Experimental characterization of high-speed impact damage behavior in a three-dimensionally woven SiC/SiC composite

2010 ◽  
Vol 41 (4) ◽  
pp. 489-498 ◽  
Author(s):  
Keiji Ogi ◽  
Tomonaga Okabe ◽  
Manabu Takahashi ◽  
Shigeki Yashiro ◽  
Akinori Yoshimura ◽  
...  
Keyword(s):  
High Speed ◽  
Impact Damage ◽  
Experimental Characterization ◽  
Damage Behavior ◽  
High Speed Impact

scholarly journals PS12 Characterization of high-speed impact damage in CFRP laminates

2012 ◽  
Vol 2012 (0) ◽  
pp. _PS12-1_-_PS12-3_
Author(s):  
Masamichi NAKATA ◽  
Takuya IOKA ◽  
keiji OGI
Keyword(s):  
High Speed ◽  
Impact Damage ◽  
Cfrp Laminates ◽  
High Speed Impact

4—CHARACTERIZATION OF THE HIGH-SPEED IMPACT BEHAVIOUR OF TEXTILE YARNS

1959 ◽  
Vol 50 (1) ◽  
pp. T55-T69 ◽  
Author(s):  
Jack C. Smith ◽  
Frank L. McCrackin ◽  
Herbert F. Schiefer
Keyword(s):  
High Speed ◽  
Impact Behaviour ◽  
High Speed Impact

Experimental Characterization of Intrinsic Properties Associated With Air-Assisted Liquid Jet and Liquid Sheet

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
K. Balaji ◽  
V. Sivadas ◽  
Vishnu Radhakrishna ◽  
Khushal Ashok Bhatija ◽  
K. Sai Charan
Keyword(s):  
High Speed ◽  
Liquid Sheet ◽  
Interfacial Instability ◽  
Wave Number ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Experimental Characterization ◽  
Interfacial Wave ◽  
Visualization Techniques

The present study focuses on experimental characterization of interfacial instability pertinent to liquid jet and liquid sheet in the first wind-induced zone. To accomplish this objective, the interfacial wave growth rate, critical wave number, and breakup frequency associated with air-assisted atomizer systems were extracted by utilizing high-speed flow visualization techniques. For a range of liquid to gas velocities tested, nondimensionalization with appropriate variables generates the corresponding correlation functions. These functions enable to make an effective comparison between interfacial wave developments for liquid jet and sheet configurations. It exhibits liquid sheets superiority over liquid jets in the breakup processes leading to efficient atomization.

Experimental Characterization of a Liquid Jet Emanating From An Effervescent Atomizer

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
V. Sivadas ◽  
K. Balaji ◽  
Antriksha Vishwakarma ◽  
Sundar Ram Manikandan
Keyword(s):  
High Speed ◽  
Flow Direction ◽  
Low Frequency ◽  
Intrinsic Property ◽  
Liquid Jet ◽  
Experimental Characterization ◽  
Jet Breakup ◽  
Effervescent Atomizer ◽  
Visualization Techniques

Abstract The study focuses on experimental characterization of the primary atomization associated with an effervescent atomizer. Unlike the existing designs available in the literature that inject air perpendicular to the liquid flow direction, the present atomizer design utilizes coflowing air configuration. In doing so, the aerodynamic shear at the liquid–gas interface create instability and enhance the subsequent jet breakup. Both integrated and intrinsic properties of the liquid jet were extracted by utilizing high-speed flow visualization techniques. The integrated property consists of breakup length, while the intrinsic property involves primary and intermediate breakup frequencies. The primary instability is characterized by low-frequency sinusoidal mode, whereas the intermediate instability consists of high-frequency dilatational mode. Dimensionless plots of these parameters with Weber number ratio leads to a better collapse of data, thereby generating appropriate universal functions. The combined diagram of frequencies converge with increasing relative velocity. This may be due to the dominance of energy consuming sinusoidal wave as the aerodynamic shear increases.

Experimental Characterization of Losses in Bladeless Turbine Prototype

2021 ◽  
Author(s):  
Avinash Renuke ◽  
Federico Reggio ◽  
Alberto Traverso ◽  
Matteo Pascenti
Keyword(s):  
High Speed ◽  
Electrical Power ◽  
Working Fluid ◽  
Small Scale ◽  
Experimental Characterization ◽  
Scaling Effects ◽  
Low Performance ◽  
Low Sensitivity ◽  
First Time

Abstract Multi-disk bladeless turbines, also known as Tesla turbines, are promising in the field of small-scale power generation and energy harvesting due to their low sensitivity to down-scaling effects, retaining high rotor efficiency. However, low (less than 40%) overall isentropic efficiency has been recorded in the experimental literature. This article aims for the first time to a systematic experimental characterization of loss mechanisms in a 3-kW Tesla expander using compressed air as working fluid and producing electrical power through a high speed generator (40krpm). The sources of losses discussed are: stator losses, stator-rotor peripheral viscous losses, end wall ventilation losses and leakage losses. After description of experimental prototype, methodology and assessment of measurement accuracy, the article discusses such losses aiming at separating the effects that each loss has on the overall performance. Once effects are separated, their individual impact on the overall efficiency curves is presented. This experimental investigation, for the first time, gives the insight into the actual reasons of low performance of Tesla turbines, highlighting critical areas of improvement, and paving the way to next generation Tesla turbines, competitive with state of the art bladed expanders.

Mechanical Characterization of Diamond-Like Carbon (DLC) Coated Polycarbonates

1993 ◽  
Vol 308 ◽  
Author(s):  
Alex J. Hsieh ◽  
Paul Huang ◽  
Shankar K. Venkataraman ◽  
David L. Kohlstedt
Keyword(s):  
High Speed ◽  
Mechanical Tests ◽  
Dominant Mode ◽  
Transverse Cracks ◽  
High Speed Impact ◽  
Dlc Coating ◽  
Bend Tests ◽  
Point Bend ◽  
The Impact

ABSTRACTEvaluations of DLC coated polycarbonates have been carried out via high speed projectile impact, three point bend, and continuous microscratch tests. Radial and circumferential microcracks appeared on the back surfaces and near the regions of impact as a result of the high speed impact stresses. Despite the impact, the adhesion of the DLC coating in the area between the cracks remained, except in the immediate vicinity of impact. In the three point bend tests, transverse cracks developed and propagated in the DLC coating when the applied strain reached the fracture limit of the coating. No delamination occurred in the continuous microscratch tests; instead, cracking of the coating was observed in DLC coated polycarbonates. Microcracking was the dominant mode of failure which was consistent in these three diversed mechanical tests. Results of the SEM studies further confirmed microcracking prior to delamination as observed in the high speed impact tested coupons.

scholarly journals Experimental characterization of speech aerosol dispersion dynamics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zu Puayen Tan ◽  
Lokesh Silwal ◽  
Surya P. Bhatt ◽  
Vrishank Raghav
Keyword(s):  
High Speed ◽  
Particle Image ◽  
Experimental Characterization ◽  
Production Rates ◽  
Plume Front ◽  
Fidelity Assessment ◽  
Image Velocimetry ◽  
Aerosol Dispersion ◽  
Primary Transmission

AbstractContact and inhalation of virions-carrying human aerosols represent the primary transmission pathway for airborne diseases including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Relative to sneezing and coughing, non-symptomatic aerosol-producing activities such as speaking are highly understudied. The dispersions of aerosols from vocalization by a human subject are hereby quantified using high-speed particle image velocimetry. Syllables of different aerosol production rates were tested and compared to coughing. Results indicate aerosol productions and penetrations are not correlated. E.g. ‘ti’ and ‘ma’ have similar production rates but only ‘ti’ penetrated as far as coughs. All cases exhibited a rapidly penetrating “jet phase” followed by a slow “puff phase.” Immediate dilution of aerosols was prevented by vortex ring flow structures that concentrated particles toward the plume-front. A high-fidelity assessment of risks to exposure must account for aerosol production rate, penetration, plume direction and the prevailing air current.

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