Blowout and liftoff limits of a hydrogen jet flame in a supersonic, heated, coflowing air stream

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76310/1/AIAA-1993-446-753.pd

Simultaneous CH planar laser-induced fluorescence and particle imaging velocimetry in turbulent flames

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77055/1/AIAA-1998-151-822.pd

The study of the turbulent burning velocity by imaging the wrinkled flame surface

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76129/1/AIAA-2002-482-348.pd

Parallel fuel injection from the base of an extended strut into supersonic flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76778/1/AIAA-1994-711-873.pd

Measured supersonic flame properties - Heat-release patterns, pressure losses, thermal choking limits

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76611/1/AIAA-24093-582.pd

Spatially resolved mass flux measurements with dual comb spectroscopy

Providing an accurate, representative sample of mass flux across large open areas for atmospheric studies or the extreme conditions of a hypersonic engine is challenging for traditional intrusive or point-based sensors. Here, we demonstrate that laser absorption spectroscopy with frequency combs can simultaneously measure all of the components of mass flux (velocity, temperature, pressure, and species concentration) with low uncertainty, spatial resolution corresponding to the span of the laser line of sight, and no supplemental sensor readings. The low uncertainty is provided by the broad spectral bandwidth, high resolution, and extremely well-known and controlled frequency axis of stabilized, mode-locked frequency combs. We demonstrate these capabilities in the isolator of a ground-test supersonic propulsion engine at Wright-Patterson Air Force Base. The mass flux measurements are consistent within 3.6% of the facility-level engine air supply values. A vertical scan of the laser beams in the isolator measures the spatially resolved mass flux, which is compared with computational fluid dynamics simulations. A rigorous uncertainty analysis demonstrates a DCS instrument uncertainty of ~0.4%, and total uncertainty (including non-instrument sources) of ~7% for mass flux measurements. These measurements demonstrate DCS as a low-uncertainty mass flux sensor for a variety of applications.Comment: Main Text: 15 pages, 7 figure; Supplement: 6 pages, 4 figures; Submitted to Optic

Simultaneous CH planar laser-induced fluorescence and particle imaging velocimetry in turbulent nonpremixed flames

=18600). Here, PLIF images reveal a CH layer of thickness typically <1 mm from flame base to tip. Furthermore, in these permanently blue flames, we observe instantaneous flamefront strain rates – derived from the PIV data – in excess of ±10 4  s -1 without flame extinction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42155/1/340-66-1-129_80660129.pd

Acetone laser induced fluorescence for low pressure/low temperature flow visualization

Acetone fluorescence provides a useful way to visualize the fluid mixing process within supersonic wind tunnels, some of which operate in the low temperature (240–300 K) and low pressure range (0.1–1 atm). Measurements are presented to quantify the dependence of the acetone laser induced fluorescence (LIF) signal on temperature and pressure in this range. The temperature and pressure sensitivity of the acetone LIF signal resulted in less than an 8% variation over the experimental conditions for a laser excitation wavelength of 266 nm. Condensation of the acetone vapor was identified as a potential problem for this diagnostic technique. Methods to prevent and check for condensation are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42176/1/348-28-5-471_00280471.pd