Frank Beyrau

Bio: Frank Beyrau is an academic researcher from Otto-von-Guericke University Magdeburg. The author has contributed to research in topics: Particle image velocimetry & Particle. The author has an hindex of 30, co-authored 118 publications receiving 2171 citations. Previous affiliations of Frank Beyrau include Imperial College London & University of Erlangen-Nuremberg.

High-speed planar thermometry and velocimetry using thermographic phosphor particles

Abstract: Simultaneous gas-phase temperature and velocity imaging using micrometer-size thermographic phosphor particles seeded into the flow is demonstrated at a 3 kHz repetition rate. The velocity field is measured using a standard particle image velocimetry approach, while the temperature is determined from the temperature sensitive phosphorescence emission of the particles following excitation at 355 nm. Since the particles are very small, they rapidly assume the temperature and velocity of the surrounding gas. A single shot temperature precision of better than 5 % was achieved at 500 K. Time-resolved measurements in the wake of a heated cylinder are presented, demonstrating the utility of these imaging diagnostics to observe transient, coupled heat and mass transfer phenomena.

Simultaneous temperature, mixture fraction and velocity imaging in turbulent flows using thermographic phosphor tracer particles

Abstract: This paper presents an optical diagnostic technique based on seeded thermographic phosphor particles, which allows the simultaneous two-dimensional measurement of gas temperature, velocity and mixture fraction in turbulent flows. The particle Mie scattering signal is recorded to determine the velocity using a conventional PIV approach and the phosphorescence emission is detected to determine the tracer temperature using a two-color method. Theoretical models presented in this work show that the temperature of small tracer particles matches the gas temperature. In addition, by seeding phosphorescent particles to one stream and non-luminescent particles to the other stream, the mixture fraction can also be determined using the phosphorescence emission intensity after conditioning for temperature. The experimental technique is described in detail and a suitable phosphor is identified based on spectroscopic investigations. The joint diagnostics are demonstrated by simultaneously measuring temperature, velocity and mixture fraction in a turbulent jet heated up to 700 K. Correlated single shots are presented with a precision of 2 to 5% and an accuracy of 2%.

Flame front detection and characterization using conditioned particle image velocimetry (CPIV).

Abstract: We investigate the ability of the conditioned particle image velocimetry technique (CPIV) to derive the actual flame front position in turbulent premixed flames. In CPIV, the flame front shape is deduced from the step in the particle number density in PIV images caused by the steep temperature increase in the reaction zone of premixed flames. In a validation experiment the true flame front position is deduced for comparison from simultaneous heat release measurements using planar LIF measurements of OH and CH(2)O. It is found that CPIV yields nearly the same spatial position as the heat release measurements or the steepest slope in the OH distribution. Furthermore, statistical quantities, derived from the extracted flame front shape, like the spatially resolved turbulent flux, the flame surface density and the flame front curvature are compared, showing negligible differences between the applied methods.

Gas-phase temperature measurement in the vaporizing spray of a gasoline direct-injection injector by use of pure rotational coherent anti-Stokes Raman scattering.

Abstract: Pure rotational coherent anti-Stokes Raman spectroscopy is applied for quantitative gas-phase temperature measurements in the vaporizing spray of an automotive fuel injector. Interferences from elastically scattered stray light are greatly reduced by use of a polarization technique and spectral filtering in a double monochromator. The applicability of this technique to probing low-temperature sprays is successfully demonstrated.

Applied Combustion Diagnostics

Abstract: The editors have assembled a world-class group of contributors who address the questions the combustion diagnostic community faces. They are chemists who identify the species to be measured and the interfering substances that may be present; physicists, who push the limits of laser spectroscopy and laser devices and who conceive suitable measuremen