Download or read book Jet Impingement Onto a Circular Cylinder written by Seyed Pariviz Alavi Tabrizi and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Experimental Study of Jet Impingement on a Circular Cylinder written by Dennis Wayne Potts and published by . This book was released on 1984 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: A round turbulent jet was impinged normally upon a circular cylinder and the resulting flow field was studied. The investigation was conducted using a jet which issued from a nozzle with an 11/16 inch diameter. The cylinder had a diameter of 6 5/8 inches. The jet impinged upon the cylinder at nozzle distances of 7, 15, and 30 nozzle diameters, and at velocities of 400 and 500 ft/s. The free jet was studied and found to be 'typical' by comparing it to earlier studies done with round turbulent jets. Surface flow visualization tests were performed to determine the direction of the flow. The wall jet about the cylinder, resulting from the impinging jet, was studied. Measurements of the velocity profiles and turbulence intensities were made. These results were compared to the same information obtained for flat plates and found to be similar for the nozzle distance of 7 diameters. At nozzle distances of 15 and 30 diameters the data was no longer similar. From velocity measurements, the spread rates and decay rates of the wall jet were determined. These results were compared to similar studies done for flat plates. Decay rates were found to be less than that of flat plates and spread rates were greater than that of flat plates, especially about the circumference of the cylinder.

Download or read book Synthetic Jet Impingement Heat Transfer from a Circular Cylinder written by Krishan Gopal and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decade has seen a dramatic rise in the research on synthetic jet (SJ) impingement cooling and heat transfer. This is primarily due to the many advantages of a SJ that include its low cost, simple structure, light weight, ease of installation and ability to be miniaturised using MEMs technology, making it a very promising alternative to other technologies in use. Consequently, a large body of literature exists on the impingement of SJ normally on a heated flat surface. The demand for cooling technologies however is not limited to target objects having flat surfaces only. Real applications can present a whole range of geometrical situations, with curved surfaces, and tight spaces with bounding walls. In spite of this, there exists very little research and information beyond the SJ impinging on flat surfaces in unconfined environments. An obvious deviation from a flat surface is a surface with curvature. For the specific situation of a circular cylinder, very few studies, if any, have been carried out in the past for analysing the heat transfer characteristics of SJ impingement. This research work was therefore aimed at investigating the flow and heat transfer characteristics of a slot synthetic jet (SJ) impinging on a circular cylinder. Specifically, it focussed on the influence of the geometric arrangements and flow conditions on the flow dynamics of the slot SJ, flow characteristics associated with the SJ impingement on a circular cylinder and the resulting thermal behaviour of the SJ. A bench-top synthetic jet actuator driven by a magnetic shaker via a loudspeaker diaphragm was utilised for the study. The SJ was generated from a slot of dimensions w = 6.4 mm x h = 160 mm (aspect ratio h/w of 25), with a jet Reynolds number of 2,400-3,900 (based on the slot width). To help understand the characteristics of the impingement fluid dynamics and heat transfer, a detailed investigation of the SJ flow field (in the absence of the cylinder) was first carried out. In this regard, an important aspect of the research was aimed at generating detailed understanding of the SJ flow-field characteristics in a bounded region. In a number of generic situations, this work is of high importance as the SJ could potentially be deployed for cooling applications in constrained environments. To attain a constrained environment, two parallel sidewalls were mounted along the shorter side of the slot extending in the streamwise direction to constrain the flow along the slot span. Hot-wire anemometry was used to explore the flowfield characteristics of the SJ ensuing in both a free (i.e. without sidewalls) and the constrained environment. To establish the flow and thermal characteristics of the SJ impingement, two instrumented aluminium cylinders of diameter, D of 19 mm, having a curvature ratio D/w of 3 were fabricated. The first was equipped for unsteady surface pressure measurements, while the second with a uniform surface temperature for heat transfer analysis. The cylinders were traversed along the jet centreline over non-dimensional distances from the slot of H/w = 5-50, corresponding to the SJ jet near-field through the developing region to the fully developed region. In addition, smoke flow visualizations were conducted to gain insights into the flow dynamics associated with the SJ flow-field with and without sidewalls, and SJ impinging on the cylinder. The experimental investigation for the SJ with and without sidewalls revealed that the presence of the sidewalls strongly influences the SJ flow-field. For instance, jet spreading rate reduced by almost 31.5 % with a corresponding rise in the statistically two-dimensional region in the slot downstream with the inclusion of the sidewalls. In addition, the phenomenon of axisswitching was found to be absent in the SJ flow-field in the presence of the sidewalls. Other jet properties such as the turbulence intensity, skewness, and flatness factors further revealed the differences in the flow-field of the two configurations. Furthermore, the experimental results for the SJ impinging on a circular cylinder showed that the flow-field behaviour differs significantly from that of a cylinder in uniform flow and is largely affected by the jet-cylinder separation distance and the operating environment i.e., free or constrained. For instance, the plots of the pressure distribution and normalized standard deviation of the fluctuating pressure around the cylinder surface revealed higher flow fluctuations associated with SJ impingement. The flow visualization and the hot wire measurements further unveiled that there was no obvious vortex shedding that occurs in the cylinder wake; instead evidence for vortex dipoles rising from the cylinder surface was found, on either side of the cylinder. Under uniform cylinder surface temperature conditions, the thermal performance of SJ impingement was found to be governed by the Reynolds number, jet cylinder separation distance and the excitation frequency, as might be expected from the literature on SJ impingement on flat surfaces. The SJ was found to perform better in the constrained environment, attributed to relatively higher flow fluctuations developed by the complex interaction of the vortex with the sidewall boundary layer and the cylinder. Almost 12% higher average heat transfer was observed in the case of the constrained environment over the range of parameters employed in the current work. Moreover, a strong dependence of heat transfer on the jet cylinder separation distance was also found. In contrast to the SJ impinging on flat target surfaces where the maximum heat transfer was attained in the intermediate field, at H/w = 14 to 18, for SJ impingement on the circular cylinder however, this was consistently attained in the near field i.e., H/w = 5. Also, the thermal performance as a function of the flow Reynolds number was found comparable to the uniform flow case, when the Reynolds number was based on the approach flow velocity (i.e. local velocity based on the cylinder location) instead of the velocity at the slot exit. The present study revealed for the first time, the flow and heat transfer behaviour of the SJ impinging on a circular cylinder in free and constrained environments. The results of the study may serve as a guide for SJ based solutions for various heating or cooling applications.

Download or read book Normal Impingement of a Circular Liquid Jet Onto a Screen in a Weightless Environment written by Eugene P. Symons and published by . This book was released on 1976 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow and Heat transfer Characteristics for a Two dimensional Jet Impinging on a Circular Cylinder written by Hiromichi Miyazaki and published by . This book was released on 1975 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer from a Circular Cylinder Due to a Slot Jet Impingement written by Adnan Abdul-Rahman Alhomoud and published by . This book was released on 1984 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pressure and Temperature Sensitive Paints written by Tianshu Liu and published by Springer Science & Business Media. This book was released on 2006-01-06 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Luminescent molecule sensors, called pressure-sensitive paint (PSP) and temperature-sensitive paint (TSP), measure factors essential for understanding the aerodynamic performance and heat transfer characteristics of flight vehicles. They provide a powerful tool for experimental aerodynamicists to obtain a deeper understanding of the rich physical phenomena in complex flows around a flight vehicle. This book helps the reader to understand the physics and chemistry and the capabilities of PSP and TSP. It provides an overview of the wide scope of applications and explains the system requirements for using these sensors. The book also includes an extensive table of properties of PTP and TSP. As such, it is a thorough and up-to-date coverage of the underlying physics and applications of luminescent molecules designed for global pressure and temperature mapping

Download or read book Risk Reliability and Safety Innovating Theory and Practice written by Lesley Walls and published by CRC Press. This book was released on 2016-11-25 with total page 4767 pages. Available in PDF, EPUB and Kindle. Book excerpt: The safe and reliable performance of many systems with which we interact daily has been achieved through the analysis and management of risk. From complex infrastructures to consumer durables, from engineering systems and technologies used in transportation, health, energy, chemical, oil, gas, aerospace, maritime, defence and other sectors, the management of risk during design, manufacture, operation and decommissioning is vital. Methods and models to support risk-informed decision-making are well established but are continually challenged by technology innovations, increasing interdependencies, and changes in societal expectations. Risk, Reliability and Safety contains papers describing innovations in theory and practice contributed to the scientific programme of the European Safety and Reliability conference (ESREL 2016), held at the University of Strathclyde in Glasgow, Scotland (25—29 September 2016). Authors include scientists, academics, practitioners, regulators and other key individuals with expertise and experience relevant to specific areas. Papers include domain specific applications as well as general modelling methods. Papers cover evaluation of contemporary solutions, exploration of future challenges, and exposition of concepts, methods and processes. Topics include human factors, occupational health and safety, dynamic and systems reliability modelling, maintenance optimisation, uncertainty analysis, resilience assessment, risk and crisis management.

Download or read book NASA Technical Paper written by and published by . This book was released on 1984 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow Control Techniques and Applications written by Jinjun Wang and published by Cambridge University Press. This book was released on 2019 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master the theory, applications and control mechanisms of flow control techniques.

Download or read book Synthetic Jets written by Kamran Mohseni and published by CRC Press. This book was released on 2014-09-17 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiles Information from a Multitude of SourcesSynthetic jets have been used in numerous applications, and are part of an emergent field. Accumulating information from hundreds of journal articles and conference papers, Synthetic Jets: Fundamentals and Applications brings together in one book the fundamentals and applications of fluidic actuators.

Download or read book Advances in Heat Transfer Augmentation Techniques in Single Phase Flows written by Varun Goel and published by CRC Press. This book was released on 2024-01-26 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Augmentation of heat transfer is important in energy conservation and developing sustainable energy systems. This book provides the science necessary to understand the basics of heat transfer augmentation in single-phase engineering systems. It considers theory and practice including computational and experimental procedures, evaluation techniques for performance, and new trends. Several applications of augmentation methods like surface modification, introduction of vortex flow and impinging jets, opportunities of ultrasound and magnetic fields, pulsatile flows, heat exchangers, and nanofluids are provided. Details of basic phenomena and mechanisms are highlighted. Key features: Provides the fundamental science needed to understand and further develop heat transfer augmentation for future energy systems Give examples of how ultrasound and magnetic fields, vortex flow, impinging jets, surface modification and nanofluids can augment heat transfer Considers basic issues of computational and experimental methods for analysis, design, and evaluation of efficient and sustainable heat transfer It is an ideal reference text for graduate students and academic researchers working in the fields of mechanical, aerospace, industrial, manufacturing, and chemical engineering.

Download or read book Jet Interaction Test Program ccn No 39 written by A. I. Karydas and published by . This book was released on 1964 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and theoretical investigation was conducted to study the jet impingement forces on a right circular cylinder in the flow field of a rocket nozzle exhausting into a vacuum or near-vacuum environment. In the theoretical investigation, an approximate method based on radial flow of the exhaust jet and a Newtonian approximation was developed to predict the jet impingement forces on a cylinder in a vacuum. The experimental investigation was performed in the Aeronutronic high-altitude chamber to determine the jet impingement forces and pressures on two instrumented cylinder models. Unheated nitrogen gas was exhausted from a conical nozzle into the test chamber at a nominal starting altitude of 250,000 feet. Six positions of the cylindrical models relative to the nozzle exit were investigated. In general, results of the experimental investigation indicate that the forces measured under essentially vacuum conditions are applicable to the case of a pure vacuum environment. Good agreement was obtained between the experimental force results and the theoretical results. The experiments also indicate that the decrease in altitude during testing because of the addition of mass from the nozzle can have a significant effect on the jet impingement force. (Author).

Download or read book Food Engineering Integrated Approaches written by Gustavo F. Gutiérrez-Lopez and published by Springer Science & Business Media. This book was released on 2008-02-29 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a significant and up-to-date review of various integrated approaches to food engineering. Distinguished food engineers and food scientists from key institutions worldwide have contributed chapters that provide a deep analysis of their particular subjects. Emerging technologies and biotechnology are introduced, and the book discusses predictive microbiology, packing materials for foods, and biodegradable films. This book is mainly directed to academics, and to undergraduate and postgraduate students in food engineering and food science and technology, who will find a selection of topics.

Download or read book Impingement Jet Cooling in Gas Turbines written by R.S. Amano and published by WIT Press. This book was released on 2014-05-28 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the requirement for enhanced cooling technologies on modern gas turbine engines, advanced research and development has had to take place in field of thermal engineering. Among the gas turbine cooling technologies, impingement jet cooling is one of the most effective in terms of cooling effectiveness, manufacturability and cost. The chapters contained in this book describe research on state-of-the-art and advanced cooling technologies that have been developed, or that are being researched, with a variety of approaches from theoretical, experimental, and CFD studies. The authors of the chapters have been selected from some of the most active researchers and scientists on the subject. This is the first to book published on the topics of gas turbines and heat transfer to focus on impingement cooling alone.

Download or read book Fluid Structure Sound Interactions and Control written by Yu Zhou and published by Springer. This book was released on 2015-12-17 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings primarily focus on advances in the theory, experiments, and numerical simulations of turbulence in the contexts of flow-induced vibration and noise, as well as their control. Fluid-related structural vibration and noise problems are often encountered in many engineering fields, increasingly making them a cause for concern. The FSSIC conference, held on 5-9 July 2015 in Perth, featured prominent keynote speakers such as John Kim, Nigel Peake, Song Fu and Colin Hansen, as well as talks on a broad range of topics: turbulence, fluid-structure interaction, fluid-related noise and the control/management aspects of these research areas, many of which are clearly interdisciplinary in nature. It provided a forum for academics, scientists and engineers working in all branches of Fluid-Structure-Sound Interactions and Control (FSSIC) to exchange and share the latest developments, ideas and advances, bringing them together researchers from East and West to push forward the frontiers of FSSIC, ensuring that the proceedings will be of interest to a broad engineering community.