Author: Franck Kolczak
Publisher:
ISBN:
Category :
Languages : en
Pages : 488
Book Description
Temperature Measurements in a Flow Using Laser Induced Fluorescence of Oxygen
Author: Franck Kolczak
Publisher:
ISBN:
Category :
Languages : en
Pages : 488
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 488
Book Description
Temperature Measurements in Gases Using Planar Laser-induced Fluorescence Imaging of NO and O2
Author: Michael Poliang Lee
Publisher:
ISBN:
Category : Aerodynamic measurements
Languages : en
Pages : 182
Book Description
Three techniques based on Planar Laser-Induced Fluorescence (PLIF) have been developed for the measurement of 2-D temperature fields in gaseous flows. The methods are applicable to a wide range of aerodynamic and combustion flows.
Publisher:
ISBN:
Category : Aerodynamic measurements
Languages : en
Pages : 182
Book Description
Three techniques based on Planar Laser-Induced Fluorescence (PLIF) have been developed for the measurement of 2-D temperature fields in gaseous flows. The methods are applicable to a wide range of aerodynamic and combustion flows.
Optical Measurements of Fluctuating Temperatures in a Supersonic Turbulent Flow Using One- and Two-photon, Laser-induced Fluorescence
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
A Quantitative Study of the Feasibility of Oxygen Laser Induced Fluorescence for Engineering Gas Temperature Measurements
Author: Ismail Ceyhan
Publisher:
ISBN:
Category :
Languages : en
Pages : 194
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 194
Book Description
Two-Dimensional Imaging Measurements in Supersonic Flows Using Laser-Induced Fluorescence of Oxygen
Author: L. M. Cohen
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Planar laser induced fluorescence of molecular oxygen in a supersonic jet of heated air is reported. A tunable, narrow-bandwidth ArF excimer laser was used to excite a rovibronic transition of oxygen in the Schumann-Runge band system at 193 nm. A comparison between the predicted pressure and temperature profiles obtained in the underexpanded round jet with the fluorescence image data is presented. Keywords: Laser, Fluorescence, Imaging, Oxygen, Supersonic Flow, Excimer.
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Planar laser induced fluorescence of molecular oxygen in a supersonic jet of heated air is reported. A tunable, narrow-bandwidth ArF excimer laser was used to excite a rovibronic transition of oxygen in the Schumann-Runge band system at 193 nm. A comparison between the predicted pressure and temperature profiles obtained in the underexpanded round jet with the fluorescence image data is presented. Keywords: Laser, Fluorescence, Imaging, Oxygen, Supersonic Flow, Excimer.
Handbook Of Flow Visualization
Author: Wen Jei Yang
Publisher: Routledge
ISBN: 1351442619
Category : Technology & Engineering
Languages : en
Pages : 723
Book Description
With contributions from some of the world's leading experts, the second edition of this classic reference compiles all major techniques of flow visualization and demonstrates their applications in all fields of science and technology. A new chapter has been added that covers flow visualization applications in large wide tunnels for airplane and automobile testing. Several important examples of applications are included. A second new chapter details the use of infrared (IR) cameras for detecting and observing the boundary layer transition in industrial wind tunnels and flight testing of commercial transport airplanes. A final new chapter has been added on multiphase flow and pulsed-light velocimetry.
Publisher: Routledge
ISBN: 1351442619
Category : Technology & Engineering
Languages : en
Pages : 723
Book Description
With contributions from some of the world's leading experts, the second edition of this classic reference compiles all major techniques of flow visualization and demonstrates their applications in all fields of science and technology. A new chapter has been added that covers flow visualization applications in large wide tunnels for airplane and automobile testing. Several important examples of applications are included. A second new chapter details the use of infrared (IR) cameras for detecting and observing the boundary layer transition in industrial wind tunnels and flight testing of commercial transport airplanes. A final new chapter has been added on multiphase flow and pulsed-light velocimetry.
Experimental Determination of Oxygen and Nitrogen Recombination Coefficients at Elevated Temperature Using Laser-induced Fluorescence
Author: Jochen Marschall
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 18
Book Description
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 18
Book Description
Single-pulse Gas Thermometry at Low Temperatures Using Two-photon Laser-induced Fluorescence in NO/N2 Mixtures
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 20
Book Description
Tracer-based Planar Laser-induced Fluorescence Diagnostics
Author: Brian Ho-yin Cheung
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 197
Book Description
Two advances to tracer-based planar laser-induced fluorescence (PLIF) diagnostics are presented in this work. The first improvement is the development of a 3-pentanone fluorescence quantum yield (FQY) database and model for a wide range of conditions in support of quantitative PLIF diagnostics. In addition, this work presents a sensitive, time-resolved tracer-based PLIF diagnostic, accomplished by using a continuous-wave (CW) laser with the high-FQY tracer toluene. Because of its ease of use and desirable photophysical properties, PLIF diagnostics using 3-pentanone as a tracer are common, particularly for internal combustion engine (ICE) diagnostics. Thus, there is a need for 3-pentanone FQY measurements and modeling over a wide range of temperatures, pressures, and excitation wavelengths. For insight into the collisionless process in the FQY model, measurements were made in 3-pentanone vapor at low-pressures across a range of temperatures using a flowing cell. Laser excitation with 248, 266, 277, 308 nm wavelengths were utilized, and Rayleigh scattering of the laser beam was used to calibrate the optical efficiency of the collection optics and detector. This low-pressure data allows calculation of the 3-pentanone fluorescence rate and non-radiative de-excitation rate in the fluorescence model. The vibrational relaxation cascade parameter for 3-pentanone collisions was also determined. Measurements of 3-pentanone FQY were also made over a range of temperatures and pressures relevant to diagnostic applications, and, in particular, combined high-temperature and high-pressure conditions applicable to internal combustion engines (ICE). These data were collected in a custom-built optical cell capable of simultaneous high-pressure and high-temperature conditions. The behavior of the FQY in nitrogen for temperatures up to 745 K and in air up to 570 K was examined for pressures from 1 to 25 bar. These data were used to further optimize the parameters in the FQY model representing collisional processes. The large quantity of data with 308 nm excitation allowed optimization of the nitrogen quenching rate, and data in air were used to optimize the oxygen quenching rate. These data were also used to optimize the vibrational relaxation parameters for nitrogen and oxygen. The model with the updated parameters is consistent with the data collected in the current work, as well as with fluorescence measurements made in optical ICEs up to 1100 K and 28 bar. Another area of tracer-based PLIF diagnostics development is time-resolved imaging. Because PLIF diagnostics are often performed using pulsed lasers, the time resolution of measurements is limited to the pulse rate of laser. Use of a high-powered visible laser with an off-the-shelf cavity frequency doubler is shown to produce a moderate-power CW beam in the ultraviolet wavelength regime. Application of this CW source to excite toluene, a high-FQY tracer, yields a sensitive, time-resolved tracer-based PLIF diagnostic. Fluctuation detection limits for tracer mole fraction were investigated by applying the diagnostic to an atmospheric temperature and pressure nitrogen jet seeded with 4% toluene, and detection limits of better than 1% of the maximum toluene mole fraction were achieved for detection of fluorescence signal at a point, along a line, and over a plane. The diagnostic was also demonstrated on a turbulent jet for line and planar detection and demonstrated the potential for toluene time-resolved PLIF diagnostics with CW lasers.
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 197
Book Description
Two advances to tracer-based planar laser-induced fluorescence (PLIF) diagnostics are presented in this work. The first improvement is the development of a 3-pentanone fluorescence quantum yield (FQY) database and model for a wide range of conditions in support of quantitative PLIF diagnostics. In addition, this work presents a sensitive, time-resolved tracer-based PLIF diagnostic, accomplished by using a continuous-wave (CW) laser with the high-FQY tracer toluene. Because of its ease of use and desirable photophysical properties, PLIF diagnostics using 3-pentanone as a tracer are common, particularly for internal combustion engine (ICE) diagnostics. Thus, there is a need for 3-pentanone FQY measurements and modeling over a wide range of temperatures, pressures, and excitation wavelengths. For insight into the collisionless process in the FQY model, measurements were made in 3-pentanone vapor at low-pressures across a range of temperatures using a flowing cell. Laser excitation with 248, 266, 277, 308 nm wavelengths were utilized, and Rayleigh scattering of the laser beam was used to calibrate the optical efficiency of the collection optics and detector. This low-pressure data allows calculation of the 3-pentanone fluorescence rate and non-radiative de-excitation rate in the fluorescence model. The vibrational relaxation cascade parameter for 3-pentanone collisions was also determined. Measurements of 3-pentanone FQY were also made over a range of temperatures and pressures relevant to diagnostic applications, and, in particular, combined high-temperature and high-pressure conditions applicable to internal combustion engines (ICE). These data were collected in a custom-built optical cell capable of simultaneous high-pressure and high-temperature conditions. The behavior of the FQY in nitrogen for temperatures up to 745 K and in air up to 570 K was examined for pressures from 1 to 25 bar. These data were used to further optimize the parameters in the FQY model representing collisional processes. The large quantity of data with 308 nm excitation allowed optimization of the nitrogen quenching rate, and data in air were used to optimize the oxygen quenching rate. These data were also used to optimize the vibrational relaxation parameters for nitrogen and oxygen. The model with the updated parameters is consistent with the data collected in the current work, as well as with fluorescence measurements made in optical ICEs up to 1100 K and 28 bar. Another area of tracer-based PLIF diagnostics development is time-resolved imaging. Because PLIF diagnostics are often performed using pulsed lasers, the time resolution of measurements is limited to the pulse rate of laser. Use of a high-powered visible laser with an off-the-shelf cavity frequency doubler is shown to produce a moderate-power CW beam in the ultraviolet wavelength regime. Application of this CW source to excite toluene, a high-FQY tracer, yields a sensitive, time-resolved tracer-based PLIF diagnostic. Fluctuation detection limits for tracer mole fraction were investigated by applying the diagnostic to an atmospheric temperature and pressure nitrogen jet seeded with 4% toluene, and detection limits of better than 1% of the maximum toluene mole fraction were achieved for detection of fluorescence signal at a point, along a line, and over a plane. The diagnostic was also demonstrated on a turbulent jet for line and planar detection and demonstrated the potential for toluene time-resolved PLIF diagnostics with CW lasers.
Measurements of Density, Temperature, and Their Fluctuations in Turbulent Supersonic Flow Using UV Laser Spectroscopy
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Nonintrusive measurements of density, temperature, and their turbulent fluctuation levels have been obtained in the boundary layer of an unseeded, Mach 2 wind tunnel flow. The spectroscopic techniques that was used to make the measurements is based on the combination of laser-induced oxygen fluorescence and Raman scattering by oxygen and nitrogen from the same laser pulse. Results from this demonstration experiment are compared with previous measurements obtained in the same facility using conventional probes and an earlier spectroscopic technique. Densities and temperatures measured with the current technique agree with the previous surveys to within 3% and 2%, respectively. The fluctuation amplitudes for both variable agree with the measurements obtained using the earlier spectroscopic technique and show evidence of an unsteady, weak shock wave that perturbs the boundary layer. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 14
Book Description
Nonintrusive measurements of density, temperature, and their turbulent fluctuation levels have been obtained in the boundary layer of an unseeded, Mach 2 wind tunnel flow. The spectroscopic techniques that was used to make the measurements is based on the combination of laser-induced oxygen fluorescence and Raman scattering by oxygen and nitrogen from the same laser pulse. Results from this demonstration experiment are compared with previous measurements obtained in the same facility using conventional probes and an earlier spectroscopic technique. Densities and temperatures measured with the current technique agree with the previous surveys to within 3% and 2%, respectively. The fluctuation amplitudes for both variable agree with the measurements obtained using the earlier spectroscopic technique and show evidence of an unsteady, weak shock wave that perturbs the boundary layer. (Author).