scispace - formally typeset
Search or ask a question
Topic

Rotational speed

About: Rotational speed is a research topic. Over the lifetime, 23327 publications have been published within this topic receiving 151696 citations. The topic is also known as: speed of revolution & revolution rate.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the authors measured the heat transfer by convection in the annular gap between the rotating inner cylinder and the stationary outer cylinder and found that the rate of heat transfer increases with rotational speeds under the influence of secondory vortexes by the centrifugal force.
Abstract: The heat transfer by the convection in the annular gap between the rotating inner cylinder and the stationary outer cylinder was measured in the air, spindle oil and mobil oil at varying rotational speeds, cylinder diameters and widths of gap. The results show that characteristics of the flow and heat transfer have two modes. If the rotational speed is low and the width of gap is narrow, namely (vδ/ν)(δ/r)1/2 41, the rate of heat transfer increases with rotational speeds under the influence of secondory vortexes by the centrifugal force, which may be given by [numerical formula]Where U denates the overall coefficient of heat transfer through the gap, δ the width of the gap, λ the thermal conductivity, ν the kinematic viscosity and Pr the Prandtl Number, r and v are the radius and the peripheral velocity of the rotating cylinder respectively.

77 citations

Patent
06 Jul 1978
TL;DR: In this paper, a vertical axis high speed wind turbine with rotational speed control systems is described. But the rotor speed control system is not considered in this paper, since it is assumed that the rotor blades of a proper airfoil are fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft.
Abstract: VERTICAL AXIS WIND TURBINE ABSTRACT OF THE DISCLOSURE Wind turbines are largely divided into vertical axiw wind turbines and propeller (horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.

77 citations

Journal ArticleDOI
TL;DR: In this paper, a combination of tool force monitoring and post weld assessment was used to determine effective welding parameters for the production of good quality friction stir welds at the highest possible welding speeds.

77 citations

Patent
03 Feb 2003
TL;DR: In this paper, a reduction gear ratio n is multiplied by a steering angular speed by a multiplier, and the deviation e achieved by subtracting a motor rotational speed from the multiplication value is integrated and then multiplied by an integration gain to achieve a current target value.
Abstract: A reduction gear ratio n of a reduction gear is multiplied by a steering angular speed by a multiplier, and the deviation e achieved by subtracting a motor rotational speed from the multiplication value is integrated and then multiplied by an integration gain to achieve a current target value The current target value is added with the multiplication value of the deviation e and a proportional gain in a phase compensator to perform phase compensation The phase-compensation result is added with the value achieved by differentiating the motor rotational speed and multiplying the differential value thus achieved by a control gain in an inertia compensator to perform inertia compensation Further, the value achieved by multiplying the motor rotational speed by a control gain is subtracted from the inertia-compensation result in a damping controller to perform damping control, and a final current target value It is achieved from an adder

76 citations

Patent
27 Jan 2003
TL;DR: In this paper, a centrifugal fluid pump assembly includes a motor current flow rate-related data storage section 60 for storing, for a plurality of different predetermined viscosities, predetermined visco-ity-related flow rate data formed from a plurality-of-current-flow-rate relation data at different impeller rotational speeds at predetermined fluid viscosity.
Abstract: A centrifugal fluid pump assembly 1 includes a body section 5 and a control mechanism 6. The body section 5 includes a housing 20, an impeller 21 rotatable within the housing 20, and a motor 34 for rotating the impeller 21. The pump assembly 1 includes a motor current flow rate-related data storage section 60 for storing, for a plurality of different predetermined viscosities, predetermined viscosity-related flow rate data formed from a plurality of motor current flow rate relation data at a plurality of different impeller rotational speeds at predetermined fluid viscosity, a fluid measurement data inputting section 57, an impeller rotational speed measurement function, a motor current measurement function, and a flow rate calculating section 58 for using a fluid viscosity value, an impeller rotational speed value, a measured motor current and data stored in the motor current flow rate-related data storage section 60 to calculate a fluid flow rate.

76 citations


Network Information
Related Topics (5)
Coating
379.8K papers, 3.1M citations
81% related
Heat transfer
181.7K papers, 2.9M citations
81% related
Finite element method
178.6K papers, 3M citations
80% related
Ultimate tensile strength
129.2K papers, 2.1M citations
79% related
Particle
96.5K papers, 1.9M citations
79% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023539
20221,195
2021522
2020773
20191,092
20181,138