کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1784512 1023263 2012 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modeling midwave infrared muzzle flash spectra from unsuppressed and flash-suppressed large caliber munitions
موضوعات مرتبط
مهندسی و علوم پایه فیزیک و نجوم فیزیک اتمی و مولکولی و اپتیک
پیش نمایش صفحه اول مقاله
Modeling midwave infrared muzzle flash spectra from unsuppressed and flash-suppressed large caliber munitions
چکیده انگلیسی

Time-resolved infrared spectra of firings from a 152 mm howitzer were acquired over an 1800–6000 cm−1 spectral range using a Fourier-transform spectrometer. The instrument collected primarily at 32 cm−1 spectral and 100 Hz temporal resolutions. Munitions included unsuppressed and chemically flash suppressed propellants. Secondary combustion occurred with unsuppressed propellants resulting in flash emissions lasting ∼100 ms and dominated by H2O and CO2 spectral structure. Non-combusting plume emissions were one-tenth as intense and approached background levels within 20–40 ms. A low-dimensional phenomenological model was used to reduce the data to temperatures, soot absorbances, and column densities of H2O, CO2, CH4, and CO. The combusting plumes exhibit peak temperatures of ∼1400 K, areas of greater than 32 m2, low soot emissivity of ∼0.04, with nearly all the CO converted to CO2. The non-combusting plumes exhibit lower temperatures of ∼1000 K, areas of ∼5 m2, soot emissivity of greater than 0.38 and CO as the primary product. Maximum fit residual relative to peak intensity are 14% and 8.9% for combusting and non-combusting plumes, respectively. The model was generalized to account for turbulence-induced variations in the muzzle plumes. Distributions of temperature and concentration in 1–2 spatial regions demonstrate a reduction in maximum residuals by 40%. A two-region model of combusting plumes provides a plausible interpretation as a ∼1550 K, optically thick plume core and ∼2550 K, thin, surface-layer flame-front. Temperature rate of change was used to characterize timescales and energy release for plume emissions. Heat of combustion was estimated to be ∼5 MJ/kg.


► Time-resolved infrared muzzle flash spectra from a large caliber gun are reported.
► Radiative transfer models are used to estimate physical properties from the spectra.
► Combustion emissions are dominated by H2O and CO2 at 1200–1600 K.
► Non-combusting plumes are primarily particulates, soot, and CO at 850–1050 K.
► Temperature rate of change is used to estimate heat of combustion of the propellant.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Infrared Physics & Technology - Volume 55, Issue 4, July 2012, Pages 246–255
نویسندگان
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