Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Mach number. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Ultrahigh-frame-rate OH fluorescence imaging in turbulent flames using a burst-mode optical parametric oscillator.

Abstract: Burst-mode planar laser-induced fluorescence (PLIF) imaging of the OH radical is demonstrated in laminar and turbulent hydrogen-air diffusion flames with pulse repetition rates up to 50 kHz. Nearly 1 mJ/pulse at 313.526 nm is used to probe the OH P(2)(10) rotational transition in the (0,0) band of the A-X system. The UV radiation is generated by a high-speed-tunable, injection-seeded optical parametric oscillator pumped by a frequency-doubled megahertz-rate burst-mode Nd:YAG laser. Preliminary kilohertz-rate wavelength scanning of the temperature-broadened OH transition during PLIF imaging is also presented for the first time (to our knowledge), and possible strategies for spatiotemporally resolved planar OH spectroscopy are discussed.

Using material behavior models to develop process control strategies

Abstract: Advances in material behavior modeling have enabled the explicit incorporation of material phenomena into process design and control methodologies. A new approach to material behavior modeling, in which stability analysis has been combined with the analysis of activation energy, can be used to identify processing regimes within which the material behavior is essentially deterministic and is amenable to process control. This articles illustrates the application of this dynamic material modeling approach through the example of deformation processing of a δ-TiAl alloy. Additionally, a new control-system design strategy explicitly based on the knowledge of the state of the material under hot-deformation conditions is explored.

Loss of coherency of the alpha/beta interface boundary in titanium alloys during deformation

Abstract: The loss of coherency of interphase boundaries in two-phase titanium alloys during deformation was analyzed The energy of the undeformed interphase boundary was first determined by means of the van der Merwe model for stepped interfaces The subsequent loss of coherency was ascribed to the increase of interphase energy due to absorption of lattice dislocations and was quantified by a relation similar to the Read–Shockley equation for low-angle boundaries in single-phase alloys It was found that interphase boundaries lose their coherency by a strain of approximately 05 at T = 800°C