The Impact of Manifold-to-Orifice Turning Angle on Sharp-Edge Orifice Flow Characteristics in Both Cavitation and Noncavitation Turbulent Flow Regimes

The approach taken was to analyze the results in a manner consistent with application by design engineers to new and existing applications, while providing some insight into the processes that are occurring. This paper deals with predicting the initiation of cavitation, cavitation impacts on the contraction coefficient (Cc), as well as noncavitation impacts on discharge coefficient (Cd) from L/D of five sharp-edge orifices over a turning angle range between 60 deg and 120 deg. The results show that in the cavitation regime, Cc is controlled by the cavitation parameter (Kcav), where the data follow the 1∕2 power with Kcav, and inception of cavitation occurs at a Kcav of 1.8. In the noncavitation regime for conditions where the cross velocity is 0 the data are consistent with the first order equation relating head loss (HL) to the dynamic pressure where KL is constant and is consistent with in-line orifices. Cross flow has a significant impact on loss coefficient and depends on both the turning angle and manifold inlet to orifice exit velocity ratio.

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Flow Characteristics of Contra- and Co-Rotating Swirler Arrangements of an Industrial Combustor

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2014-25860 ◽

2014 ◽

Cited By ~ 1

Author(s):

X. Wu ◽

E. R. Norster ◽

Gang Xie

Keyword(s):

Temperature Distribution ◽

Numerical Model ◽

Vortex Flow ◽

Flow Characteristics ◽

Cross Flow ◽

Outlet Temperature ◽

Gas Turbine Combustor ◽

Mean Velocity ◽

Split Ratio ◽

The Impact

This paper describes the investigation of the flow characteristics of two double radial inflow swirlers configured for use in a gas turbine combustor. The only difference between the two swirlers is in the contra- and co-rotating flow of air in the inner nozzle arrangement. The isothermal vortex flow field created by the double swirlers has been examined using numerical Model 1. The model also includes a cylinder reaction zone downstream of the swirler. The comparison of flow characteristics is carried out by examination of the spatial resolution of three mean velocity components. The contra- and co-rotating configurations show some discrepancy in terms of total loss factor and mass split ratio between the two swirlers. The comparison of flow fields also indicate that there is almost no remaining swirl further downstream in the contra-rotating configuration, while a significant amount of remaining swirl exists for the co-rotating option. The development of Model 1 to include a typical dilution zone and transition duct leads to numerical Model 2, which was used to investigate the impact on downstream mixing with the dilution air and the emerging temperature distribution at the transition duct exit. Comparing the temperature field for both configurations, the dilution effectiveness increases significantly with dilution jet penetration depth and reduces with spread along the circumferential direction. These effects lead to the central hot core persisting along the transition duct to the combustor outlet for the co-rotating option due to the combination of initial cross flow and a strong swirl, resulting in a considerable difference in the predicted outlet temperature distribution factors (OTDF) of 10.8% and 17.7% for the contra- and co-rotating arrangements, respectively.

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Study on the effect of alumina nano-fluid on sharp-edge orifice flow characteristics in both cavitations and non-cavitations turbulent flow regimes

Alexandria Engineering Journal ◽

10.1016/j.aej.2016.02.034 ◽

2016 ◽

Vol 55 (2) ◽

pp. 1099-1106 ◽

Cited By ~ 8

Author(s):

A.E. Kabeel ◽

Mohamed Abdelgaied

Keyword(s):

Turbulent Flow ◽

Flow Characteristics ◽

Flow Regimes ◽

Sharp Edge ◽

Nano Fluid ◽

Orifice Flow

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Numerical Study of Counter Jet Formed by Impinging Jets in Cross-Flow and its Effect on Mixing

Volume 4A: Combustion, Fuels and Emissions ◽

10.1115/gt2017-64197 ◽

2017 ◽

Cited By ~ 1

Author(s):

Thomas A. Epalle ◽

Fabien Gaugain ◽

Vincent Melot ◽

Nasser Darabiha ◽

Olivier Gicquel

Keyword(s):

Numerical Study ◽

Velocity Ratio ◽

Flow Characteristics ◽

Cross Flow ◽

Passive Scalar ◽

Impinging Jets ◽

Mean Velocity ◽

Plane Flow ◽

Flow Mixing ◽

Mixing Chambers

In this paper we will numerically analyse flow mixing in multiple jets in a crossflow. The system comprises a row of six radially-distributed injectors around the main pipe. The configuration represents mixing zones in industrial systems where a counter jet can be formed in the injection plane. Flow mixing can be modified as a result of geometry and injection velocities. We propose a simple model to describe the counter jet length as a function of injection flow characteristics. We also develop empirical laws to help engineers design practical test facilities. We then vary the velocity ratio to obtain both impinging and non-impinging jets in the injection plane. The focus is mainly on flow characteristics around the radial injection plane in the case of impinging jets, examining the mixing quality and efficiency by introducing a passive scalar discharge in a nitrogen flow. The mean velocity and width of the counter jet are finally analyzed by changing the injection velocities. These results are compared to those of non-impinging jets. It is found that the non-impinging jet configurations are convenient for short length mixing chambers, while the impinging ones should be considered in the case of longer mixing chambers.

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Changing landscapes: Gay men in the west and northwest of Ireland

Sexualities ◽

10.1177/1363460720981699 ◽

2020 ◽

pp. 136346072098169

Author(s):

Aidan McKearney

Keyword(s):

Gay Men ◽

Social Rights ◽

Irish Society ◽

Recent Past ◽

Same Sex ◽

Lgbt People ◽

The Many ◽

Northwest Region ◽

The Impact ◽

Insight Into

This article focuses on the experiences of gay men in the rural west and northwest region of Ireland, during a period of transformational social and political change in Irish society. These changes have helped facilitate new forms of LGBTQI visibility, and local radicalism in the region. Same-sex weddings, establishment of rural LGBT groups and marching under an LGBT banner at St Patricks Day parades would have been unthinkable in the recent past; but they are now becoming a reality. The men report continuing challenges in their lives as gay men in the nonmetropolitan space, but the emergence of new visibility, voice and cultural acceptance of LGBT people is helping change their lived experiences. The study demonstrates the impact of local activist LGBT citizens. Through their testimonies we can gain an insight into the many, varied and interwoven factors that have interplayed to create the conditions necessary for the men to: increasingly define themselves as gay to greater numbers of people in their localities; to embrace greater visibility and eschew strategies of silence; and aspire to a host of legal, political, cultural and social rights including same-sex marriage. Organic forms of visibility and local radicalism have emerged in the region and through an analysis of their testimonies we can see how the men continue to be transformed by an ever-changing landscape.

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Double, triple or quadruple hits? Exploring the impact of cybercrime on victims in the Netherlands

International Review of Victimology ◽

10.1177/02697580211010692 ◽

2021 ◽

pp. 026975802110106

Author(s):

Raoul Notté ◽

E.R. Leukfeldt ◽

Marijke Malsch

Keyword(s):

Public Opinion ◽

Literature Review ◽

The Netherlands ◽

Public Discourse ◽

Moral Judgments ◽

Victim Blaming ◽

High Prevalence ◽

Different Types ◽

The Impact ◽

Insight Into

This article explores the impact of online crime victimisation. A literature review and 41 interviews – 19 with victims and 22 with experts – were carried out to gain insight into this. The interviews show that most impacts of online offences correspond to the impacts of traditional offline offences. There are also differences with offline crime victimisation. Several forms of impact seem to be specific to victims of online crime: the substantial scale and visibility of victimhood, victimisation that does not stop in time, the interwovenness of online and offline, and victim blaming. Victims suffer from double, triple or even quadruple hits; it is the accumulation of different types of impact, enforced by the limitlessness in time and space, which makes online crime victimisation so extremely invasive. Furthermore, the characteristics of online crime victimisation greatly complicate the fight against and prevention of online crime. Finally, the high prevalence of cybercrime victimisation combined with the severe impact of these crimes seems contradictory with public opinion – and associated moral judgments – on victims. Further research into the dominant public discourse on victimisation and how this affects the functioning of the police and victim support would be valuable.

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Insight into the Impact of Zr/Ti Ratios on the Structure and Properties of PLZST Antiferroelectric Thick Films

physica status solidi (a) ◽

10.1002/pssa.202000579 ◽

2021 ◽

Author(s):

Yucheng Liu ◽

Shaopeng Liu ◽

Tongqing Yang

Keyword(s):

Thick Films ◽

Structure And Properties ◽

Antiferroelectric Thick Films ◽

The Impact ◽

Insight Into

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An improved de Laval nozzle experiment

International Journal of Mechanical Engineering Education ◽

10.1177/03064190211034165 ◽

2021 ◽

pp. 030641902110341

Author(s):

Nicholas Goodman ◽

Brian J Leege ◽

Peter E Johnson

Keyword(s):

Data Acquisition ◽

Laval Nozzle ◽

Flow Characteristics ◽

Data Acquisition System ◽

Isentropic Flow ◽

Hands On ◽

De Laval Nozzle ◽

Physical Phenomena ◽

The Impact ◽

The Relationship

Exposing students to hands-on experiments has been a common approach to illustrating complex physical phenomena that have been otherwise modelled solely mathematically. Compressible, isentropic flow in a duct is an example of such a phenomenon, and it is often demonstrated via a de Laval nozzle experiment. We have improved an existing converging/diverging nozzle experiment so that students can modify the location of the normal shock that develops in the diverging portion to better understand the relationship between the shock and the pressure. We have also improved the data acquisition system for this experiment and explained how visualisation of the standing shock is now possible. The results of the updated system demonstrate that the accuracy of the isentropic flow characteristics has not been lost. Through pre- and post-laboratory quizzes, we show the impact on student learning as well.

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Using syndromic measures of mortality to capture the dynamics of COVID-19 in Java, Indonesia, in the context of vaccination rollout

BMC Medicine ◽

10.1186/s12916-021-02016-2 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Bimandra A. Djaafara ◽

Charles Whittaker ◽

Oliver J. Watson ◽

Robert Verity ◽

Nicholas F. Brazeau ◽

...

Keyword(s):

Rural Areas ◽

Vaccination Campaign ◽

Control Measures ◽

Additional Insight ◽

Short Term ◽

If Current ◽

Vaccine Impact ◽

Potential Impact ◽

The Impact ◽

Insight Into

Abstract Background As in many countries, quantifying COVID-19 spread in Indonesia remains challenging due to testing limitations. In Java, non-pharmaceutical interventions (NPIs) were implemented throughout 2020. However, as a vaccination campaign launches, cases and deaths are rising across the island. Methods We used modelling to explore the extent to which data on burials in Jakarta using strict COVID-19 protocols (C19P) provide additional insight into the transmissibility of the disease, epidemic trajectory, and the impact of NPIs. We assess how implementation of NPIs in early 2021 will shape the epidemic during the period of likely vaccine rollout. Results C19P burial data in Jakarta suggest a death toll approximately 3.3 times higher than reported. Transmission estimates using these data suggest earlier, larger, and more sustained impact of NPIs. Measures to reduce sub-national spread, particularly during Ramadan, substantially mitigated spread to more vulnerable rural areas. Given current trajectory, daily cases and deaths are likely to increase in most regions as the vaccine is rolled out. Transmission may peak in early 2021 in Jakarta if current levels of control are maintained. However, relaxation of control measures is likely to lead to a subsequent resurgence in the absence of an effective vaccination campaign. Conclusions Syndromic measures of mortality provide a more complete picture of COVID-19 severity upon which to base decision-making. The high potential impact of the vaccine in Java is attributable to reductions in transmission to date and dependent on these being maintained. Increases in control in the relatively short-term will likely yield large, synergistic increases in vaccine impact.

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