Planar laser induced fluorescence plif measurements of nitric oxide no have been obtained in atmospheric pressure, laminar, partially premixed ethaneair flames. Both plif and tc were performed simultaneously on a turbulent. The objective was to quantify plif measurements in partially premixed flames across which there exists a significant range of quenching environments. 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. Singlelaserpulse plif imaging of no, t, and velocity 1989. These techniques are employed to overcome some important problems identified in the literature and earlystage experimental trials with planar laserinduced fluorescence plif. 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. Planar laser induced fluorescence plif is the 2d version of the. The department of mechanical and industrial engineering. Laserinduced fluorescence spectroscopy lif sciencedirect. 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. To advance these applications, the effects of cw laser induced cavitation on its surroundings must be understood. Fluorescence power versus laser irradiance saturated regime 1. 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.
Planar laserinduced fluorescence plif is an optical diagnostic technique widely used for flow visualization and quantitative measurements. The lasing threshold, conversion efficiency, and linewidth are shown to depend on. 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. Structured planar laserinduced fluorescence splif for. Laser induced fluorescence lif department of aerospace. The opo is pumped by the thirdharmonic output of a multimode nd. The planar laserinduced fluorescence plif technique was implemented to measure mixing time in a 117 water model of a 200ton ladle furnace. Validation of the laser system was accomplished using oh planar laserinduced fluorescence plif in a laminar hydrogenair flame produced by a hencken.
Laser induced fluorescence general introduction to lif. Levinton and trintchouk have chosen to evaluate the potential use of planar laserinduced fluorescence to investigate plasmaedge turbulence. Infrared planar laserinduced fluorescence with a cw quantum. Nowadays, the plif technology is developing in two directions. The images were used to determine both h11 jet penetration depth profiles and twodimensional temperature maps of the combustion region. 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. In laser induced fluorescence lif the excitation photons are provided by a laser. Thermal characterization of a turbulent free jet with. Flame extinction simultaneous scalarflow measurements. The overall experimental system consists of a 5 khz oh plif system, a high. We report on highspeed ch planar laser induced fluorescence plif imaging in turbulent diffusion flames using a multimodepumped optical parametric oscillator opo. Introduction to planar laserinduced fluorescence plif stanford.
Planar laserinduced fluorescence plif investigation of. 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. 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. 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. Planar laser induced fluorescence plif flow visualization. Twocolor, toluene based, planar laser induced fluorescence plif is utilized to characterize the thermal structure of a turbulent, free jet. Refer to the section titled using other lasers with the lif detector for more information. Imaging of co and co2 using infrared planar laserinduced. The dominant uses of lif have changed over time, emphasizing different aspects of the special properties of laser light. Laser induced fluorescence planar lif for flow visualization. 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. In this paper, we use planar laserinduced fluorescence of nitric oxide to visualize four different hypersonic flowfields.
A laser light sheet is passed through the flowing gas or fluid. Pdf structured planar laserinduced fluorescence splif. Laser induced fluorescence lif has become a common detector of atoms and molecules allowing to determine their internal state distributions. Planar laserinduced fluorescence plif was used to image the flow. Plif has been shown to be used for velocity, concentration, temperature and pressure measurements. Laser induced spontaneous emission multistep process. 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.
To improve and expand the capabilities of the plif system new equipment was installed. Planar laser induced fluorescence plif is an optical diagnostic technique widely used in fluid and gas applications. For this study, rhodamine wt fluorescent dye was mixed into the solution to be sprayed. 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. 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 laserinduced fluorescence plif is a highly sensitive and. The article presents an investigation of ch cx planar laser induced fluorescence imaging plif of highly turbulent methaneair flames inside a windowed combustor. The cameras are operated in the gate mode see the pimax or pimax3 manual. Laser induced fluorescence lif is the most powerful technique for experimental diagnostics of combustion processes available today. 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. 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.
The laser sheet, aligned vertically, is passed through the. 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. The technique involves rapidly scanning a laser sheet across a flow field of interest. Pdf planar laser induced fluorescence in aqueous flows. Advanced integrated hardware and software system applying planar laser induced fluorescence plif as an optical diagnostic technique used for flow visualization and quantitative measurements. In this paper we mention the advantages of both kinds. However, at pressures above 10 atmospheres, attenuation of the excitation laser in the hot combustion gases. We offer planar laser induced fluorescence plif system as an optical diagnostic technique used for flow visualization and quantitative measurements. Laserinduced fluorescence lif fluorescent dyes molecules can absorb light at one frequency and subsequently reemit fluoresce light at a different frequency. The overall experimental system consists of a 5 khz oh plif.
Lif imaging is a molecule specific visualization method with high spatial and temporal resolution. 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. Introduction 2 1 laser absorption pulsed or cw laser h. Nitric oxide planar laserinduced fluorescence no plif. Pdf on jan 3, 2019, zhen yang and others published quantitative. 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. Structured planar laserinduced fluorescence splif for the. Nitric oxide plif measurements in the hypersonic materials. Osa comparison of 2d and 3d flame topography measured by. Infrared planar laserinduced fluorescence with a cw. Plif was simultaneously first reported as a method to measure oh in 1982 by kychakoff and coworkers and dyer and crosley 9, 10. Oh planar laser induced fluorescence plif ntrs nasa. Laser based flow visualization techniques are indispensable tools for flow visualization in fluid dynamics and combustion diagnostics.
A nonintrusive technique called was planar laser induced fluorescence plif was developed to measure the temperature field around a cavitation bubble. Lavision was founded in 1989 as a spinoff from max planck institute and laser laboratory in goettingen, germany. Laserinduced fluorescence imaging in freepiston shock. Planar laserinduced fluorescence plif measurements of nitric oxide no have been obtained in atmospheric pressure, laminar, partially premixed ethaneair flames. Infrared ir planar laserinduced fluorescence plif techniques for imaging of carbon monoxide and carbon dioxide are reported. 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. A study of quantitative concentrations of hydroxyl oh in. Plif accomplishments of the hanson group principal investigator.
Analysis of planar laserinduced fluorescence images. Introduction to planar laserinduced fluorescence plif. Yag cluster for direct signal excitation in the ax 0,0 band of the ch radical. Photek application note planar laser induced fluorescence planar laser induced fluorescence plif is a common analytical technique used to study gas and fluid flows. Quantitative planar laserinduced fluorescence technology. 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. These techniques are employed to overcome some important problems identified in the literature and earlystage experimental trials with planar laser induced fluorescence plif. Realtime gasphase imaging over a pd110 catalyst during co. Laser induced fluorescence lif fluorescent dyes molecules can absorb light at one frequency and subsequently reemit fluoresce light at a different frequency. Oh planar laser induced fluorescence plif measurements for. The flow visualization technique planar laser induced fluorescence plif is commonly employed for characterization of scalar mixing.
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. Emission lif signal this is the laserinduced fluorescence possible collisional change. Adams, 3 peranders carlsson, 3 marcus alden, 1 and edvin lundgren 2. 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. Timeresolved 3d oh planar laserinduced fluorescence system. Pdf introducing the planar laserinduced fluorescence. Measurement of hydroxyl oh concentration of transient. Plif planar laser induced fluorescence plif is the 2d version of the lif technique. Twodimensional laserinduced fluorescence imaging of. To circumvent this problem, we have developed and implemented a fiber. Timeresolved 3d oh planar laserinduced fluorescence. 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. Highspeed ch planar laserinduced fluorescence imaging using.
Planar laser induced fluorescent plif systems provide measurements of scalar quantities. 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. In plif, the flow is illuminated by a laser light sheet whose wavelength is tuned to excite a particular. 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. Planar laser induced fluorescence plif is an optical diagnostic technique widely used for flow visualization and quantitative measurements. 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. Pdf planar laserinduced fluorescence plif is a nonintrusive technique for measuring scalar concentrations in fluid flows. A 488 nm argonion laser is available from beckman coulter. Original article open access acetone planar laserinduced. Plif can be used for temperature, concentration, pressure measurements and others. Planar laser induced fluorescence plif is a highly sensitive and spacetimeresolved laser diagnostic technique. Zachariah chemical science and technology laboratory, national institute of standards and technology. Oh planar laser induced fluorescence plif measurements.
Laserinduced spontaneous emission multistep process. Emission lif signal this is the laser induced fluorescence possible collisional change. The no plif method has been successfully applied in a variety of supersonic and hypersonic flow facilities. A study of quantitative concentrations of hydroxyl oh in laminar flat flames using planar laser induced fluorescence plif a thesis presented. Zachariah chemical science and technology laboratory, national institute of standards and technology, gaithersburg, maryland 20899. Pdf quantitative planar laserinduced fluorescence technology. The term lif has existed since shortly after the birth of the laser itself sternlicht et al. The laser induced fluorescence lif detector is available as an optional accessory. Both plif and tc were performed simultaneously on a turbulent premixed bunsen. However, to date the vast majority of lif and planarlif plif work has been conducted at ultraviolet uv and visible vis wavelengths. Planar laser induced fluorescence in aqueous flows. Planar laserinduced fluorescence plif is an optical diagnostic technique widely used in fluid and gas applications. 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. The experimental rig is a quarterwavelength acoustic resonator where a standing wave imposes oscillatory flow conditions.
The wavelength of the laser is tuned to a specific absorption line in a molecular species within the fluid, or to. Exploring the dynamics of optical thermocavitation bubbles. 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. Laser induced fluorescence lifplif it is a powerful diagnostic tool for the investigation of nonreacting as well as reacting gas and liquid flows. The hydroxyl radical oh was used as the plif target species in the flow because it is an important and prominent intermediary.
Planar laserinduced fluorescence plif is a highly sensitive and spacetime resolved laser diagnostic technique. The plif technique has been used to measure concentration gradients for combustion applications, but its use to quantify thermal gradients is limited. Flame imaging of highly turbulent premixed methaneair. Quantification of planar laserinduced fluorescence. Planar laser induced fluorescence plif is used by the combustion branch. Planar laserinduced fluorescence plif is a nonintrusive technique for measuring scalar concentrations in fluid flows. In experiments, the dyes are excited by laser light whose frequency closely matches the excitation frequency of the dye. 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. Fibercoupled, 10 khz simultaneous oh planar laserinduced.
In plif, laser light, typically from a pulsed laser for high peak power, is. Plif systems kenelec scientific planar laser induced. The goal of this work was to contrast and compare the 2d and 3d flame topography of a turbulent flame. 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.
Application of planar laser induced fluorescence plif. Laser induced fluorescence plif was developed to measure the temperature field around a cavitation bubble. Using planar laserinduced fluorescence to study plasma. 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. Spatially and temporally resolved gas distributions around. Planar laserinduced fluorescence plif is a highly sensitive and spacetimeresolved laser diagnostic technique. What is laserinduced fluorescence lif laserinduced spontaneous emission. A study of the normal injection of hydrogen into a heated.
563 492 1026 188 1297 1109 416 658 1180 686 820 208 850 1242 962 397 1375 42 160 1272 215 1113 26 230 959 803 1067 827 1135 1239 1404 211 281 1533 825 557 1287 1548 126 676 1309 1363 736 495 474 1153 135