Terrence R. Meyer

Bio: Terrence R. Meyer is an academic researcher from Purdue University. The author has contributed to research in topics: Laser & Raman scattering. The author has an hindex of 39, co-authored 185 publications receiving 3661 citations. Previous affiliations of Terrence R. Meyer include Iowa State University & University of Erlangen-Nuremberg.

Femtosecond coherent anti-Stokes Raman scattering measurement of gas temperatures from frequency-spread dephasing of the Raman coherence

Abstract: Gas-phase temperatures and concentrations are measured from the magnitude and decay of the initial Raman coherence in femtosecond coherent anti-Stokes Raman scattering (CARS). A time-delayed probe beam is scattered from the Raman polarization induced by pump and Stokes beams to generate CARS signal; the dephasing rate of this initial coherence is determined by the temperature-sensitive frequency spread of the Raman transitions. Temperature is measured from the CARS signal decrease with increasing probe delay. Concentration is found from the ratio of the CARS and nonresonant background signals. Collision rates do not affect the determination of these quantities.

Emissions Characteristics of a Turbine Engine and Research Combustor Burning a Fischer−Tropsch Jet Fuel

Abstract: The emissions characteristics of two combustion platforms, a T63 turboshaft engine and an atmospheric swirl-stabilized research combustor, fueled with conventional military jet fuel (JP-8), a natural-gas-derived Fischer−Tropsch synthetic jet fuel (also referred herein as synjet or FT), and blends of the two were investigated. Nonvolatile particulate matter (PM) and gaseous emissions were analyzed to assess the impacts of the aromatic- and sulfur-free synjet fuel on the combustion products of the two platforms. The engine was operated at two power settings, and the combustor at several equivalence ratios, to evaluate the emission production over a wide range of combustion temperatures. Conventional aerosol instrumentation was used to quantify particle number (PN), size, and PM mass emissions, while a Fourier Transform Infrared analyzer was used to quantify the gaseous species. Planar laser-induced fluorescence and laser-induced incandescence techniques were employed on the research combustor to study the e...

Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering for high-speed gas-phase thermometry

Abstract: We demonstrate hybrid femtosecond/picosecond (fs/ps) coherent anti-Stokes Raman scattering for high-speed thermometry in unsteady high-temperature flames, including successful comparisons with a time- and frequency-resolved theoretical model. After excitation of the N(2) vibrational manifold with 100 fs broadband pump and Stokes beams, the Raman coherence is probed using a frequency-narrowed 2.5 ps probe beam that is time delayed to suppress the nonresonant background by 2 orders of magnitude. Experimental spectra were obtained at 500 Hz in steady and pulsed H(2)-air flames and exhibit a temperature precision of 2.2% and an accuracy of 3.3% up to 2400 K. Strategies for real-time gas-phase thermometry in high-temperature flames are also discussed, along with implications for kilohertz-rate measurements in practical combustion systems.

MHz-rate nitric oxide planar laser-induced fluorescence imaging in a Mach 10 hypersonic wind tunnel

Abstract: Nitric oxide planar laser-induced fluorescence (NO PLIF) imaging at repetition rates as high as 1MHz is demonstrated in the NASA Langley 31 in. Mach 10 hypersonic wind tunnel. Approximately 200 time-correlated image sequences of between 10 and 20 individual frames were obtained over eight days of wind tunnel testing spanning two entries in March and September of 2009. The image sequences presented were obtained from the boundary layer of a 20° flat plate model, in which transition was induced using a variety of different shaped protuberances, including a cylinder and a triangle. The high-speed image sequences captured a variety of laminar and transitional flow phenomena, ranging from mostly laminar flow, typically at a lower Reynolds number and/or in the near wall region of the model, to highly transitional flow in which the temporal evolution and progression of characteristic streak instabilities and/or corkscrew-shaped vortices could be clearly identified.

PIVlab – Towards User-friendly, Affordable and Accurate Digital Particle Image Velocimetry in MATLAB

Abstract: Digital particle image velocimetry (DPIV) is a non-intrusive analysis technique that is very popular for mapping flows quantitatively. To get accurate results, in particular in complex flow fields, a number of challenges have to be faced and solved: The quality of the flow measurements is affected by computational details such as image pre-conditioning, sub-pixel peak estimators, data validation procedures, interpolation algorithms and smoothing methods. The accuracy of several algorithms was determined and the best performing methods were implemented in a user-friendly open-source tool for performing DPIV flow analysis in Matlab.

Atomization and Sprays

Abstract: Preface 1.General Considerations 2.Basic Processes in Atomization 3.Drop Size Distributions of Sprays 4.Atomizers 5.Flow in Atomizers 6.Atomizer Performance 7.External Spray Charcteristics 8.Drop Evaporation 9.Drop Sizing Methods Index

Science and technology of ammonia combustion

Abstract: This paper focuses on the potential use of ammonia as a carbon-free fuel, and covers recent advances in the development of ammonia combustion technology and its underlying chemistry. Fulfilling the COP21 Paris Agreement requires the de-carbonization of energy generation, through utilization of carbon-neutral and overall carbon-free fuels produced from renewable sources. Hydrogen is one of such fuels, which is a potential energy carrier for reducing greenhouse-gas emissions. However, its shipment for long distances and storage for long times present challenges. Ammonia on the other hand, comprises 17.8% of hydrogen by mass and can be produced from renewable hydrogen and nitrogen separated from air. Furthermore, thermal properties of ammonia are similar to those of propane in terms of boiling temperature and condensation pressure, making it attractive as a hydrogen and energy carrier. Ammonia has been produced and utilized for the past 100 years as a fertilizer, chemical raw material, and refrigerant. Ammonia can be used as a fuel but there are several challenges in ammonia combustion, such as low flammability, high NOx emission, and low radiation intensity. Overcoming these challenges requires further research into ammonia flame dynamics and chemistry. This paper discusses recent successful applications of ammonia fuel, in gas turbines, co-fired with pulverize coal, and in industrial furnaces. These applications have been implemented under the Japanese ‘Cross-ministerial Strategic Innovation Promotion Program (SIP): Energy Carriers’. In addition, fundamental aspects of ammonia combustion are discussed including characteristics of laminar premixed flames, counterflow twin-flames, and turbulent premixed flames stabilized by a nozzle burner at high pressure. Furthermore, this paper discusses details of the chemistry of ammonia combustion related to NOx production, processes for reducing NOx, and validation of several ammonia oxidation kinetics models. Finally, LES results for a gas-turbine-like swirl-burner are presented, for the purpose of developing low-NOx single-fuelled ammonia gas turbine combustors.