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 published on a yearly basis
Papers
More filters
TL;DR: In this article, the authors presented a miniature electrically driven two-stage turbocompressor system running at a rated speed of 500 000 r/min with a maximal pressure ratio of 2.3 at a mass flow of 0.5 g/s.
Abstract: The trend in compressors for fuel cells, heat pumps, aerospace, and automotive heating, ventilation, and air-conditioning systems is toward ultracompact size and high efficiency. This can be achieved by using turbocompressors instead of scroll, lobe, or screw compressors, increasing the rotational speed and employing new electrical drive system technology and materials. This paper presents a miniature electrically driven two-stage turbocompressor system running at a rated speed of 500 000 r/min. The design includes the thermodynamic analysis, the electric motor, the inverter, the control, and the system integration with rotor dynamics and thermal considerations. Experimental measurements such as the compressor map are presented for air under laboratory conditions. The two-stage turbocompressor has been tested up to a speed of 600 000 r/min, where a maximal pressure ratio of 2.3 at a mass flow of 0.5 g/s has been reached. To the authors' knowledge, this is the highest rotational speed achieved with an electrically driven turbocompressor.
59 citations
TL;DR: In this article, the authors presented an original methodology to select the most appropriate axial impeller for a specific application, which is based on the intensity of mechanical constraints they produced, evaluated from the macro-shear rate quantified by the spatial derivative of time average velocity fields measured by P.I.V.
59 citations
TL;DR: In this paper, the impact load and instantaneous fluid pressure of transient flow on pump station system under the nonregulative operating conditions, the transient characteristics of an axial flow pump during start-up process are investigated experimentally and numerically.
59 citations
TL;DR: A ball-bearing structure based triboelectric nanogenerator with interdigitative-electrodes was developed that can not only collect energy from rotational kinetic energy, but also serve as a self-powered and multifunctional sensor.
Abstract: A ball-bearing structure based triboelectric nanogenerator (B-TENG) with interdigitative-electrodes was developed that can not only collect energy from rotational kinetic energy, but also serve as a self-powered and multifunctional sensor. The B-TENG relies on the rolling electrification between PTFE balls on Cu interdigitative-electrodes, which delivers an open-circuit voltage of ~40 V and a short-circuit current of ~1.2 μA at a rotating speed of 300 rpm for 4 mm PTFE balls. Using the output signals of B-TENG, a nondestructive detection for the damage of PTFE balls was realized without demounting the bearing. Besides, based on the periodic signals produced from B-TENG, the rotation speed of ball-bearing can be obtained according to the time difference between several cycles.
59 citations
TL;DR: In this paper, the effect of mechanical process parameters such as down force and rotation speed on friction behavior and material removal rate (MRR) was investigated during chemical mechanical polishing (CMP) of sapphire substrate.
59 citations