfer rates are possible on a wall which is concave with respect to the fluid.

Multipass Serpentine Cooling Designs for Negating Coriolis Force Effect on Heat Transfer: 45-deg Angled Rib Turbulated Channels

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Prashant Singh ◽  
Yongbin Ji ◽  
Srinath V. Ekkad
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Thermal Stresses ◽  
Suction Side ◽  
Reynolds Numbers ◽  
Liquid Crystal Thermography ◽  
Wide Range ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Stationary Conditions

Rotation-induced Coriolis and centrifugal buoyancy forces result in significant modification of cooling characteristics of blade pressure and suction side internal walls. The nonuniformity in cooling, coupled with high-speed rotation, results in increased levels of thermal stresses. To address this problem, this study presents two multipassage configurations featuring 45-deg angled turbulators, in four- and six-passage designs. Experiments were carried out under stationary and rotating conditions using transient liquid crystal thermography to measure detailed heat transfer coefficient. It has been shown through experimental data that heat transfer characteristics of the new configurations’ pressure and suction side internal walls were very similar under rotating conditions, at both local and global scales. The heat transfer levels under rotating conditions were also similar to those of the stationary conditions. The contribution of multiple passages connected with 180-deg bends toward overall frictional losses has been evaluated in terms of pumping power and normalized friction factor. The configurations are ranked based on their thermal hydraulic performances over a wide range of Reynolds numbers. The four-passage ribbed configuration had slightly higher heat transfer levels compared with those of the corresponding six-passage ribbed configuration.

scholarly journals Sound Noise Generated from Ball Bearing in High Speed Rotation

1978 ◽  
Vol 21 (158) ◽  
pp. 1306-1310 ◽  
Author(s):  
Akio NAGAMATSU ◽  
Masaho FUKUDA
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
High Speed Rotation ◽  
Speed Rotation

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

Research on Calibration Method of Tire Dynamic Balance Detection System

2012 ◽  
Vol 542-543 ◽  
pp. 828-832 ◽  
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Lian Fang Zhao
Keyword(s):  
High Speed ◽  
Detection System ◽  
Dynamic Balance ◽  
Calibration Method ◽  
Engineering Practice ◽  
Influence Coefficient ◽  
Quality Factors ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Upper Rim

Tire dynamic balance detection plays an important part in tire quality detection area. This paper uses the two-sided balance method to obtain the unbalance of the tire. According to the engineering practice, builds kinetic model and then introduces the calculating principle and operating procedures. In order to accurately determine the influence coefficient, a calibration method without tire is put forward. Further more, this new method is able to eliminate the unbalance caused by non-quality factors to some extent. But this method is presented based on the relative position invariance of the upper rim and lower rim, even both of them are under high-speed rotation situation. Finally, the experimental data acquired from both of the two methods are compared. The calibration method without tire is proved to be more feasible, efficient and accurate.

Improvement of Silver Recovery Efficiency by High-Speed Rotation

2003 ◽  
Vol 439 ◽  
pp. 156-162
Author(s):  
A. Da Camara ◽  
Joaquín Lira-Olivares ◽  
Soo Wohn Lee ◽  
H.D. Park ◽  
Y.S. Park
Keyword(s):  
High Speed ◽  
Recovery Efficiency ◽  
Silver Recovery ◽  
High Speed Rotation ◽  
Speed Rotation

High-speed Rotation and Speed Stability of the Sodium-driven Flagellar Motor inVibrio alginolyticus

1995 ◽  
Vol 251 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Kazumasa Muramoto ◽  
Ikuro Kawagishi ◽  
Seishi Kudo ◽  
Yukio Magariyama ◽  
Yasuo Imae ◽  
...  
Keyword(s):  
High Speed ◽  
Flagellar Motor ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Speed Stability
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