Anders G Andersson

US Patent:

42480930, Feb 3, 1981

Filed:

Apr 13, 1979

Appl. No.:

6/029632

Inventors:

Anders O. Andersson - Seattle WA
Robert B. Purves - Kent WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

G03H 300

US Classification:

73656

Abstract:

A system for determining the spatial structure or composition of complex sound fields within a duct or other structural enclosure that is excited by acoustic energy is disclosed wherein at least two holograms are recorded and analyzed to provide both the amplitude and phase of the various modal components that comprise the sound field. In situations in which the sound field of interest is periodic, the desired amplitude and phase information is determined from a pair of holograms in which each hologram is formed by photographically recording the diffraction pattern resulting when an array of elastomeric regions, positioned on the wall of the acoustically excited structure, is illuminated by two pulses of coherent monochromatic light that are spaced apart in time by nT/2, where T is the period of the dominant acoustic excitation signal and n is an odd integer. In situations in which the sound field is aperiodic, the elastomeric array is sequentially illuminated by a series of monochromatic light pulses with the reflected energy of each pulse being utilized to form separate holographic records. The holographic records resulting from consecutive pulses are then combined to form a number of interferograms.

US Patent:

46515666, Mar 24, 1987

Filed:

Apr 28, 1986

Appl. No.:

6/856705

Inventors:

Anders O. Andersson - Seattle WA
David R. Slotboom - Mercer Island WA
Paul C. Topness - Renton WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

G01N 2904

US Classification:

73589

Abstract:

A portable acoustic impedance measuring device 10 is provided for measuring the impedance properties of a panel 12. The device 10 includes a horn section 14 having a flexible plate 18. The plate 18 can assume the curvature of the duct panel 12. The horn section 14 is supported adjacent the panel's surface by a spindle shaft 28 which spans or bridges the inside diameter of the duct 12. The curvature of the plate 18 may be locked to hold the curvature of any of a variety of different panels having various sizes and shapes.

US Patent:

41226747, Oct 31, 1978

Filed:

Dec 27, 1976

Appl. No.:

5/754584

Inventors:

Anders O. Andersson - Seattle WA
Robert B. Purves - Kent WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

F02C 724

US Classification:

60 3965

Abstract:

A burner can, including a noise suppressing cavity, for use in the combustor assembly of a gas turbine engine to minimize the combustion noise emitted by the engine, is disclosed. The cavity is mounted at an end of the burner can that includes a fuel nozzle for injection of fuel into the interior of the burner can and is in acoustic communication with the interior of the burner can via a perforated metal sheet that forms a partition between the burner can and the cavity. The cavity is dimensioned and arranged in view of the acoustic transmission system formed by the burner can and the duct system that interconnects the burner can with the engine turbine stage to exhibit an acoustic impedance which minimizes the propagation of combustion noise from the burner can through the engine turbine stages to thereby reduce the engine noise level.

US Patent:

56927029, Dec 2, 1997

Filed:

Apr 30, 1996

Appl. No.:

8/641293

Inventors:

Anders O. Andersson - Seattle WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

F01D 2504

US Classification:

244 1N

Abstract:

The application of active noise control to influence the fan-noise components in engine ducts. The fan is used as a source of counter noise by introducing flow distortions upstream or downstream of the fan. Microphone arrays sense the noise and produce a control output signal for controlling a distortion producer. The control output signal for the distortion producer comes from a control algorithm utilizing the output of the microphone signals sampled at a defined rate based on the fan blade passing frequency.

US Patent:

60091800, Dec 28, 1999

Filed:

Sep 17, 1996

Appl. No.:

8/710352

Inventors:

Anders O. Andersson - Seattle WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

A61F 1106

US Classification:

381 714

Abstract:

Fluidic constructs, including grouped stacks of fluidic elements, that provide countersound to control sound in a noisy environment, prevent radiation of sound from vibrating surfaces, reduce sound-induced vibration of surfaces, and absorb sound that might otherwise impact on surfaces, are provided. These constructs may have a wide range of geometries for specific applications, but generally include a face plate on one side, and a back plate on the other side. Supply ports on the back plate provide a supply of fluid that flows through the construct, while undergoing acoustic modulation through fluidic amplifiers. The face plate includes input ports that sense sound waves to be controlled, and transmits this sound to influence the acoustic modulation of the supplied fluid. The construct produces an amplified output, having sound out of phase with the sound sensed by the input ports, at output ports on the face plate in a sufficient volume to substantially neutralize incoming sound waves, or reduce sound radiation from an object. Any sound produced by the construct of the invention that is substantially in phase with sound to be neutralized is dumped at a sufficient distance from the produced countersound to minimize interference.

US Patent:

51970104, Mar 23, 1993

Filed:

Dec 13, 1990

Appl. No.:

7/626977

Inventors:

Anders O. Andersson - Seattle WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

G01M 138

US Classification:

364463

Abstract:

Apparatus for continuously actively balancing rotors by controlling the mass-distribution of a rotor (24) relative to an axis-of-rotation (27) about which the rotor rotates in a stator (26) is disclosed. The mass-distribution of the rotor is adjustable via a hydraulic subsystem (23) that can move the rotor relative to the axis-of-rotation. An electronic subsystem (22) controls the hydraulic subsystem (23) with control signals. More specifically, the sensors (100) of a sensor subsystem (21) sense the repetitive vibrations caused by an unbalanced rotot. The electronic subsystem (22) cyclically updates the control signals applied to the hydraulic subsystem (23) so as to reduce the sensed vibrations, i. e. , to balance the rotor (24). The hydraulic subsystem (23) adjusts the position of the rotor (24) by varying the flow of a viscous fluid between the perimeter of a portion of the rotor (24) and an annular sleeve (34) encompassing that portion of the rotor.

US Patent:

41447689, Mar 20, 1979

Filed:

Jan 3, 1978

Appl. No.:

5/866390

Inventors:

Anders O. Andersson - Seattle WA
Robert B. Purves - Kent WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

G01N 2902

US Classification:

73646

Abstract:

A system for resolving a complex acoustic field, resulting when acoustic energy propagates through a duct, into component unit spatial pressure patterns or modes is disclosed. In each disclosed system arrangement, an acoustic filter, which includes one or more annular cavities, circumferentially surrounds the duct through which the acoustic energy propagates and sound is coupled from the duct into one end of each annular filter cavity via a series of openings which exhibit a relatively high acoustic impedance and a relatively high resistance to fluid flow. Each filter cavity is dimensioned such that it is excited into resonance when the circumferential distance between adjacent nodes of a modal component of the pressure pattern within the duct is mathematically related to the velocity of sound within a filter cavity by a predetermined factor. When a cavity resonates, maximum acoustic pressure transfer occurs between the duct and two or more microphones that are circumferentially spaced apart from one another along the second end of each annular filter cavity. A gas mixture is introduced into the annular cavities to control the velocity of sound within the cavities and the composition of the gas is controlled such that cavity resonance occurs at each pressure mode of interest.

US Patent:

50497685, Sep 17, 1991

Filed:

Dec 5, 1988

Appl. No.:

7/280054

Inventors:

Anders O. Andersson - Seattle WA

Assignee:

The Boeing Company - Seattle WA

International Classification:

F16F 1522
G05D 1702

US Classification:

310 51

Abstract:

Noise and vibration in a structure are reduced through application to the structure of an oscillatory torque. An electromechanical energy converter provides the oscillatory torque when the input signal to the electromechanical energy converter has a frequency and harmonics thereof required to counteract the noise and vibration desired to be attenuated.