Showing papers on "Rotational speed published in 2005"

115?kHz tuning repetition rate ultrahigh-speed wavelength-swept semiconductor laser

Abstract: We demonstrate an ultrahigh-speed wavelength-swept semiconductor laser using a polygon-based wavelength scanning filter. With a polygon rotational speed of 900 revolutions per second, a continuous wavelength tuning rate of 9200 nm/ms and a tuning repetition rate of 115 kHz were achieved. The wavelength tuning range of the laser was 80 nm centered at 1325 nm, and the average polarized output power was 23 mW.

Lap Joint of A5083 Aluminum Alloy and SS400 Steel by Friction Stir Welding

Abstract: A lap joint of A5083 aluminum alloy and SS400 steel was produced by Friction Stir Welding (FSW) using the various process parameters such as rotational speed, traverse speed and pin depth. The variations of welding parameters produced various characteristic interfaces and had conspicuous influences on the joint properties. Increasing the rotational speed decreased the shear load of the joint due to producing a thick FeAl 3 intermetallic compound (IMC) at the interface. When traverse speed increased, the shear load increased because IMC thickness at the interface decreased, however, when the speed was so high, an incomplete interface was formed. Increasing the pin depth produced a thick FeAl 3 IMC phase and an incomplete interface that directly deteriorated the shear load of the joint.

Substrate processing apparatus and method

Abstract: The substrate processing apparatus has substrate holding mechanisms (14) for holding the substrate (W) under a holding force which is changed according to a rotational speed of the substrate holding mechanisms (14), a substrate rotation mechanism (22) for rotating the substrate holding mechanisms (14) to rotate the substrate (W) held by the substrate holding mechanisms (14), and a treatment liquid supply mechanism (12, 15, 19) for supplying a treatment liquid to a desired portion of the substrate (W) held by the substrate holding mechanisms (14).

Numerical and Experimental Analysis of an Axial Flow Left Ventricular Assist Device: The Influence of the Diffuser on Overall Pump Performance

Abstract: Thousands of adult cardiac failure patients may benefit from the availability of an effective, long-term ventricular assist device (VAD). We have developed a fully implantable, axial flow VAD (LEV-VAD) with a magnetically levitated impeller as a viable option for these patients. This pump's streamlined and unobstructed blood flow path provides its unique design and facilitates continuous washing of all surfaces contacting blood. One internal fluid contacting region, the diffuser, is extremely important to the pump's ability to produce adequate pressure but is challenging to manufacture, depending on the complex blade geometries. This study examines the influence of the diffuser on the overall LEV-VAD performance. A combination of theoretical analyses, computational fluid (CFD) simulations, and experimental testing was performed for three different diffuser models: six-bladed, three-bladed, and no-blade configuration. The diffuser configurations were computationally and experimentally investigated for flow rates of 2-10 L/min at rotational speeds of 5000-8000 rpm. For these operating conditions, CFD simulations predicted the LEV-VAD to deliver physiologic pressures with hydraulic efficiencies of 15-32%. These numerical performance results generally agreed within 10% of the experimental measurements over the entire range of rotational speeds tested. Maximum scalar stress levels were estimated to be 450 Pa for 6 L/min at 8000 rpm along the blade tip surface of the impeller. Streakline analysis demonstrated maximum fluid residence times of 200 ms with a majority of particles exiting the pump in 80 ms. Axial fluid forces remained well within counter force generation capabilities of the magnetic suspension design. The no-bladed configuration generated an unacceptable hydraulic performance. The six-diffuser-blade model produced a flow rate of 6 L/min against 100 mm Hg for 6000 rpm rotational speed, while the three-diffuser-blade model produced the same flow rate and pressure rise for a rotational speed of 6500 rpm. The three-bladed diffuser configuration was selected over the six-bladed, requiring only an incremental adjustment in revolution per minute to compensate for and ease manufacturing constraints. The acceptable results of the computational simulations and experimental testing encourage final prototype manufacturing for acute and chronic animal studies.

Method for controlling a wind power plant and corresponding wind power plant

Abstract: The performance or rotational speed of a wind power plant is reduced above a defined threshold value not on the base of a measured wind speed, but on the basis of an input quantity which is easily physically detectable by an automatic control technology and represents a good indicator for the plant charge. Said invention is characterised in that the input quantity is embodied in the form of the angle of the rotor blades in such a way that the reduction of the performance or rotational speed is adjusted when the limit value corresponding to the angle of the rotor blades is attained.

Measurement of a fluid parameter in a pressure support system

Abstract: A pressure support system has a motor, a switching element that supplies power to motor windings, and a blower coupled to the motor. Rotation of the blower elevates a pressure of fluid in a patient circuit coupled to an outlet of the blower. A rotational speed controller maintains the motor at a set rotational speed corresponding to a selected pressure for the fluid in the patient circuit. The rotational speed of the motor is maintained by a switching signal provided by a rotational speed controller to the switching element to control the actuation of the switching element. A fluid parameter monitoring portion monitors a parameter associated with the flow of fluid in the patient circuit, such as the magnitude, direction, or volume, based on a characteristic, such as duty cycle, of the switching signal, or based on a characteristic of a control signal that is used to generate the switching signal.

Liquid-conducting electrical household appliance

Abstract: Disclosed is an electrical household appliance comprising a chamber that is at least partially filled with liquid during operation of the appliance, a motor (9)-driven pump (5) for sucking liquid from said chamber, and a monitoring device (31) for detecting the rotational speed and the power of the motor (9), comparing detected values for the rotational speed and power to a predefined characteristic, and signaling an exceptional state if the comparison indicates that the detected values deviate significantly from the characteristic.

Rotation control device, rotation control method and construction machine

Abstract: A control device (50) for an electrically rotated shovel, in which a rotation speed factor is created according the condition set by a fuel dial (13) or the condition selected by a mode change switch (14), and the magnitude of a target speed command value is varied to vary the rotation speed of a rotating body (4). As a result, when the speed of an engine is reduced by operation of the fuel dial (13) or the mode change switch (14), the rotation speed of the rotating body (4) can be reduced accordingly, and when the engine speed is increased, the rotation speed can be increased. This can provide drive comfort almost similar to that obtained when the rotating body (4) is rotated by an ordinary hydraulic system. As a consequence, even if a user changes a shovel from a conventional hydraulic shovel to this electrically rotated shovel, the user does not have a strange feeling.

Engine spin-up control with natural torque smoothing

Abstract: A hybrid vehicle includes an engine having at least one cylinder and an electric machine that drives the engine during a start-up period. A control module monitors a rotational speed of the engine and regulates torque generated by the electric machine based on the rotational speed during the start-up period and a maximum discharge power available to power the electric machine.

Hydraulic pressurizer system

Abstract: A hydraulic pressurizer system comprises a drive source, which drives a hybrid vehicle, a mechanical oil pump, which is driven by the drive source, an electrical motor, which is activated by a 12V battery, an electrical oil pump, which is driven by the electrical motor, and a control unit, which activates the electrical motor. The pressurizer further comprises a ratio-change mechanism, which is activated by hydraulic oil supplied by the mechanical oil pump and by the electrical oil pump to establish a speed change ratio, at which the rotational driving force of the drive source is transmitted to wheels with a rotational speed change. The control unit memorizes a characteristic value, which is specified from the temperature of the hydraulic oil and from the rotational speed of the electrical motor, and a threshold value for the rotational speed of the electrical motor, which threshold value corresponds to the characteristic value.

Local Heat/Mass Transfer Characteristics on a Rotating Blade With Flat Tip in a Low Speed Annular Cascade: Part 2 — Tip and Shroud

Abstract: The local heat/mass transfer characteristics on the tip and shroud were investigated using a low speed rotating turbine annular cascade. Time-averaged mass transfer coefficients on the tip and shroud were measured using a naphthalene sublimation technique. A low speed wind tunnel with a single stage turbine annular cascade was used. The turbine stage is composed of sixteen guide plates and blades. The chord length of blade is 150 mm and the mean tip clearance is about 2.5% of the blade chord. The tested Reynolds number based on inlet flow velocity and blade chord is 1.5×105 and the rotational speed of the blade is 255.8 rpm at design condition. The results were compared with the results for a stationary blade and the effects of incidence angle of incoming flow were examined for incidence angles ranging from −15 to +7 degree. The off-design test conditions are obtained by changing the rotational speed with a fixed incoming flow velocity. Flow reattachment on the tip near the pressure side edge dominates the heat transfer on the tip surface. Consequently, the heat/mass transfer coefficients on the blade tip are about 1.7 times as high as those on the blade surface and the shroud. However, the heat transfer on the tip is about 10% lower than that for the stationary case due to reduced leakage flow with the relative motion. The peak regions due to the flow reattachment are reduced and shifted toward the trailing edge and additional peaks are formed near the leading edge region with decreasing incidence angles. But, quite uniform and high values are observed on the tip with positive incidence angles. The time-averaged heat/mass transfer on the shroud surface has similar a level to that of the stationary cases.Copyright © 2005 by ASME

Turbine engine disk spacers

Abstract: A gas turbine engine rotor stack includes one or more longitudinally outwardly concave spacers. Outboard surfaces of the spacers may be in close facing proximity to inboard tips of vane airfoils. The spacers may provide a longitudinal compression force that increases with rotational speed.

Control apparatus and method for internal combustion engine

Abstract: A working angle (lift amount) of an intake valve is set to a predetermined first set value A 1 during a period from when starting of the engine is initiated until when the engine is shifted to an initial combustion state, and the working angle is changed to a second set value A 2 (=previous value (initial value is A 1 )+α) that is larger than the first set value A 1 during a period from when the engine is shifted to the initial combustion state until when the engine is shifted to a perfect combustion state. When an engine rotational speed becomes equal to or higher than a reference rotational speed n 1 , it is determined that the engine has been shifted to the perfect combustion state, after which an engine starting routine ends.

Belt drive control method, belt-drive control device, and image forming apparatus

Abstract: A rotational speed of a first roller and a time required for a second roller to make one rotation are measured. A controller calculates an amplitude and a phase of fluctuation in a rotational speed in one rotation period of the first roller while the first roller is rotated by a predefined angle based on the speed and the time. The controller corrects measured speed of the first roller based on the amplitude and the phase, and controls a driving roller based on corrected speed.

Parameter sensitivities affecting the flutter speed of a MW-sized blade.

Abstract: With the current trend toward larger and larger horizontal axis wind turbines, classical flutter is becoming a more critical issue. Recent studies have indicated that for a single blade turning in still air the flutter speed for a modern 35 m blade occurs at approximately twice its operating speed (2 per rev), whereas for smaller blades (5-9 m), both modern and early designs, the flutter speeds are in the range of 3.5-6 per rev. Scaling studies demonstrate that the per rev flutter speed should not change with scale. Thus, design requirements that change with increasing blade size are producing the concurrent reduction in per rev flutter speeds. In comparison with an early small blade design (5 m blade), flutter computations indicate that the non rotating modes which combine to create the flutter mode change as the blade becomes larger (i.e., for the larger blade the second flapwise mode, as opposed to the first flapwise mode for the smaller blade, combines with the first torsional mode to produce the flutter mode). For the more modern smaller blade design (9 m blade), results show that the non rotating modes that couple are similar to those of the larger blade. For the wingsmore » of fixed-wing aircraft, it is common knowledge that judicious selection of certain design parameters can increase the airspeed associated with the onset of flutter. Two parameters, the chordwise location of the center of mass and the ratio of the flapwise natural frequency to the torsional natural frequency, are especially significant. In this paper studies are performed to determine the sensitivity of the per rev flutter speed to these parameters for a 35 m wind turbine blade. Additional studies are performed to determine which structural characteristics of the blade are most significant in explaining the previously mentioned per rev flutter speed differences. As a point of interest, flutter results are also reported for two recently designed 9 m twist/coupled blades.« less

Single-disk and double-disk viscous micropumps

Abstract: The development and testing of two versions of a novel micropump are described: (i) the single-disk viscous pump and (ii) the double-disk viscous pump. The rotational movement of the disk(s) induces viscous stresses on the fluid that forces the fluid from an inlet channel, and then, through the pumping volume above the single disk, or between the two disks. A wiper acts to “wipe” the fluid from the disk(s) toward the outlet channel. The fluid flow through the double-disk pump is visualized using a red Rhodamine dye that is injected into the fluid passage upstream of the pumping volume. These visualizations provide information on the relative importance of viscous forces, centrifugal forces, and static pressure variations. The maximum flow rates and pressure rises are 1.0 ml/min, 643 Pa, and 2.1 ml/min 1.19 kPa for the single-disk and double-disk pumps, respectively, for a rotational speed of 5000 rpm, a disk diameter of 2.38 mm, and a gap height of 103 μm, and supplied power to the motor of 7 W. The disk pumps are fabricated using precision machining techniques employed on a lathe and milling machine. Advantages of the viscous disk pumps include: simplicity of design, planar structure, continuous flow, well controlled flow rate, and, if desired, the ability to augment mixing in the fluid.

Control device for internal combustion engine

Abstract: PROBLEM TO BE SOLVED: To suitably perform fuel cut and cancellation of the fuel cat of an internal combustion engine. SOLUTION: When deceleration operation of a vehicle (engine) is continuously performed (S103), correction fuel cut control for performing learning correction of recovery rotation speed Na for performing cancellation of fuel cut and assist rotation speed Nb for assisting operation of the engine is executed (S104). When occurrence of engine stall is estimated (S105), learning correction of the recovery rotation speed Na and the assist rotation speed Nb is performed based on rotation speed Nc of the engine at that time (S106). Moreover, assist control for assisting operation of the engine is performed and execution of correction fuel cut control is canceled (S107). COPYRIGHT: (C)2006,JPO&NCIPI

Method and apparatus for reducing rotor blade deflections, loads, and/or peak rotational speed

Abstract: A method for reducing at least one of loads, deflections of rotor blades, or peak rotational speed of a wind turbine includes storing recent historical pitch related data, wind related data, or both. The stored recent historical data is analyzed to determine at least one of whether rapid pitching is occurring or whether wind speed decreases are occurring. A minimum pitch, a pitch rate limit, or both are imposed on pitch angle controls of the rotor blades conditioned upon results of the analysis.

Methods and systems for medical imaging

Abstract: Methods and systems for medical imaging are provided. The system includes a gantry assembly having a stator, a first rotor rotatably coupled to the stator, the first rotor configured to rotate about an examination axis at a first rotational speed, and a second rotor rotatably coupled to at least one of the stator and the first rotor, the second rotor configured to rotate about the examination axis at the first and a second rotational speed, the second rotational speed being greater than the first rotational speed, the first and second rotors configured to be locked in position with respect to each other during rotation at the first rotational speed, the first rotor configured to be locked in position with respect to the stator during rotation of the second rotor at the second rotational speed.