Pdf planar laser induced fluorescence in aqueous flows. The experimental rig is a quarterwavelength acoustic resonator where a standing wave imposes oscillatory flow conditions. These diagnostics employ a tunable ir source to excite overtone and combination band transitions of co and co2, respectively, and one or two insb focal plane arrays to collect fluorescence emitted via fundamental transitions from excited vibrational states. Quantitative planar laserinduced fluorescence technology. A nonintrusive technique called was planar laser induced fluorescence plif was developed to measure the temperature field around a cavitation bubble. Planar laser induced fluorescence plif is a highly sensitive and spacetimeresolved laser diagnostic technique. Planar laserinduced fluorescence plif is a highly sensitive and spacetime resolved laser diagnostic technique. These techniques are employed to overcome some important problems identified in the literature and earlystage experimental trials with planar laserinduced fluorescence plif. Laserinduced fluorescence spectroscopy lif sciencedirect. Laser induced fluorescence lif is an established technique for spatially resolved imaging of gas temperature, pressure, velocity, and gaseous species along a laser beam 15 or in a laser sheet 611.
Planar laserinduced fluorescence plif measurements of nitric oxide no have been obtained in atmospheric pressure, laminar, partially premixed ethaneair flames. A fluorescent dye is used as a scalar proxy, and local fluorescence caused by excitation from a thin laser sheet can be related to dye concentration. Fluorescence power versus laser irradiance saturated regime 1. Infrared ir planar laserinduced fluorescence plif techniques for imaging of carbon monoxide and carbon dioxide are reported. The laser sheet, aligned vertically, is passed through the. Spatially and temporally resolved gas distributions around. Planar laser induced fluorescent plif systems provide measurements of scalar quantities. The opo is pumped by the thirdharmonic output of a multimode nd.
Laserinduced spontaneous emission multistep process. Using planar laserinduced fluorescence to study plasma. We report on highspeed ch planar laser induced fluorescence plif imaging in turbulent diffusion flames using a multimodepumped optical parametric oscillator opo. Exploring the dynamics of optical thermocavitation bubbles. Introduction to planar laserinduced fluorescence plif.
Application of planar laser induced fluorescence plif. The goal of this work was to contrast and compare the 2d and 3d flame topography of a turbulent flame. Planar laserinduced fluorescence plif is a highly sensitive and. Advanced integrated hardware and software system applying planar laser induced fluorescence plif as an optical diagnostic technique used for flow visualization and quantitative measurements. A laser light sheet is passed through the flowing gas or fluid. Acetone planar laserinduced fluorescence for supersonic flow visualization in air and nitrogen jet vikas m shelar1, shrisha rao mv1, gm hegde3, g umesh2, g jagadeesh1 and kpj reddy1 abstract background. Yag cluster for direct signal excitation in the ax 0,0 band of the ch radical. Nitric oxide planar laserinduced fluorescence no plif planar laserinduced fluorescence, or plif, is a nonintrusive flow diagnostic tool that can acquire planar snapshots of flow in wind tunnels, engines, and other flow systems. Plif can be used for temperature, concentration, pressure measurements and others. Laser induced fluorescence lif has become a common detector of atoms and molecules allowing to determine their internal state distributions. Plif systems kenelec scientific planar laser induced. Fibercoupled, 10 khz simultaneous oh planar laserinduced. In this paper we mention the advantages of both kinds.
Figure 1 below shows the heart of the plif technique from a macroscopic viewpoint. Flame imaging of highly turbulent premixed methaneair. Nitric oxide planar laserinduced fluorescence no plif. In plif, laser light, typically from a pulsed laser for high peak power, is shaped into a thin sheet and passed through the regions of interest to excite fluorescent tracers premixed in the fluid flow. Planar laser induced fluorescence plif measurements of nitric oxide no have been obtained in atmospheric pressure, laminar, partially premixed ethaneair flames. The overall experimental system consists of a 5 khz oh plif. Infrared planar laserinduced fluorescence with a cw quantum. Nowadays, the plif technology is developing in two directions. Original article open access acetone planar laserinduced. Planar laserinduced fluorescence plif and particleimage velocimetry piv techniques that employ freestanding optics face severe challenges when implemented in harsh environments associated with practical combustion facilities because of limited optical access and restrictions on operation of sensitive laser systems. The planar laserinduced fluorescence plif technique was implemented to measure mixing time in a 117 water model of a 200ton ladle furnace. Acetone planar laser induced fluorescence for supersonic flow visualization in air and nitrogen jet vikas m shelar1, shrisha rao mv1, gm hegde3, g umesh2, g jagadeesh1 and kpj reddy1 abstract background. Nonintrusive laser diagnostics, planar laser induced fluorescence plif and laser doppler velocimetry ldv, have been implemented to measure the dimensionless density difference and velocity in saltwater plumes. Lavision was founded in 1989 as a spinoff from max planck institute and laser laboratory in goettingen, germany.
Introduction 2 1 laser absorption pulsed or cw laser h. Based on the physics of interaction between light and molecules, lif allows for species selective measurements with high sensitivity, enabling measurements of minor combustion species to be made. Pdf introducing the planar laserinduced fluorescence. Planar laser induced fluorescence plif flow visualization. Laser induced fluorescence lif or laser stimulated fluorescence lsf is a spectroscopic method in which an atom or molecule is excited to a higher energy level by the absorption of laser light followed by spontaneous emission of light. To circumvent this problem, we have developed and implemented a fiber. Planar laser induced fluorescence plif lif imaging is a very sensitive laser imaging technique for species concentration, mixture fraction and temperature measurements in fluid mechanical processes, sprays and combustion systems. A nonintrusive laser based measurement system has been applied for the first time in the hymets hypersonic materials environmental test system 400 kw archeated wind tunnel at nasa langley research center. Planar laser induced fluorescence plif is used by the combustion branch. For this study, rhodamine wt fluorescent dye was mixed into the solution to be sprayed. The 2d measurements were obtained using chbased methylidyne radicalbased planar laser induced fluorescence plif, and the 3d measurements were obtained through a tomographic chemiluminescence tc technique.
The technique involves rapidly scanning a laser sheet across a flow field of interest. Further improvement of plif will not only advance the progress of lasce, but will also open doors to applications in the fields where controlled cavitation. To advance these applications, the effects of cw laser induced cavitation on its surroundings must be understood. The plif technique has been used to measure concentration gradients for combustion applications, but its use to quantify thermal gradients is limited. Both plif and tc were performed simultaneously on a turbulent. Planar laserinduced fluorescence plif is an optical diagnostic technique widely used in fluid and gas applications.
David davidson introduction the following is a brief history of the accomplishments of the hanson research group in developing and maturing the planar laserinduced fluorescence technique. Oh planar laser induced fluorescence plif measurements. It is widely used in the diagnosis of combustion and flow fields to obtain the thermodynamic information of active components and interested molecules in flames. Laser induced fluorescence lif department of aerospace. The lasing threshold, conversion efficiency, and linewidth are shown to depend on. Laser induced fluorescence lif fluorescent dyes molecules can absorb light at one frequency and subsequently reemit fluoresce light at a different frequency. Planar laser induced fluorescence in aqueous flows.
Refer to the section titled using other lasers with the lif detector for more information. A study of the normal injection of hydrogen into a heated. Planar laser induced fluorescence plif is used by the combustion branch at the nasa glenn research center nasa glenn to assess the characteristics of the flowfield produced by aircraft fuel injectors. Zachariah chemical science and technology laboratory, national institute of standards and technology, gaithersburg, maryland 20899. In experiments, the dyes are excited by laser light whose frequency closely matches the excitation frequency of the dye. Zachariah chemical science and technology laboratory, national institute of standards and technology. Plif was simultaneously first reported as a method to measure oh in 1982 by kychakoff and coworkers and dyer and crosley 9, 10. Nitric oxide planar laser induced fluorescence no plif the figure below shows an experimental image of the uppersurface flow structure on a fuselageonly x33 wind tunnel model at mach 10, obtained at nasa langley research center. The dominant uses of lif have changed over time, emphasizing different aspects of the special properties of laser light. Osa comparison of 2d and 3d flame topography measured by. Spatially and temporally resolved gas distributions around heterogeneous catalysts using infrared planar laserinduced fluorescence johan zetterberg, a, 1 sara blomberg, 2 johan gustafson, 2 jonas evertsson, 2 jianfeng zhou, 1 emma c. A study of quantitative concentrations of hydroxyl oh in. Twocolor, toluene based, planar laser induced fluorescence plif is utilized to characterize the thermal structure of a turbulent, free jet. Laser induced fluorescence planar lif for flow visualization.
In laser induced fluorescence lif the excitation photons are provided by a laser. Infrared planar laserinduced fluorescence with a cw. Emission lif signal this is the laser induced fluorescence possible collisional change. Planar laserinduced fluorescence plif investigation of.
However, at pressures above 10 atmospheres, attenuation of the excitation laser in the hot combustion gases. Timeresolved 3d oh planar laserinduced fluorescence. Pdf on jan 3, 2019, zhen yang and others published quantitative. To improve and expand the capabilities of the plif system new equipment was installed. Twodimensional laserinduced fluorescence imaging of. Plif is a technique in which a laser source is tuned to the absorption line of an atomic or molecular species present in a given plasma. Laser based flow visualization techniques are indispensable tools for flow visualization in fluid dynamics and combustion diagnostics.
Structured planar laserinduced fluorescence splif for the. Planar laser induced fluorescence of naturally occurring nitric oxide no has been used to obtain instantaneous flow visualization images. Plif has been shown to be used for velocity, concentration, temperature and pressure measurements. Laser induced fluorescence general introduction to lif. Both plif and tc were performed simultaneously on a turbulent premixed bunsen. Flame dynamics and flame growth and evolution of methaneair flames stabilized over a backward facing step at high reynolds number re re 15000 and re 30000 with an. The flow visualization technique planar laser induced fluorescence plif is commonly employed for characterization of scalar mixing. Laser induced spontaneous emission multistep process. Analysis of planar laserinduced fluorescence images. Laser induced fluorescence lif is the most powerful technique for experimental diagnostics of combustion processes available today.
These techniques are employed to overcome some important problems identified in the literature and earlystage experimental trials with planar laser induced fluorescence plif. Laserinduced fluorescence imaging in freepiston shock. The images were used to determine both h11 jet penetration depth profiles and twodimensional temperature maps of the combustion region. Pdf structured planar laserinduced fluorescence splif.
Planar laser induced fluorescence plif taking into. The objective was to quantify plif measurements in partially premixed flames across which there exists a significant range of quenching environments. Singlelaserpulse plif imaging of no, t, and velocity 1989. Planar laserinduced fluorescence plif is an optical diagnostic technique widely used for flow visualization and quantitative measurements. What is laserinduced fluorescence lif laserinduced spontaneous emission. Flame extinction simultaneous scalarflow measurements. Planar laserinduced fluorescence plif is a nonintrusive technique for measuring scalar concentrations in fluid flows. When lif is implemented in a 2d fashion it is often referred to planar laserinduced fluorescence plif, and is then highly spatially resolved along all three dimensions down to 50.
Laser induced fluorescence lifplif it is a powerful diagnostic tool for the investigation of nonreacting as well as reacting gas and liquid flows. The wavelength of the laser is tuned to a specific absorption line in a molecular species within the fluid, or to. Emission lif signal this is the laserinduced fluorescence possible collisional change. Laser induced fluorescence imaging in freepiston shock tunnels a thesis submitted for the degree of doctor of philosophy of the australian national university philip charles palma submitted may 1998 revised february 1999.
The 2d measurements were obtained using chbased methylidyne radicalbased planar laserinduced fluorescence plif, and the 3d measurements were obtained through a tomographic chemiluminescence tc technique. In plif, laser light, typically from a pulsed laser for high peak power, is. Fluorescence indicates that an excited atom or molecule is spontaneously emitting light, and the rest specifies that a laser sheet is generating these excited atomsmolecules. Levinton and trintchouk have chosen to evaluate the potential use of planar laserinduced fluorescence to investigate plasmaedge turbulence. However, to date the vast majority of lif and planarlif plif work has been conducted at ultraviolet uv and visible vis wavelengths. The term lif has existed since shortly after the birth of the laser itself sternlicht et al. Oh planar laser induced fluorescence plif ntrs nasa. Laser induced fluorescence lif techniques using excitation in the ax and dx electronic systems have proven a reliable technique for twodimensional imaging of nitric oxide concentrations in practical combustion systems. Using laser induced fluorescence application note piv012 plif measurements of mixing appear across a range of disciplines including combustion diagnostics, fundamental turbulence and fluid mechanics, microfluidics, environmental engineering, contaminant hydrogeology, and industrial mixing processes for a range of. The department of mechanical and industrial engineering. Pdf quantitative planar laserinduced fluorescence technology. Quantification of planar laserinduced fluorescence. Introduction to planar laserinduced fluorescence plif stanford. The overall experimental system consists of a 5 khz oh plif system, a high.
Fluorescence efficiency th fl i li l ti l t th i t l i di 21 21 tot p 12 l a q the fluorescence is linearly proportional to the input laser irradiance since most often a 21 laser induced fluorescence plif is a nonintrusive technique for measuring scalar concentrations in fluid flows. Oh planar laser induced fluorescence plif measurements for. The article presents an investigation of ch cx planar laser induced fluorescence imaging plif of highly turbulent methaneair flames inside a windowed combustor. Measurement of hydroxyl oh concentration of transient. Lif imaging is a molecule specific visualization method with high spatial and temporal resolution. Planar laser induced fluorescence plif is an optical diagnostic technique widely used in fluid and gas applications. Adams, 3 peranders carlsson, 3 marcus alden, 1 and edvin lundgren 2. Planar laserinduced fluorescence plif imaging has, in recent years, been shown to be a powerful nonintrusive diagnostic technique for the study of aerodynamic flow phenomena. Timeresolved 3d oh planar laserinduced fluorescence system. Pdf planar laserinduced fluorescence plif is a nonintrusive technique for measuring scalar concentrations in fluid flows.
Plif has proven to be a valuable tool for flow visualization as well as for quantitative wholefield measurements of concentration and temperature in liquid and concentration in gaseous flows. Laserinduced fluorescence lif is an established technique for spatially resolved imaging of gas temperature, pressure, velocity, and gaseous species along a laser beam 15 or in a laser sheet 611. Laser induced fluorescence plif was developed to measure the temperature field around a cavitation bubble. A 488 nm argonion laser is available from beckman coulter. Laserinduced fluorescence lif fluorescent dyes molecules can absorb light at one frequency and subsequently reemit fluoresce light at a different frequency. The hydroxyl radical oh was used as the plif target species in the flow because it is an important and prominent intermediary. Highspeed ch planar laserinduced fluorescence imaging using. In this paper, we use planar laserinduced fluorescence of nitric oxide to visualize four different hypersonic flowfields. Realtime gasphase imaging over a pd110 catalyst during co. Planar laser induced fluorescence plif is an optical diagnostic technique widely used for flow visualization and quantitative measurements. Planar laserinduced fluorescence plif is a highly sensitive and spacetimeresolved laser diagnostic technique. Plif accomplishments of the hanson group principal investigator. Photek application note planar laser induced fluorescence planar laser induced fluorescence plif is a common analytical technique used to study gas and fluid flows.
Imaging of co and co2 using infrared planar laserinduced. Planar laserinduced fluorescence plif was used to image the flow. A study of quantitative concentrations of hydroxyl oh in laminar flat flames using planar laser induced fluorescence plif a thesis presented. Nitric oxide plif measurements in the hypersonic materials.