Mechanical transducers: Cantilevers, acoustic wave sensors, and thermal sensors

Zhang, John X. J.; Hoshino, Kazunori

doi:10.1016/b978-0-12-814862-4.00006-5

Cited by 26 publications

(13 citation statements)

References 122 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another interesting topic to discuss is the damping ratio. According to half-band power criteria (Zhang and Hoshino, 2019), the non-dimensional damping ratio (ξ) can be estimated using the frequency spectrum of a resonance. To calculate this, first the frequency band in which the half of the power is accumulated is found.…”

Section: Resultsmentioning

confidence: 99%

Sensitivity analysis on the impact of geometrical and operational variations on turbine hub cavity modes and practical methods to control them

Iranidokht

Kalfas

Abhari

et al. 2021

J. Glob. Power Propuls. Soc.

View full text Add to dashboard Cite

This paper presents an experimental investigation on the impact of different design and operational variations on the instabilities induced at the hub cavity outlet of a turbine. The experiments were conducted at the “LISA” test facility at ETH Zurich. The axial gap at the 2nd stage hub cavity exit was varied, and also three different flow deflectors were implemented at the cavity exit to control the cavity modes (CMs). Furthermore, the turbine pressure ratio was altered to mimic the off-design condition and study the sensitivity of the CMs to this parameter. Measurements were performed using pneumatic, and Fast Response Aerodynamic Probes (FRAP) at stator and rotor exit. In addition, unsteady pressure transducers were installed at the cavity exit wall to measure the characteristic parameters of the CMs. For the small axial gap, distinct and strong CMs were generated, which actively interacted with stator and rotor hub flow structures. Increasing the gap damped the fluctuations; however, a broader range of frequencies was amplified. The flow deflectors successfully suppressed the CMs by manipulating the shear layer velocity profile and blocking the growing instabilities. Eventually, the increase in the turbine pressure ratio strengthened the CMs and vice versa.

show abstract

Section: Resultsmentioning

confidence: 99%

Sensitivity analysis on the impact of geometrical and operational variations on turbine hub cavity modes and practical methods to control them

Iranidokht

Kalfas

Abhari

et al. 2021

J. Glob. Power Propuls. Soc.

View full text Add to dashboard Cite

show abstract

“…Another interesting topic to discuss is the damping ratio. According to half-band power criteria [16], the nondimensional damping ratio ( ) can be estimated using the frequency spectrum of a resonance. To calculate this first, the frequency band in which the half of the power is accumulated is found.…”

Section: Figure 6-the Impact Of Cavity Geometry Modification On the Bmentioning

confidence: 99%

Sensitivity Analysis on the Impact of Geometrical and Operational Variations on Turbine Hub Cavity Modes and Practical Methods to Control them

Iranidokht¹,

Kalfas²,

Abhari³

et al. 2020

Proceedings of Global Power &Amp; Propulsion Society

View full text Add to dashboard Cite

This paper presents an experimental investigation on the impact of different design and operational variations on the instabilities induced at the hub cavity outlet of a turbine. The experiments were conducted at the "LISA" test facility at ETH Zurich. The axial gap at the 2 nd stage hub cavity exit was varied, and also three different flow deflectors were implemented at the cavity exit to control the cavity modes (CMs). Furthermore, the turbine pressure ratio was altered to mimic the off-design condition and study the sensitivity of the CMs to this parameter. Measurements were performed using pneumatic, and Fast Response Aerodynamic Probes (FRAP) at stator and rotor exit. In addition, unsteady pressure transducers were installed at the cavity exit wall to measure the characteristic parameters of the CMs. For the small axial gap, distinct and strong CMs were generated, which actively interacted with stator and rotor hub flow structures. Increasing the gap damped the fluctuations; however, a broader range of frequencies was amplified. The flow deflectors successfully suppressed the CMs by manipulating the shear layer velocity profile and blocking the growing instabilities. Eventually, the increase in the turbine pressure ratio strengthened the CMs and vice versa.

show abstract

“…Mechanical deformation of a piezoresistive material, emanating from applied stress or strain, causes transduction of the mechanical force into a change in piezoresistivity and material conductivity, known as the piezoresistive effect . The performance of a piezoresistive material as a wearable strain sensor is based on certain criteria, including low hysteresis, high sensitivity, compressibility, and electromechanical stability under repeated dynamic loading conditions. , Piezoresistive materials can also be used within pressure sensors, which have applications in detection of subtle pressures such as blood flow or “touch” in the context of, for example, brain machine interfaces …”

Section: Introductionmentioning

confidence: 99%

Beyond Chemistry: Tailoring Stiffness and Microarchitecture to Engineer Highly Sensitive Biphasic Elastomeric Piezoresistive Sensors

Solazzo

Hartzell

O'Farrell

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Carbon-based nanoparticles and conductive polymers are two classes of materials widely used in the production of three-dimensional (3D) piezoresistive sensors. One conductive polymer, poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) has excellent stability and conductivity yet is limited in its application as a sensor, often existing upon a base, limiting its performance and potential. Despite much progress in the field of materials chemistry and polymer synthesis, one aspect we consider worthy of exploration is the impact that microstructure and stiffness may have on the sensitivity of 3D sensors. In this study, we report a strategy for fabricating biphasic electroactive sponges (EAS) that combine 3D porous PEDOT:PSS scaffolds possessing either an isotropic or anisotropic microarchitecture, infused with insulating elastomeric fillers of varying stiffness. When characterizing the electromechanical behavior of these EAS, a higher stiffness yields a higher strain gauge factor, with values as high as 387 for an isotropic microarchitecture infused with a stiff elastomer. The approach we describe is cost-effective and extremely versatile, by which one can fabricate piezoresistive sensors with adaptable sensitivity ranges and excellent high strain gauge factor with the underlying microarchitecture and insulant stiffness dictating this performance.

show abstract

Mechanical transducers: Cantilevers, acoustic wave sensors, and thermal sensors

Cited by 26 publications

References 122 publications

Sensitivity analysis on the impact of geometrical and operational variations on turbine hub cavity modes and practical methods to control them

Sensitivity analysis on the impact of geometrical and operational variations on turbine hub cavity modes and practical methods to control them

Sensitivity Analysis on the Impact of Geometrical and Operational Variations on Turbine Hub Cavity Modes and Practical Methods to Control them

Beyond Chemistry: Tailoring Stiffness and Microarchitecture to Engineer Highly Sensitive Biphasic Elastomeric Piezoresistive Sensors

Contact Info

Product

Resources

About