Experimental Characterization of a Novel Piezoelectric Fan

2019 ◽  
Author(s):  
Jingru Benner ◽  
Eric Shilyuk ◽  
Jarrod Coletta ◽  
Mehdi Mortazavi ◽  
Anthony D. Santamaria ◽  
...  
Keyword(s):  
Numerical Model ◽  
Flow Rate ◽  
High Speed ◽  
Leading Edge ◽  
Low Noise ◽  
Camera System ◽  
Low Energy Consumption ◽  
2D Numerical Model ◽  
Piezoelectric Fans

Abstract Piezoelectric fans have attracted attentions in the past decades because of their low energy consumption, low noise level, light weight and reliability. A novel form of piezoelectric flapping fan is characterized experimentally and numerically. An experimental setup was built to measure the pressure and flow rate of piezoelectric fans with low static pressure at various frequencies. The fan performance curve was established. A high speed camera system was used to analyze the oscillation motion of the fan wings. The displacement of the leading edge and trailing edge of the piezoelectric fan wings are used as inputs to describe the deflection of the fan in the numerical model. The flow field obtained from the model is analyzed. The vortex shedding is observed and discussed. The pressure and flow rate obtained from the 2D numerical model are compared with the experimental results. The results provide a fundamental understanding of a piezoelectric fan with opposing oscillating wings.

Dynamic Damage of Aircraft Wing Leading Edge Impacted by Birds

2013 ◽  
Vol 385-386 ◽  
pp. 292-295 ◽  
Author(s):  
Liu Jun
Keyword(s):  
High Speed ◽  
Leading Edge ◽  
Test Results ◽  
Aircraft Wing ◽  
Camera System ◽  
Edge Structure ◽  
Whole Process ◽  
Laser Velocity ◽  
Certification Requirements ◽  
Structure Configuration

In order to verify the preliminary design of Aircraft Wing Leading Edge structures to bird impacting loads. The tests of bird impacting on Wing Leading Edge structure configurations were carried out using the relevant experimental facility. The impacting velocity was measured by laser velocity finder. The structure configuration was impacted by bird on three points and the whole process of dynamic deformation and damage on bird and Wing Leading Edge structure were recorded using high speed camera system. The test results showed that the leading edge slat was weak in anti-bird impacting and can not satisfy the airworthiness certification requirements. At the meantime the test results provid abundant experimental validation datas for the numerical simulation model applied in birds impacting.

High Speed Characterization of Pseudomorphic Hemt Structures Using a Very Low Noise Scintillation Detector

1993 ◽  
Vol 37 ◽  
pp. 145-151
Author(s):  
N. Loxley ◽  
S. Cockerton ◽  
B. K. Tanner
Keyword(s):  
Quality Assurance ◽  
Scintillation Detector ◽  
High Speed ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Low Noise ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Dynamic

AbstractWe show that a very low noise, high dynamic range scintillation detector has major advantages over conventional detectors for characterization of pseudomorphic HEMT structures by high resolution X-ray diffraction. We show that the reduced background enables a second modulation period to be detected, enabling the thickness and composition to be determined independently. Using a conventional X-ray generator and diffractometer we demonstrate that, in a single scan taking only 10 seconds, we are able to obtain sufficiently good data to provide quality assurance.

Effect of Leading Edge Sweep on Cavitation Performance of Two-Bladed Flat Plate Inducer

2011 ◽  
Author(s):  
Takaki Igoshi ◽  
Yuki Uchinono ◽  
Emosi Koroitamana ◽  
Koichi Ishizaka ◽  
Satoshi Watanabe ◽  
...  
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Internal Flow ◽  
Leading Edge ◽  
Pressure Measurements ◽  
Flow Measurements ◽  
Cavitation Performance ◽  
Video Observations ◽  
Flow Rate Range ◽  
Suction Performance

The installation of inducer upstream of main impeller is an effective method to improve the suction performance of turbopump. However, various types of cavitation instabilities are known to occur even at the designed flow rate as well as in the partial flow rate range. In the present study, we focus on the leading edge sweep of inducer and investigate its effect on the suction performance as well as on the onset of cavitation surge phenomenon. Flow measurements including casing wall pressure measurements, high-speed video observations, and limiting streamline observations are carried out, and discussions will be made based on those results about the influence of backward leading edge sweep on the internal flow of the inducer as well as its relation to the cavitation performance.

scholarly journals Test stand for pulsed jet actuator command and characterization

2021 ◽  
Vol 2130 (1) ◽  
pp. 012031
Author(s):  
W Stryczniewicz ◽  
W Stalewski
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Sensor ◽  
Leading Edge ◽  
Test Stand ◽  
Design Stage ◽  
Testing Procedures ◽  
Pulsed Jet

Abstract The paper presents a test stand for characterization of a new design of a Pulsed Jet Actuator. The aim of the work was to characterize the performance of the PJA in terms of air parameters in the air supply line and velocity at the PJA outlet. To perform a detailed characterization of the system performance, the test bench comprised: a pressure reductor, a mass flow rate controller, a mass flow rate meter, a pressure sensor, a fast pressure sensor, a flow temperature sensor and a Constant Temperature Anemometer. The PJA was commanded by a real time controller with Field Programmed Gate Array architecture. The experimental results show good agreement with the results of Computational Fluid Dynamics simulations performed at the design stage of the PJA. It has been found that the flow parameters at the PJA nozzle outlet match the design goals. The developed bench testing procedures will be used for silent conditions tests of the PJA system integrated into a leading edge of a wind tunnel model.

Effects of Alternate Leading Edge Cutback on Unsteady Cavitation in 4-Bladed Inducers

2001 ◽  
Vol 123 (4) ◽  
pp. 762-770 ◽  
Author(s):  
Yoshiki Yoshida ◽  
Yoshinobu Tsujimoto ◽  
Dai Kataoka ◽  
Hironori Horiguchi ◽  
Fabien Wahl
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Leading Edge ◽  
Cavitation Number ◽  
The Other ◽  
Low Flow ◽  
Pressure Measurements ◽  
High Speed Video ◽  
Cavitation Performance ◽  
Wide Range

A set of 4-bladed inducers with various amounts of cutback was tested with the aim of suppressing the rotating cavitation by applying alternate leading edge cutback. Unsteady cavitation patterns were observed by means of inlet pressure measurements and high-speed video pictures. It was found that the region with the alternate blade cavitation and asymmetric cavitation were enlarged with the increase of the amount of the cutback. As a result, the region with the rotating cavitation was diminished. At low flow rate, two types of alternate blade cavitation were found as predicted theoretically on 4-bladed inducer with smaller uneven blade length. One of them is with longer cavities on longer blades, and the other is with longer cavities on shorter blades. Switch was observed in these alternate blade cavitation patterns depending whether the cavitation number was increased or decreased. For an inducer with larger amount of cutback, the rotating cavitation and cavitation surge were almost suppressed as expected for a wide range of flow rate and cavitation number, although the cavitation performance was deteriorated. However, we should note that an asymmetric cavitation pattern occurs more easily in inducers with alternate leading edge cutback, and that the unevenness due to the cutback causes uneven blade stress.

Numerical Model Updating Technique for Estimating Load Carrying Capacities of High Speed Railway Bridges

2016 ◽  
Vol 106 (8) ◽  
pp. 490-497
Author(s):  
Dong-Uk PARK ◽  
Jae-Bong KIM ◽  
Nam-Sik KIM ◽  
Sung-Il KIM
Keyword(s):  
Numerical Model ◽  
High Speed ◽  
Model Updating ◽  
High Speed Railway ◽  
Railway Bridges ◽  
Load Carrying
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