Effects of imaging system blur on measurements of flow scalars and scalar gradients

Analysis of flame surface density measurements in turbulent premixed combustion

“…With the smallest pattern resolved, both vertical and horizontal MTFs (modulation transfer functions) are higher than the criteria given by Wang and Clemens [19]. From this information, one can assume that the pixel projection is close to the real resolution (i.e., 0.11 mm/pixel).…”

Simultaneous Rayleigh temperature, OH- and CH2O-LIF imaging of methane jets in a vitiated coflow

“…This camera has 1280 × 1024 pixels with individual pixel sizes of 6.7 µm × 6.7 µm and a quantum efficiency (QE) of 36% at 532 nm. The Rayleigh imaging system step response function (SRF) was measured using the scanning knife edge method outlined by Wang and Clemens [11] and references contained within. From the SRF the line spread function (LSF) was calculated and a FWHM of 40 µm was predicted.…”

The structure of premixed and stratified low turbulence flames

“…The optical resolution was determined primarily by the pair of achromatic lenses at the front end of the collection system. The measured line-spread function at best focus was $40 lm FWHM for each system at fixed wavelength, using a knife edge method [40]. Final focusing of each camera was accomplished using a laser-drilled target with a linear pattern of 50 lm holes on 200 lm centers, located on the plane bisecting the laser alignment aperture.…”