Abstract: Processes for controlling the flowrate of and recovering energy from a gas stream in a processing unit are described. One process comprises directing a portion of the gas stream through one or more variable-resistance power-recovery turbines to control the flowrate of the gas stream and generate electric power therefrom; and controlling the pressure and temperature of the gas stream so that the gas exiting the power-recovery turbine remains in the gas phase.

Abstract: A rocker arm assembly that includes an electromagnetic latch assembly with a latch pin and an actuator operative to actuate the latch pin between a first position and a second position. The actuator includes an electromagnet powered through a coil circuit. The rocker arm assembly further includes a switch in a switch circuit. The coil circuit and the switch circuit are connected in parallel. Moving the latch pin between the first position and the second position opens and closes the switch. In an alternate embodiment, relative motion of two rocker arms opens and closes the switch. The rocker arm assembly allows OBD information to be obtained without making electrical connections to the rocker arm assembly other than ones provided to power the electromagnet.

Abstract: An apparatus facilitates multiple paths or circuits through an engine and remote housing for an oil filter. The apparatus includes a first oil filter chamber housing a first oil filter, a second oil filter chamber housing a second oil filter, a first output of the remote housing configured to provide a path from the first oil filter chamber housing to bearings of an engine, a second output of the remote housing configured to provide a path from the second oil filter chamber housing to a sump of the engine, and an input of the remote housing configured to provide a path from an oil pump of the engine to the first oil filter chamber housing.

Abstract: An exhaust pulse balance chamber comprising a circular collar, mid-section that bulges at its center, skirt, and right and left legs, all of which are sealed to the exterior environment and in fluid communication with one another. The outer diameter of the skirt increases in width but not in depth from the proximal end of the skirt to the distal end of the skirt, which is configured to receive the right and left legs. Each leg is bent at a 30-degree angle relative to the central longitudinal axis of the exhaust pulse balance chamber. The invention includes a method of using the exhaust pulse balance chamber to convert a vehicle from a dual-in, single-out exhaust system to a dual-in, dual-out exhaust system.

Abstract: A heating device includes a heating element in the form of a metal foam, and a case defined by a side wall that extends along a longitudinal axis. The metal foam is housed in the case. An electrical thermal insulator is arranged between the metal foam and the case. The heating device includes at least one electrode and the metal foam includes a zone configured to receive the at least one electrode.

Abstract: Methods and systems are provided to heat a catalyst of an after-treatment system for a vehicle. The after-treatment system is powered by a battery. An operational parameter of the battery and the driving mode of the vehicle is determined. After receiving an indication that a first operational parameter threshold has been surpassed and a torque demand of the vehicle has been predicted, heat is provided to the catalyst of the after-treatment system based on the predicted torque demand of the vehicle surpassing a second operational parameter threshold.

Abstract: A method of manufacturing an electrically heated catalyst device includes preparation of a metal thin plate as a material of a metal electrode layer. The metal thin plate includes wiring portions, a base, a terminal portion, a second base, and a pseudo terminal portion. The method includes supplying current between the terminal portion and the pseudo terminal portion of the metal thin plate after fixing layers are formed; and forming the metal electrode layer by removing a portion of the metal thin plate between a smallest cross-sectional area portion and a distal end of the pseudo terminal portion through melting and cutting of the smallest cross-sectional area portion using the Joule heat generated by the supplied current. The smallest cross-sectional area portion is a part of the metal thin plate that has a smallest area in a cross section perpendicular to the extending direction of the wiring portions.

Abstract: An exhaust control system for a vehicle includes at least one temperature sensor, positioned within an exhaust system of the vehicle, that is configured to generate a measurement signal indicative of at least one of an inlet temperature and an outlet temperature of a diesel oxidation catalyst (DOC). An exhaust control module is configured to turn on an exhaust burner on to heat exhaust flowing through the exhaust system, determine a total stored heat within the DOC based in part on the measurement signal, subsequent to turning on the exhaust burner, turn off the exhaust burner based on an upper threshold of the total stored heat, and, subsequent to turning off the exhaust burner, turn on the exhaust burner based on a lower threshold of the total stored heat, wherein the lower threshold is less than the upper threshold.

Abstract: A nitrous oxide (N2O) removal catalyst composite is provided, comprising a N2O removal catalytic material on a substrate, the catalytic material comprising a rhodium (Rh) component supported on a ceria-based support, wherein the catalyst composite has a H2-consumption peak of about 100° C. or less as measured by hydrogen temperature-programmed reduction (H2-TPR). Methods of making and using the same are also provided.

Abstract: Catalytic converter anti-theft devices and systems are described.

Abstract: A clutch device for a vehicle fan includes a drive-side clutch element and an output-side clutch element. The clutch device includes a locking mechanism configured between the drive-side clutch element and the output-side clutch element so that a rotary connection established between the drive-side clutch element and the output-side clutch element is released when a drive-side rotational speed reduces in comparison with an output-side rotational speed.

Abstract: Aspects of the present invention relate to an apparatus comprising at least two chambers, each chamber comprising at least one wall defining the chamber, a fluid inlet and a fluid outlet through the wall of the chamber and an opening separate from the fluid inlet and fluid outlet. The fluid inlet and fluid outlet are configured such that a fluid enters the chamber via the fluid inlet and exits via the fluid outlet. A gas enters the chamber via the fluid inlet and exits the chamber via the opening, wherein the opening of each of the chambers is fluidly connected to a common fluid reservoir. The apparatus may be used for degassing multiple coolant circuits in a vehicle.

Abstract: A nozzle device according to some embodiments includes an annular nozzle plate, an annular nozzle mount defining a nozzle flow passage between the nozzle mount and one surface of the nozzle plate, at least one nozzle support coupling the nozzle plate and the nozzle mount, and fixed to at least the nozzle plate by caulking, and at least one nozzle vane supported between the nozzle plate and the nozzle mount. The nozzle plate has a through hole into which an end portion of the at least one nozzle support is inserted.

Abstract: A topological rotary engine includes a first transmission mechanism, a second transmission mechanism, a valve mechanism, a rotor, and a cylinder. The rotor is arranged in an inner chamber of the cylinder. A cross section of the rotor is a curved-side topological polygon having n sides. A cross section of the inner chamber of cylinder is a curved-side topological polygon having n+1 sides, and n is an even number greater than or equal to 4. An outer topological curved surface of the rotor is meshed with an inner topological curved surface of the cylinder. The rotor reversely revolves around an axis of the cylinder with an eccentricity as a radius while rotating, and divides the cylinder into n+1 independent chambers. The cylinder is provided with n+1 fuel injection nozzles and n+1 spark plugs, which cooperate with the rotor and the valve mechanism.

Abstract: A shroud includes a first shroud that covers a first side face to which a muffler is adjacent among four side faces that an engine has, a second shroud that covers a second side face adjacent to the first side face and a third side face, and a third shroud that sections a muffler space for housing the muffler with the first shroud, the first shroud and the second shroud form an upstream side air guide path that makes cooling air flow around the engine, and the muffler space is connected to a downstream side of the upstream side air guide path.

Abstract: A vehicle and a control method are capable of generating compressed air using a motor of a hybrid vehicle so as to perform cleaning/care of the hybrid vehicle, without an additional or separate device. The vehicle includes an engine including an intake pipe provided to suck outside air and an exhaust pipe provided to discharge inside air, an opening degree control valve provided at a rear end of the exhaust pipe, and a motor configured to generate power for driving a wheel and configured to drive a piston of the engine by using a portion of the power. In response to the opening degree control valve being in a closed state, and in response to the engine being in a non-combustion state, compressed air is generated in the exhaust pipe by driving the piston of the engine with the power of the motor.

Abstract: A gas turbine engine includes a fan that has fan blades wherein the fan delivers airflow to a bypass duct. A gearbox is defined along an engine axis. A low spool is arranged aft of the gearbox and coupled to drive the gearbox. A front center body assembly is defined around the engine axis. A flexible support supports the gearbox relative to the front center body assembly. A bearing package is mounted to the front center body assembly and the low spool. A front wall is mounted to the front center body assembly. The front wall is removable from the front center body assembly to access at least one of the gearbox or the bearing package. The low spool includes a low pressure compressor hub that provides a spline for engaging the bearing package.

Abstract: A gas turbine engine includes: a main passage through which compressed air extracted from a compressor is guided to a bearing; and an oil supply device that includes an oil tank storing oil and supplies the oil to the main passage through which the compressed air flows to generate oil mist. The oil supply device includes: a pressure reducer disposed at the main passage; a bypass passage that bypasses the pressure reducer and connects an upstream passage and a downstream passage; a holding chamber disposed at the bypass passage and having a predetermined volume; a switching mechanism that permits or blocks communication between the holding chamber and the oil tank, communication between the holding chamber and the upstream passage, and communication between the holding chamber and the downstream passage; and a controller that controls the switching mechanism.

Abstract: An electroformed heat exchanger suitable for use between rotating blades and seals in a stationary casing of a turbine engine. The heat exchanger comprising a non-electroformed carrier plate having a radial outer surface and a radial outer surface, an electroformed duct provided along the radial outer surface, an electroformed rail provided on the radial inner surface, and an electroformed stiffener formed by a portion of the electroformed duct and the electroformed rail.

Abstract: A fuel pump assembly for a gas turbine engine includes a shaft for transmitting motion, a gear connected to and coaxial with the shaft with the gear having a first wear surface, a first bearing coaxial with the shaft with the first bearing being configured to support the gear and having a second wear surface positioned to interact with the first wear surface, and a plurality of indents. The indents are distributed in the first wear surface or the second wear surface and at least two of the plurality of indents are partially aligned in a radial direction.

Abstract: A multipoint fuel injection system comprises an injection system segment including a circumferentially extending outer support defining a fuel manifold with a plurality of manifold passages extending circumferentially therethrough. A first connector is included at a first circumferential end of the outer support and a second connector is included at a second circumferential end of the outer support opposite the first circumferential end. The first and second connectors are each configured to connect each manifold passage with a manifold passages of a respective outer support of a circumferentially adjacent injection system segment. The system includes a circumferentially extending inner support and a plurality of circumferentially spaced apart feed arms extending radially between the inner support and the outer support. A plurality of outlet openings extend in an axial direction from each feed arm for feeding respective injection nozzles.

Abstract: A flow metering system includes a pump configured to urge a fluid flow from a fluid source, and a recirculation line located at the pump. A pressure regulating valve is located along the recirculating line. One or more fluid delivery lines extend downstream of the pump to deliver the fluid flow to one or more fluid consumers. A flow control valve is located along each fluid delivery line of the one or more fluid delivery lines. A system controller is operably connected to the pressure regulating valve and the one or more flow control valves. The system controller is configured to maintain a selected delta pressure and a selected flow rate of the fluid flow by operation of the pressure regulating valve and the one or more flow control valves.

Abstract: Engine bleed air power recovery systems and related methods are disclosed. An example power recovery system for an aircraft engine includes a power recovery turbine coupled to aa shaft-driven device. A bleed air valve coupled between the power recovery turbine and a bleed air source. A controller configured to operate the bleed air valve to allow bleed air to flow to the power recovery turbine when the aircraft engine operates in a predetermined mode of operation.

Abstract: A turbomachine dual spool transmission system can include a transmission assembly configured to connect to a combination output of a dual spool differential at a transmission input to be driven by the combination output to turn a transmission output. The transmission assembly can be configured to provide a first output gear ratio in a first state and a second output gear ratio in a second state. The system can include the dual spool differential. The dual spool differential can include a gear assembly configured to combine a low pressure spool input and a high pressure spool input into a combination output to provide an output speed range smaller than a low pressure speed range alone.

Abstract: A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.

Abstract: In general, techniques are described by which to provide a turbine engine compressor particulate offtake. A gas turbine engine comprising a compressor may perform the techniques. The compressor may comprise a plurality of compressor stages, where each compressor stage comprises a circumferential row of stator vanes and a rotor. The compressor may also include an outer circumferential casing that defines a fluidic opening within or between adjacent compressor stages. The fluidic opening may be configured to receive particulate flowing and air through the compressor and output the particulate and air outside of the gas turbine engine. The gas turbine engine also includes a combustor in series flow downstream of the compressor, and a turbine in series flow downstream of the combustor.

Abstract: Systems and methods for operating an engine are described herein. The engine is operated at low power by supplying fuel to a combustor through a first set of fuel nozzles of at least one first manifold and without supplying fuel to the combustor through a second set of fuel nozzles of at least one second manifold. An amount of fuel to at least in part fill the at least one second manifold to impede fuel coking of the second set of fuel nozzles is determined. The amount of fuel is periodically supplied to the at least one second manifold.

Abstract: A dual pump fuel delivery system for an aircraft includes a fixed displacement fuel pump including an inlet and an outlet. The fixed displacement fuel pump is configured to supply a first portion of a fuel demand for the aircraft. A variable displacement fuel pump including an inlet portion and an outlet portion includes a selectively adjustable pump actuator configured to supply a second portion of the fuel demand. The second portion is variable. A fuel demand sensor operates to detect a selected fuel demand. A control member is operatively connected to the fuel demand sensor and the variable displacement fuel pump. The control member being configured to operate to adjust the variable displacement fuel pump to output the second portion of the fuel demand to satisfy the selected fuel demand.

Abstract: A method for detecting blowout precursors in at least one gas turbine combustor comprising: receiving combustion dynamics acoustic data measured by an acoustic measuring device associated with the combustor in real time; performing wavelet analysis on the acoustic data using simplified Mexican Hat wavelet transform analysis; and determining the existence of a blowout precursor based at least in part on the wavelet analysis. Provided also is a system and a non-transitory computer readable medium configured to perform the method.

Abstract: An internal combustion engine (1) for a vehicle is equipped with a variable compression ratio mechanism (2) capable of changing the mechanical compression ratio. An idle stop, which is for automatically stopping the internal combustion engine (1) when the vehicle stops, and a sailing stop, which is for stopping the internal combustion engine (1) in conjunction with the release of a forward clutch (8) during inertial travel, are carried out. A target compression ratio during normal travel is set on the basis of the load and rotation speed of the internal combustion engine (1). During an idle stop the target compression ratio is set to an idle stop restart compression ratio (?is). During a sailing stop the target compression ratio is set to a sailing stop restart compression ratio (?ss). The sailing stop restart compression ratio (?ss) is lower than the idle stop restart compression ratio (?is).

Abstract: An engine system includes an engine having a combustion chamber, an intake gas passage through which air to be supplied to the combustion chamber flows, an exhaust gas passage through which exhaust gas generated from the combustion chamber flows, a reformer configured to reform the fuel to generate a reformed gas containing hydrogen, a gas supply passage through which air to be supplied to the reformer flows, a bypass passage connected to the gas supply passage and the exhaust gas passage so as to bypass the reformer and through which the fuel having passed through the reformer is circulated to an upstream of the reformer, and a switching valve switched between a normal position that does not allow the fuel having passed through the reformer to flow to the bypass passage and a circulating position that allows the fuel having passed through the reformer to flow to the bypass passage.

Abstract: A variety of methods and arrangements are described for determining a pilot injection mass during skip fire operation of an internal combustion engine.

Abstract: A piston may include a splitting internal cooling runner, an end portion recessed inward to form a combustion chamber, and an annular internal cooling runner at least partially surrounding the combustion chamber. A wall of the annular internal cooling runner may partially protrude in a direction away from the end portion to form an annular splitting portion which divides the annular internal cooling runner into an outer half cavity and an inner half cavity.

Abstract: In a convergent-divergent flap pair for a turbojet engine nozzle of the variable-geometry convergent-divergent type, the convergent flap and the divergent flap include respective cooling-air ducts connected to one another through air passage openings formed in respective contact surfaces of the convergent flap and of the divergent flap arranged facing one another.

Abstract: A variable area nozzle assembly includes a fixed structure surrounding an exhaust duct extending along a nozzle axis. The fixed structure defines an exhaust duct outlet of the exhaust duct. The fixed structure includes a first side beam and a second side beam. Each of the first side beam and the second side beam extend in a direction axially aft from the exhaust duct outlet. Each of an upper thrust reverser door and a lower thrust reverser door are pivotably mounted to the first side beam and the second side beam at a first axial position. An upper panel and a lower panel are pivotably mounted to the upper thrust reverser door and the lower thrust reverser door, respectively, at a second axial position located axially forward of the first axial position. The upper panel and the lower panel define a nozzle outlet cross-sectional area therebetween.

Abstract: Disclosed are laminates comprising a carbon fiber reinforced polymer sheet and a layer of polysilazane and methods for producing such laminates.

Abstract: In a method for operating an engine, a request for an increase in thrust generated by the engine is received. In response to receipt of the request, a determination is made as to whether at least one operating condition for heat application-based thrust is met. If so, a heat source is applied to heat bypass air flowing through the bypass duct towards the exhaust nozzle and the increase in thrust is generated from an increased temperature of mixed bypass air and core air at the exhaust nozzle.

Abstract: A multi-function fuel delivery system and method of providing fuel delivery is provided that addresses space-related and cost related challenges as well as other challenges by combining a noise attenuating function, a hydrogen heating function, and a fuel supply rail capable of supplying hydrogen to multiple injectors within a single volume where a heat-transfer core utilizes an existing available internal volume of an attenuating volume or a fuel rail of a hydrogen supply manifold. A hydrogen fuel manifold, a hydrogen heat exchanger, and a fuel rail are housed in a single chamber such that a hydrogen fuel heating/cooling function, a hydrogen fuel noise/vibration attenuating function, providing the heat to the heat-transfer core, and providing the noise-attenuated H2 are performed in the single chamber.

Abstract: An internal combustion engine for use with hydrogen fuel, the engine having at least one cylinder assembly which includes a combustion chamber having a cylinder, a cylinder head and a reciprocating piston assembly, the cylinder defining a cylinder longitudinal axis; a fuel injector for injecting fuel into the combustion chamber, the fuel injector defining an injector longitudinal axis; and a fuel flow director, wherein the fuel flow director is located in the fuel flow path between an outlet of the fuel injector and the combustion chamber. The fuel injector is oriented such that the injector longitudinal axis extends at a first angle; and the fuel flow director is configured to direct fuel flow into the combustion chamber at a second angle, different to the first angle.

Abstract: A control flap (1) has a flap body (2) and a circumferential seal (3) capable of sealing upon abutting to a sealing surface (7) of an opening (8). The flap body (2) and the seal (3) are made of elastomers. The seal (3) is joined to the flap body (2) by a pressure plate (4) made of a thermoplastic. The control flap may be made by a method that includes: producing the flap body (2) from a thermoplastic by injection molding; producing the pressure plate (4) from a thermoplastic by injection molding; producing the seal (3) from an elastomer by injection molding; introducing the pressure plate (4) into the undercut (10) of the seal (3); inserting the pressure plate (4) with the seal (3) into the recess (16) of the flap body (2) and bonding the pressure plate (4) and flap body (2).

Abstract: A fuel-efficient and fuel-saving device is provided and includes a first fuel-modification device, an air-refining device, and a tubing-type fuel-modification device. The first fuel-modification device is arranged in a fuel tank. The air-refining device is arranged under a filter screen of an air filter of an internal combustion engine, and the tubing-type fuel-modification device is arranged above a pipeline between the internal combustion engine and the fuel tank. The first fuel-modification device includes a first metal box body and a plurality of nano far-infrared ceramic particles. The surface of the first metal box body has a plurality of uniformly arranged air holes. The plurality of nano far-infrared ceramic particles is arranged in the first metal box body. The ball diameter of the nano far-infrared ceramic particles is larger than the diameter of the air holes.

Abstract: A fuel feed unit has a base body with an intake channel section, into which a fuel opening opens. A partition wall section divides the intake channel section into a mixture channel and an air channel. The wall section has a recess in which the throttle flap at least partially lies in an end position. The wall section has, upstream of the recess, a continuous surface facing the mixture channel and which has lateral sections adjacent to the channel wall and a middle section running between the lateral sections. The lateral sections have, upstream of the throttle flap, a separation edge for the flow. In the end position, the side of the throttle flap facing the mixture channel defines a reference plane which divides the unit into a first region and a second region. The lateral sections extend, at least directly upstream of the recess, into the second region.

Abstract: Systems, methods, and a kit of two diverter blocks are provided for diverting a fluid from a fluid line and directing the fluid through a sensor. Fluid flows into a first a first diverter block and into a sensor before flowing out of the sensor and into a second diverter block, then into a downstream fluid line.

Abstract: The present disclosure provides a high-pressure common rail fuel injector capable of achieving highly stable injection based on the throttling damping-accommodating effect in the present disclosure, comprising a fuel injector housing, a fuel pipe connector, an accumulator chamber, a fuel chamber control valve, a pressure fluctuation absorption assembly, a control valve assembly and a nozzle assembly; the accumulator chamber is installed in the fuel injector housing, and the fuel pipe connector is installed above the accumulator chamber; the fuel chamber control valve, the pressure fluctuation absorption assembly and the control valve assembly are installed in the fuel injector housing, and the nozzle assembly is arranged below the control valve assembly; and the accumulator chamber is separated into a main accumulator chamber, an auxiliary accumulator chamber and a fuel-return accumulator chamber.

Abstract: Provided is a fuel supply pump capable of improving welding quality while securing a function of a valve body. A fuel supply pump of the present invention includes a regulating member (discharge valve stopper 84) that guides movement of a valve body (discharge valve 82), a main body portion (body 1) provided with a valve chamber (discharge valve chamber 1d) that houses the regulating member, a sealing member (plug 85) that seals the valve chamber, and a welded portion (welded portion 86) that fixes the sealing member to the main body portion. An annular space portion (annular space portion 60) along an outer periphery of the regulating member is formed between the welded portion and the regulating member.

Abstract: An alignment device for a ducted fuel injection system comprising a mounting block removably attachable to a duct of the ducted fuel injection system. The mounting block can include a passageway extending therethrough. The passageway can align with the duct when the mounting block is attached to the duct. The alignment device further comprises an imaging device configured to capture an image viewing through the duct toward an outlet of a fuel injector. A portion of the imaging device can extend in the passageway. The alignment device additionally comprises a centering structure configured to align a portion of the imaging device with a central axis of the duct. The image captured by the imaging device can be configured for use aligning a position of an outlet of a fuel injector with respect to a position of the duct.

Abstract: A hydro-kinetic power generation system is disclosed. The system includes a structure to be positioned in shallow or deep waterways, such as canals and rivers. The structure may be modular, such that the structure may be composed of one or more structural units that are each substantially the same. In various embodiments, each unit includes one or more curved walls for accelerating water through the unit, or through the structure as a whole. In one embodiment, the accelerator walls are curved for optimizing water flow through the structure without generating undue head loss. In certain embodiments, the units may be configured such that the accelerator walls are positioned on opposite sides of the structure, or the accelerator walls may be adjacently positioned. Coupled to the structure are turbines and gear box systems for harnessing energy from the moving water and converting the energy into electric power.

Abstract: A composite material blank comprising an elongate blank body extending between a first end face and a second end face; said blank body extending in a longitudinal direction, parallel to a longitudinal axis thereof, and having four peripheral sides; each said first and second end face having edges which define a trapezoid shape; wherein the peripheral sides of said blank body connect the edges of said first end face with the edges of said second end face; and wherein said first trapezoid end face is inverted in relation to said second trapezoid end face. A method of manufacturing a composite blank, and a wind turbine blade root insert which may be formed from a blank.

Abstract: Provided is an arrangement for removing and/or exchanging a hydraulic fluid accumulator installed within a hub of a wind turbine, the arrangement including: a first pair of mounting legs each having at an upper portion connector for connecting to a hub component; a second pair of mounting legs each having at an upper portion connector for connecting to a hub component; a first bar connecting the first pair of mounting legs at a lower portion; a second bar connecting the second pair of mounting legs at a lower portion; an elongate resting structure for carrying an accumulator, the resting structure being at one end slidably supported by the first bar and at another end slidably supported by the second bar and being movable in a parallel manner traverse, in particular perpendicular, to a longitudinal direction the resting structure.

Abstract: A system for and a method of frequency control of a variable-speed wind power generator are proposed. According to an implementation example of the present technology, there is an advantage in which the present technology may be involved in a frequency control of the system, thereby stabilizing the frequency of the system by controlling the frequency of the variable-speed wind power generator on the basis of a gain being varied according to a speed of a rotor.