Piezoelectric actuators optimized for synthetic jet actuators

Patent metadata

Field	Value
Publication number	US-9803666-B2
Application number	US-201514712510-A
Country	US
Kind code	B2
Filing date	May 14, 2015
Priority date	May 14, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A synthetic jet actuator and a method for optimizing a synthetic jet actuator to meet operating requirements and physical constraints may include estimating dimension and a resonance frequency of an air cavity of the synthetic jet actuator, and using the estimated resonance frequency to the estimate dimensions of a piezoelectric actuator of the synthetic jet actuator. Individual simulations of the air cavity and piezoelectric actuator, and a coupled simulation may be performed using the estimated dimensions, and the dimensions may be revised and simulations re-executed to match the resonance frequencies of the air chamber and the piezoelectric actuator. The method maybe yield a synthetic jet actuator having a resonance frequency of the piezoelectric actuator that is approximately equal to a quarter-wavelength resonance frequency of the air cavity.

First claim

What is claimed is:

1. A method for optimizing a synthetic jet actuator to meet operating requirements and physical constraints on a design of the synthetic jet actuator, the synthetic jet actuator having an air cavity having a cylindrical shape with a cavity diameter and a cavity height, and an orifice, the synthetic jet actuator further including a piezoelectric actuator that is actuated to alternately increase and decrease a cavity volume of the air cavity to draw air into and expel the air from the air cavity, respectively, through the orifice, the method for optimizing comprising:
calculating a resonance frequency for the air cavity based on an estimated cavity diameter for the air cavity;
performing a coupled simulation of the air cavity of the synthetic jet actuator with the piezoelectric actuator using estimated air cavity dimensions and estimated piezoelectric actuator dimensions;
comparing simulation output data from the coupled simulation of the air cavity and the piezoelectric actuator to the operating requirements for the synthetic jet actuator; and
adjusting at least one of the estimated air cavity dimensions and the estimated piezoelectric actuator dimensions in response to determining that the simulation output data from the coupled simulation does not meet at least one of the operating requirements for the synthetic jet actuator.

2. The method for optimizing a synthetic jet actuator of claim 1 , wherein calculating the resonance frequency for the air cavity comprises solving a quarter-wavelength resonance frequency equation:
f c =ν/4 d c

where f c is a quarter-wavelength resonance frequency for a tube that is closed at one end, ν is a speed of sound in a gas, and d c is the estimated cavity diameter for the air cavity.

3. The method for optimizing a synthetic jet actuator of claim 1 , wherein calculating the resonance frequency for the air cavity comprises creating a coarse finite element model of the air cavity with maximum pressure conditions at all structural boundaries and minimum pressure conditions at all orifices.

4. The method for optimizing a synthetic jet actuator of claim 1 , comprising performing a structural simulation of the piezoelectric actuator using the estimated piezoelectric actuator dimensions and performing a fluid and acoustic simulation of the air cavity of the synthetic jet actuator using the estimated air cavity dimensions before performing the coupled simulation of the air cavity of the synthetic jet actuator with the piezoelectric actuator.

5. The method for optimizing a synthetic jet actuator of claim 1 ,
wherein comparing the simulation output data from the coupled simulation to the operating requirements for the synthetic jet actuator comprises comparing a simulation maximum output momentum of air output through the orifice from the coupled simulation is at least equal to a required maximum output momentum of the operating requirements;
wherein adjusting at least one of the estimated air cavity dimensions and the estimated piezoelectric actuator dimensions comprises adjusting at least one of an orifice length, an orifice width and an orifice neck length of the orifice to increase the simulation maximum output momentum in response to determining that the simulation maximum output momentum is less than the required maximum output momentum; and
wherein the method for optimizing comprises re-performing the coupled simulation of the air cavity of the synthetic jet actuator with the piezoelectric actuator after adjusting at least one of the orifice length, the orifice width and the orifice neck length.

6. The method for optimizing a synthetic jet actuator of claim 5 , comprising:
determining whether at least one of the orifice length, the orifice width and the orifice neck length may be adjusted to increase the simulation maximum output momentum, wherein adjusting at least one of the estimated air cavity dimensions and the estimated piezoelectric actuator dimensions comprises adjusting the cavity diameter of the air cavity to increase the simulation maximum output momentum in response to determining that the orifice length, the orifice width and the orifice neck length may not be adjusted to increase the simulation maximum output momentum; and
recalculation the resonance frequency after adjusting the cavity diameter of the air cavity in response to determining that the orifice length, the orifice width and the orifice neck length may not be adjusted to increase the simulation maximum output momentum.

7. The method for optimizing a synthetic jet actuator of claim 1 ,
wherein adjusting at least one of the estimated air cavity dimensions and the estimated piezoelectric actuator dimensions comprises adjusting a piezoelectric disk thickness of the piezoelectric actuator in response to determining that a simulation synthetic jet actuator output pressure is less than a required synthetic jet actuator output pressure or that a piezoelectric actuator resonance frequency is not equal to the resonance frequency for the air cavity; and
wherein the method for optimizing comprises recalculating the estimated piezoelectric actuator dimensions and re-performing the coupled simulation of the air cavity of the synthetic jet actuator with the piezoelectric actuator after adjusting the piezoelectric disk thickness.

8. The method for optimizing a synthetic jet actuator of claim 1 , comprising setting a piezoelectric disk diameter of a piezoelectric disk of the piezoelectric actuator equal to a value within a range of 75% to 90% of the cavity diameter of the air cavity.

9. A method for optimizing a synthetic jet actuator having an air cavity having a cylindrical shape with a cavity diameter and a cavity height, and an orifice, the synthetic jet actuator further including a piezoelectric actuator that is actuated to alternately increase and decrease a cavity volume of the air cavity to draw air into and expel the air from the air cavity, respectively, through the orifice, the method for optimizing comprising:
determining operating requirements for the synthetic jet actuator;
determining physical constraints on a design of the synthetic jet actuator based on an operating environment for the synthetic jet actuator;
determining estimated synthetic jet actuator dimensions for the synthetic jet actuator based on the operating requirements and the physical constraints;
calculating a resonance frequency for the air cavity based on an estimated cavity diameter for the air cavity;
calculating estimated piezoelectric actuator dimensions for the piezoelectric actuator based on the estimated synthetic jet actuator dimensions and the resonance frequency;
performing simulations of the air cavity of the synthetic jet actuator and the piezoelectric actuator using the estimated synthetic jet actuator dimensions and estimated piezoelectric actuator dimensions;
comparing simulation output data from the simulations of the air cavity and the piezoelectric actuator to the operating requirements for the synthetic jet actuator; and
adjusting at least one of the estimated synthetic jet actuator dimensions and the estimated piezoelectric actuator dimensions in response to determining that the simulation output data from the simulations does not meet at least one of the operating requirements for the synthetic jet actuator.

10. The method for optimizing a synthetic jet actuator of claim 9 , wherein calculating the resonance frequency for the air cavity comprises solving a quarter-wavelength resonance frequency equation:
f c =ν/4 d c

where f c is a quarter-wavelength resonance frequency for a tube that is closed at one end, ν is a speed of sound in a gas, and d c is the estimat

Assignees

• Boeing Co

Inventors

• Whalen Edward A
• Griffin Steven F
• Van Schoor Marthinus Cornelius
• Clery Conor

Classifications

• F04B39/00

  Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00 · CPC title

• F04B45/047 Primary

  Pumps having electric drive · CPC title

• F04B43/046

  with piezoelectric drive · CPC title

• H01L41/22

  Electricity · mapped topic

• F15D1/008 Primary

  comprising fluid injection or suction means · CPC title