23,911 research outputs found

    Holographic flow visualization

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    Holographic visualization techniques are presented of the vortex wake of a lifting wing. The motions of tracer particles in vortical flows are described along with the development of a liquid-drop tracer generator. An analysis is presented of the motion of particles of arbitrary density and size in solid body and potential vortex flows

    New techniques for experimental generation of two-dimensional blade-vortex interaction at low Reynolds numbers

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    An experimental investigation of two dimensional blade vortex interaction was held at NASA Langley Research Center. The first phase was a flow visualization study to document the approach process of a two dimensional vortex as it encountered a loaded blade model. To accomplish the flow visualization study, a method for generating two dimensional vortex filaments was required. The numerical study used to define a new vortex generation process and the use of this process in the flow visualization study were documented. Additionally, photographic techniques and data analysis methods used in the flow visualization study are examined

    Uncertain Flow Visualization using LIC

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    In this paper we look at the Line Integral Convolution method for flow visualization and ways in which this can be applied to the visualization of two dimensional, steady flow fields in the presence of uncertainty. To achieve this, we start by studying the method and reviewing the history of modifications other authors have made to it in order to improve its efficiency or capabilities, and using these as a base for the visualization of uncertain flow fields. Finally, we apply our methodology to a case study from the field of oceanography

    Off-surface infrared flow visualization

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    A method for visualizing off-surface flows is provided. The method consists of releasing a gas with infrared absorbing and emitting characteristics into a fluid flow and imaging the flow with an infrared imaging system. This method allows for visualization of off-surface fluid flow in-flight. The novelty of this method is found in providing an apparatus for flow visualization which is contained within the aircraft so as not to disrupt the airflow around the aircraft, is effective at various speeds and altitudes, and is longer-lasting than previous methods of flow visualization

    Development of a flow visualization apparatus

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    The use of an optical flow visualization device for studying convection flow patterns was investigated. The investigation considered use of a shadowgraph, schlieren and other means for visualizing the flow. A laboratory model was set up to provide data on the proper optics and photography procedures to best visualize the flow. A preliminary design of a flow visualization system is provided as a result of the study. Recommendations are given for a flight test program utilizing the flow visualization apparatus

    Operational flow visualization techniques in the Langley Unitary Plan Wind Tunnel

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    The unitary plan wind tunnel (UPWT) uses in daily operation are shown. New ideas for improving the quality of established flow visualization methods are developed and programs on promising new flow visualization techniques are pursued. The unitary plan wind tunnel is a supersonic facility, referred to as a production facility, although the majority of tests are inhouse basic research investigations. The facility has two 4 ft. by 4 ft. test sections which span a Mach range from 1.5 to 4.6. The cost of operation is about $10 per minute. Problems are the time required for a flow visualization test setup and investigation costs and the ability to obtain consistently repeatable results. Examples of sublimation, vapor screen, oil flow, minitufts, schlieren, and shadowgraphs taken in UPWT are presented. All tests in UPWT employ one or more of the flow visualization techniques

    Flow visualization

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    Tato bakalářská práce pojednává o metodách vizualizace proudění tekutin a to ve vzduchu i ve vodě. Nejprve je uvedena stručná charakteristika základních pojmů souvisejících s prouděním tekutiny, jako je například proudnice, laminární a turbulentní proudění. Dále jsou uvedeny používané vizualizační metody, rozdělené podle určitých typů a použití pro kapalinu nebo plyn. Tyto metody poskytují kvalitativní pohled na proudění a umožňují vytvořit si přehled o vlastnostech proudění plynů nebo kapalin. Některé z těchto metod jsou jednoduché a některé jsou složitější. Na závěr je uveden popis realizovaného jednoduchého experimentu vizualizace proudění v kapalině za pomocí velmi výkonného laserového ukazovátka.This bachelor´s thesis deals with fluid flow visualization methods in the air and water. First brief characteristic of the basic concepts of fluid flow is described, such as streamline, laminar and turbulent flow. The described visualization methods are divided into certain types and are used for fluid or gas. These methods provide a qualitative view of the flow and create the overview of the characteristics of gas or liquid flow. Some of these methods are simple and some are more complex. Finally, a simple experiment of liquids flow visualization is described by very powerful laser pointer.
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