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.

Tire pressure and parameter monitoring system and method using accelerometers

Abstract: Method for monitoring an operating condition of a vehicle including determining a longitudinal, a lateral, and/or a vertical acceleration, as well as a wheel rotation speed. Determining from the wheel rotation speed and the longitudinal, the lateral, and/or the vertical acceleration a tire condition, a wheel condition, and/or a suspension condition. Device including an accelerometer at a wheel of a vehicle, a wheel rotation speed sensor, and a microprocessor for determining an operating condition. The accelerometer determining a longitudinal, a lateral, and/or a vertical acceleration. The wheel rotation speed sensor determining a rotation speed of the wheel. The microprocessor electrically coupled to the accelerometer and the wheel rotation speed sensor. System for monitoring an operating condition of a vehicle including an accelerometer for each wheel of the vehicle at an axle-end. Each accelerometer determining a longitudinal, a lateral, and/or a vertical acceleration. Wheel rotation speed sensor for each wheel of the vehicle arranged at an axle-end and determining a rotation speed for each wheel. Microprocessor determining the operating condition including a tire condition, a wheel condition, and/or a suspension condition. The microprocessor electrically coupled to each accelerometer and each wheel rotation speed sensor.

Miniature Single-Disk Viscous Pump (Single-DVP), Performance Characterization

Abstract: The development and testing of a rotating single-disk viscous pump are described. This pump consists of a 10.16 mm diameter spinning disk, and a pump chamber, which are separated by a small gap that forms the fluid passage. The walls of the pump chamber form a C-shaped channel with an inner radius of 1.19 mm, an outer radius of 2.38 mm, and a depth of 40, 73, 117, or 246 μm. Fluid inlet and outlet ports are located at the ends of the C-shaped channel. Experimental flow rate and pressure rise data are obtained for rotational speeds from 100 to 5000 rpm, fluid chamber heights from 40 to 246 μm, flow rates from 0 to 4.75 ml/min, pressure rises from 0 to 31.1 kPa, and fluid viscosities from 1 to 62 mPa s. An analytical expression for the net flow rate and pressure rise, as dependent on the fluid chamber geometry, disk rotational speed, and fluid viscosity, is derived and found to agree with the experimental data. The flow rate and pressure rise of the pump vary nearly linearly with rotational speed. The volumetric flow rate does not change significantly with changes in fluid viscosity for the same rotational speed and pumping circuit. Advantages of the disk pumps include simplicity, ease of manufacture, ability to produce continuous flow with a flow rate that does not vary significantly in time, and ability to pump biological samples without significant alteration or destruction of cells, protein suspension, or other delicate matter.

Influence of Blade Deterioration on Compressor and Turbine Performance

Abstract: Gas turbine operating state determination consists of the assessment of the modification due to deterioration and fault of performance and geometric data characterizing machine components. One of the main effects of deterioration and fault is the modification of compressor and turbine performance maps. Since detailed information about actual modification of component maps is usually unavailable, many authors simulate the effects of deterioration and fault by a simple scaling of the map itself. In this paper, stage-by-stage models of the compressor and the turbine are used in order to assess the actual modification of compressor and turbine performance maps due to blade deterioration. The compressor is modeled by using generalized performance curves of each stage matched by means of a stage-stacking procedure. Each turbine stage is instead modeled as two nozzles, a fixed one (stator) and a moving one (rotor). The results obtained by simulating some of the most common causes of blade deterioration (i.e., compressor fouling, compressor mechanical damage, turbine fouling, and turbine erosion), occurring in one or more stages simultaneously, are reported in this paper. Moreover, compressor and turbine maps obtained through the stage-by-stage procedure are compared with the ones obtained by means of map scaling. The results show that the values of the scaling factors depend on the corrected rotational speed and on the load. However, since the variation in the scaling factors in the operating region close to the design corrected rotational speed is small, the use of the scaling factor as health indices can be considered acceptable for gas turbine health state determination at full load. Moreover, also the use of scaled maps in order to represent compressor and turbine behavior in deteriorated conditions close to the design corrected rotational speed can be considered acceptable.

Failure Analysis of Laminated Composite Pretwisted Rotating Plates

Abstract: In this paper a finite element computational procedure is presented for the determination of first-ply failure strengths of pretwisted rotating plates subjected to centre point transverse load. The finite element model is based on the tensor polynomial failure criterion that contains the maximum stress, maximum strain, Tsai-Hill, Tsai-Wu and Hoffman failure criteria as special cases. A nine-noded three-dimensional degenerated composite shell element is developed and used for the present finite element formulation. Effects of transverse shear deformation and rotary inertia are included. Lagrange's equation of motion is employed to derive the dynamic equilibrium equation considering moderate rotational speeds for which the Coriolis effect is negligible. Finally, the static equilibrium equation is formulated after discarding the time-dependent terms. Failure load computations for rotating cantilever plates with nonlinear pretwist are carried out to investigate the effects of angle of twist, rotational speed ...

Physical Property and Rotational Speed Effects on Heat Transfer in Axially Rotating Liquid/Particulate Canned Foods

Abstract: Particle surface temperatures were measured by liquid crystals that allowed unrestricted motion of the monitored particles. Liquid-particle film heat transfer coefficients (hp) were considerably higher than published values which were determined with particles attached to thermocouple wires. In general, as a result of the particle motion, hp increased with increasing rotational speed and increasing fluid viscosity. Furthermore, hp values were higher for Teflon spheres than for aluminum spheres. Results for the overall (heating medium/container wall/internal liquid) heat transfer coefficients were consistent with published observations.