scholarly journals Experimental Measurement Benchmark for Compressible Fluidic Unsteady Jet

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 58
Author(s):  
Pablo Fernandez ◽  
Jerome Delva ◽  
Celestin Ott ◽  
Philipp Maier ◽  
Quentin Gallas
Keyword(s):  
Extreme Values ◽  
Laser Doppler Anemometry ◽  
Measurement Techniques ◽  
Synthetic Jet ◽  
Velocity Measurements ◽  
Worst Case ◽  
Synthetic Jet Actuator ◽  
Cold Wire ◽  
Measured Flow ◽  
Unsteady Jet

A benchmark of different measurement techniques is presented to characterize the dynamic response of a synthetic jet actuator working in compressible regime. The setup involves a piston-based synthetic jet, as well as the benchmarked measurements are hot-wire, cold-wire, Laser Doppler Anemometry, pressure transducer, and Schlieren visualization. Measured flow temperatures range from 20 °C to 150 °C, pressure ranges from 0.5 atm to 4 atm, and velocity are up to 300 m/s. The extreme values of these ranges are reached in an oscillating fashion at a frequency ranging from 30 to 100 Hz. The measurements are pointing out the limitation of cold-wire measurements, due to its high thermic inertia. The results show consistency in the velocity measurements, within 10% in the worst case, between all measurement techniques and the errors are traced back to the calibration ranges, whose sensitivity is also studied.

scholarly journals Cephalopod‐Inspired Swimming Robot Using Dielectric Elastomer Synthetic Jet Actuator

2020 ◽  
Vol 22 (4) ◽  
pp. 2070014
Author(s):  
Chao Tang ◽  
Wentao Ma ◽  
Bo Li ◽  
Mingliang Jin ◽  
Hualing Chen
Keyword(s):  
Dielectric Elastomer ◽  
Synthetic Jet ◽  
Synthetic Jet Actuator

Wing tip vortex control using synthetic jets

2006 ◽  
Vol 110 (1112) ◽  
pp. 673-681 ◽  
Author(s):  
P. Margaris ◽  
I. Gursul
Keyword(s):  
Synthetic Jet ◽  
Synthetic Jets ◽  
Tip Vortex ◽  
Particle Image Velocimetry System ◽  
Driving Frequency ◽  
Velocity Measurements ◽  
Vortex Control ◽  
Image Velocimetry ◽  
Wing Tip ◽  
Jet Blowing

AbstractAn experimental investigation was conducted to study the effect of synthetic jet (oscillatory, zero net mass flow jet) blowing near the wing tip, as a means of diffusing the trailing vortex. Velocity measurements were taken, using a Particle Image Velocimetry system, around the tip and in the near wake of a rectangular wing, which was equipped with several blowing slots. The effect of the synthetic jet was compared to that of a continuous jet blowing from the same configurations. The results show that the use of synthetic jet blowing is generally beneficial in diffusing the trailing vortex and comparable to the use of continuous jet. The effect was more pronounced for the highest blowing coefficient used. The driving frequency of the jet did not generally prove to be a significant parameter. Finally, the instantaneous and the phase-locked velocity measurements helped explain the different mechanisms employed by the continuous and synthetic jets in diffusing the trailing vortex.

Analytical Model: Characteristics of Nanosecond Pulsed Plasma Synthetic Jet Actuator in Multiple-Pulsed Mode

2017 ◽  
Vol 9 (2) ◽  
pp. 439-462 ◽  
Author(s):  
Zheng Li ◽  
Zhiwei Shi ◽  
Hai Du
Keyword(s):  
Flow Characteristics ◽  
Simulation Method ◽  
Synthetic Jet ◽  
Blast Waves ◽  
Pulsed Plasma ◽  
Synthetic Jet Actuator ◽  
Field Coupling ◽  
Neutral Gas ◽  
Pulsed Mode ◽  
Physical Principles

AbstractMulti-field coupling simulation method based on the physical principles is used to simulate the discharge characteristics of nanosecond pulsed plasma synthetic jet actuator. Considering the effect of the energy transferring for air, the flow characteristics of nanosecond pulsed plasma synthetic jet actuator are simulated. The elastic heating sources and ion joule heating sources are the two main sources of energy. Through the collisions, the energy of ions is transferred to the neutral gas quickly. The flow characteristics of a series of blast waves and the synthetic jet which erupt from the plasma synthetic jet (PSJ) actuator are simulated. The blast wave not only promotes outward, but also accelerates the gas mixing the inhaled gas from the outside cavity with the residual gas inside the cavity. The performances of PSJ actuator fluctuate in the first three incentive cycles and become stable after that.

Probing topological quantum phase transitions via photonic spin Hall effects in spin-orbit coupled 2D quantum materials

2021 ◽  
Author(s):  
Muzamil Shah
Keyword(s):  
Phase Transitions ◽  
Hall Effect ◽  
Extreme Values ◽  
Optical Transition ◽  
Quantum Phase Transitions ◽  
Measurement Techniques ◽  
Quantum Phase ◽  
Spin Hall Effect ◽  
Radiation Fields ◽  
Topological Quantum

Abstract Topological photonics is an emerging field in photonics in which various topological and geometrical ideas are used to manipulate and control the behavior of light photons. The interplay between topological matter and the spin degree of freedom of photons provides new opportunities for achieving spin-based photonics applications. In this paper, the photonic spin Hall effect (PSHE) of reflected light from the surface of the topological silicene quantum systems subjected to external electric and radiation fields in the terahertz regime is theoretically investigated. By tuning the external electric and the applied laser fields, we can drive the silicenic system through different topological quantum phase transitions. We demonstrate that the in-plane and transverse spatial spin dependent shifts exhibit extreme values near Brewster’s angles and away from the optical transition frequencies. We reveal that the photonic spin Hall shifts are sensitive to the spin and valley indices as well as to the number of closed gaps. By incorporating the quantum weak value measurement techniques, the photonic spin Hall effect greatly impact the research in spinoptics, spintronics, and valleytronics.

scholarly journals Novel Nozzle Shapes for Synthetic Jet Actuators Intended to Enhance Jet Momentum Flux

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 53 ◽  
Author(s):  
Jozef Kordík ◽  
Zdeněk Trávníček
Keyword(s):  
Momentum Flux ◽  
Element Model ◽  
Velocity Profiles ◽  
Input Power ◽  
Synthetic Jet ◽  
Stroke Length ◽  
Synthetic Jet Actuator ◽  
Pressure Loss Coefficient ◽  
Nozzle Plate ◽  
Lumped Element Model

An axisymmetric synthetic jet actuator based on a loudspeaker and five types of flanged nozzles were experimentally tested and compared. The first (reference) type of nozzle was a common sharp-edged circular hole. The second type had a rounded lip on the inside. The third nozzle type was assembled from these two types of nozzles—it had a rounded lip on the inside and straight section on the outside. The fourth nozzle was assembled using orifice plates such that the rounded lips were at both inner and outer nozzle ends. The last nozzle was equipped with an auxiliary nozzle plate placed at a small distance downstream of the main nozzle. The actuators with particular nozzles were tested by direct measurement of the synthetic jet (SJ) time-mean thrust using precision scales. Velocity profiles at the actuator nozzle exit were measured by a hot-wire anemometer. Experiments were performed at eight power levels and at the actuator resonance frequency. The highest momentum flux was achieved by the nozzle equipped with an auxiliary nozzle plate. Namely, an enhancement was approximately 31% in comparison with an effect of the reference nozzle at the same input power. Furthermore, based on the cavity pressure and the experimental velocity profiles, parameters for a lumped element model (mass of moving fluid and pressure loss coefficient) were evaluated. These values were studied as functions of the dimensionless stroke length.

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