408 results about "Fan noise" patented technology

An engine nacelle inlet lip includes both acoustic treatment and electric heating for ice protection. The inlet lip has a composite outer skin and a composite inner skin, with the composite outer skin having at least one integrated heater element embedded in the composite material. An acoustic cellular core positioned between the outer and inner skin acts to attenuate fan noise from the engine. Covering the outer skin and overlying the acoustic core is a perforated erosion shield having a first set of openings that pass entirely thorough its thickness. The composite outer skin includes a second set of openings such that sound waves can pass from an inner barrel portion of the inlet lip through the erosion shield, outer skin, and heater element to the underlying acoustic cellular core.

A hearing compensation system comprises a plurality of bandpass filters having an input connected to an input transducer and each bandpass filter having an output connected to the input of one of a plurality of multiplicative automatic gain control (MAGC) circuits whose outputs are summed together and connected to the input of an output transducer. The MAGC circuits attenuate acoustic signals having a constant background level without the loss of speech intelligibility. The identification of the background noise portion of the acoustic signal is made by the constancy of the envelope of the input signal in each of the several frequency bands. The background noise that will be suppressed includes multi-talker speech babble, fan noise, feedback whistle, florescent light hum, and white noise. For use in the consumer electronics field background acoustic noise may be sensed and used to adjust gain in the various MAGC circuits so as to improve a user's listening experience, whether the user is hearing impaired or not.

A centrifugal fan with low noise includes a housing, a fan wheel and a recess unit. The fan wheel has a hub and a plurality of fan blade extending outward from the hub radially. The housing has a chamber therein to receive the fan wheel and has a recess unit at the surface thereof. The recess unit is composed of a projection part and a recess part for reducing noise transmission greatly.

One embodiment of the present invention provides a system that cancels fan noise in a computer system. During operation, the system obtains a fan noise signal using a microphone. Next, the system generates a spectral pattern based on the obtained fan noise signal. The system then uses the spectral pattern to identify a corresponding cancellation spectrum in an anti-spectra library. Next, the system generates a noise-canceling signal using the cancellation spectrum. Note that the amount of computation required to cancel fan noise is reduced because generating the noise-canceling signal using the anti-spectra library requires less computation than generating the noise-canceling signal using dynamic noise-cancellation techniques.

A portable computer includes a motion detector providing input signals used for detecting movements indicating that the computer is held on the users lap or in his hands instead of on a desktop. When such movements are detected, the computer is operated in a first mode, with temperatures within the computer being controlled to maintain a surface of the housing at a temperature that is comfortable for the user. Otherwise, temperatures within the computer are allowed to rise to provide for faster processing or less fan noise.

A fan system, such as a turbofan, marine propeller, or a cooling fan, includes a fan noise control system for reducing noise generated by the fan system. The noise control system may be configured to reduce either broadband noise, blade-passage noise, or both. In particular, the fan noise control system suitably includes a pre-swirl generator configured to provide a layer of fluid upstream from the fan blades. The layer swirls in the direction of the fan's rotation, reducing the angular velocity differential between the fan blades and the incident fluid. In addition, the fan noise control system may also include a fluid seal generator configured to create a fluid barrier between the fan blade tips and the interior surface of the fluid flow channel. The fluid seal inhibits leakage flow between the fan blade tips and the interior surface as well as the formation of blade vortices. By minimizing the blade wake and the blade tip vortices without adding solid surfaces, noise tends to diminish.

A temperature controlling apparatus determines a fan rotation speed from a surrounding noise and a fan noise, measures a temperature of a large scale integration (LSI) device or the like that is a controlled object, determines, in a cooling capacity range of the determined fan rotation speed, an operating clock frequency that falls within an allowable temperature range, and controls the LSI to be connected.

The present invention concerns a wind power installation comprising a pylon, a pod mounted rotatably on the pylon, a generator arranged within the pod and having a rotor and a stator, and at least one fan in the region of the pod. In order to reduce the entry of moisture, sand and other foreign substances into the pod and also to reduce the fan noise which reaches the exterior, in accordance with the invention there is provided an arrangement of the fan within the pod, wherein the fan sucks in outside air through a downwardly open first air gap, in particular between the pylon and the pod. In that respect the invention is based on the realization that the air flow along the wind power installation and in particular in the region of the pod has a markedly pronounced horizontal component and at best a markedly less pronounced vertical component. In other words the wind and therewith the foreign substances transported thereby flow at the windward side along the pod to the lee side and have then passed the wind power installation. If therefore air is sucked in through a downwardly open air gap, then at most very fine particles can still also be sucked in, which more specifically can be borne upwardly by the air flow, against the effect of the force of gravity. As a result the suction intake of relatively large particles of sand and dust and also the suction intake of raindrops which, as anyone knows, are considerably heavier, is reduced to a high degree, if not entirely prevented.

The invention relates to a fan structure and an axial fan, comprising a wheel hub and three blades mounted on the wheel hub, wherein the three blades are equidistantly distributed by using a rotation central axis of the blade as the centre, the blade is provided with a tail edge and a front edge opposite to the tail edge, the tail edge of the blade is provided with at least five W-shaped grooves which are gradually reduced in proportion from outside to the wheel hub direction. In the invention, the air quantity and the efficiency of the axial fan can be effectively improved, the fan vibration is improved, and the fan noise and the design cost are reduced; meanwhile, the weight of the fan is lightened, and the load of the fan motor is reduced; according to above characteristics, the axial fan is preferably suitable for an outdoor unit of an air-conditioner, and can improve the refrigerating output, heat quantity and energy efficiency ratio of the air-conditioner.

A fan system includes a rotor supported for rotation about a fan axis. The rotor has a central hub and a plurality of blades each extending outwardly from the hub to a tip. The rotor blades define a rotor plane perpendicular to the fan axis. A first acoustic resonator has an opening disposed on a first side of the rotor plane and a second acoustic resonator has an opening disposed on a second side of the rotor plane. The acoustic resonators are configured to provide a dipole resonator system operable to at least partially reduce a blade pass frequency tone in an upstream and a downstream direction simultaneously.

The invention discloses an ionic fan applied to an air-conditioner. The ionic fan applied to the air-conditioner comprises an anion generator array layer framework (1), an anion generator carbon brush head (2), an ionic fan casing (3), an insulation screen grid layer (4), insulating blankets (5), an insulating accelerating grid layer (6) and insulating screws (7), wherein the insulation screen grid layer (4) and the insulating accelerating grid layer (6) which are interlayered with the insulating blankets (5) are fixed on the ionic fan casing (3) through the insulating screws (7) to form a high concentration anion generating chamber, when hot air or cold air of air-conditioning air constantly enters the high concentration anion generating chamber, the anion generator carbon brush head (2) immediately takes 'ionization effect' on gas molecules to generate anions, the anions are constantly collected in the anion generating chamber to form high concentration anion air, and the high concentration anion air is focalized through the insulation screen grid layer (4) fed by positive high pressure and accelerated by the insulating accelerating grid layer (6) fed by negative high pressure to form high concentration anion wind with a certain speed. The ionic fan applied to air-conditioner has the advantages that a fan system of a traditional air-conditioner can be replaced, producing costs of the air-conditioner can be reduced, the inner structure of the air-conditioner can be optimized, the whole appearance of the air-conditioner can be beautified, and fan noise influence of the air-conditioner in a working state is reduced.

A system and method of spread-spectrum fan control for an air-cooled system is provided for reducing the vibrational and acoustical noise associated with the air-cooled system. The method includes generating a first control signal that controls a blade-passing frequency of a first cooling fan and a second control signal that controls a blade-passing frequency of a second cooling fan, wherein the first and second control signals may be pulse width modulated (“PWM”) signals. One or more noise generators independently vary duty cycles for the first and second PWM signals within a range around respective first and second blade-passing frequency set points. As a result, the blade-passing frequencies for the first and second cooling fans are independently and randomly modulated within a range around the respective first and second blade-passing frequency set points.

A fan system with enhanced air flow-static pressure characteristics and reduced fan noise compared to the related art is provided. The number of duct blades of a duct is the same as the number of stationary blades of an axial flow fan located in front of the duct, and the duct blades correspond to the stationary blades respectively. An end surface of a rear end portion of each stationary blade and an end surface of a front portion of a duct blade corresponding to the stationary blade have the same shape, and they align together and contact each other to form one composite stationary blade, with a discharge port of each axial flow fan communicating with an inlet port of a duct housing located behind the axial flow fan.

A free-tipped axial fan assembly has a skew distribution which reduces fan noise while minimizing radial tip deflection. The difference between the maximum value of leading-edge skew and the value of leading-edge skew at the fan radius is at least 10 degrees. The ratio of the difference of the leading-edge skew between the maximum value and the value at the fan radius to the difference of the trailing-edge skew between the maximum value and the value at the fan radius is at least 2.5.

The present invention is the fan noise controlling method via rotation speed. The method includes setting one temperature control pattern for predicting fan rotation speed, predicting fan noise and corresponding CPU temperature change, and obtaining the optimized design of the heat radiation effect and noise of the fan. The said method is superior to available try and error method, which needs great amount of man power and time in finding out proper rotation speed.

The invention relates to a fan noise eliminating system which at least comprises a loudspeaker, a sensor unit and a data signal microprocessor, wherein the data signal microprocessor is provided with a signal amplifying unit, a signal conversion unit and a combination controller, the signal amplifying unit is provided with a prime amplifier and a post amplifier, the prime amplifier is electrically connected with the sensor unit, the post amplifier is electrically connected with the loudspeaker, the signal conversion unit is provided with an analog/digital converter and a digital/analog converter, the analog/digital converter is electrically connected with the prime amplifier, the digital/analog converter is electrically connected with the post amplifier, the combination controller is electrically connected with the analog/digital converter and the digital/analog converter, therefore, noise waves generated by the fan can be mutually cancelled with reverse sound waves generated by the loudspeaker to effectively reduce noise and ensure good radiating effect.

The invention discloses a fan device achieving active noise reduction. The fan device is in the shape of a circular cavity assembly. A noise reduction device and a fan fixing structure are arranged in the circular cavity assembly. The noise reduction device comprises a noise collection unit, a noise reduction module and a noise reduction loudspeaker unit. The noise reduction module comprises an active noise reduction SOC chip and a power amplifier circuit. The noise collection unit, the active noise reduction SOC chip, the power amplifier circuit and the noise reduction loudspeaker unit are connected in sequence. A noise reduction loudspeaker fixing assembly is also arranged in the cavity of the circular cavity assembly. According to the fan device achieving active noise reduction, the noise collection unit and the noise reduction module are installed on a fan air channel, signals with phases opposite to phases of noise sources are generated by means of the active noise reduction technology, fan noise is counteracted inside the pipeline, and the fan noise is effectively lowered; in addition, the fan device has the advantages of being advanced in technology, easy and convenient to achieve, wide in application prospect and the like.