Numerical simulation of a three-dimensional chemical laser flow field including radiation produced by laser induced fluorescence

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6152805

Lankford, D W

Enhancing mixing of the gas streams has more than doubled the power from diffusion limited chemical lasers. This enhanced mixing was obtained by perturbing the laser cavity flow field by injecting jet streams into the flowing gases. A detailed understanding of this enhanced mixing process should lead to optimal laser design. Work reported in this dissertation has produced a time-dependent three-dimensional numerical solution of the Navier-Stokes equations capable of analyzing laser cavity flows with enhanced mixing due to injection jets, i.e. trip jets. Also developed was a numerical model of a new laser flow visualization technique, laser induced fluorescence (LIF). This model simulates the yellow, orange, and red radiation pattern produced by LIF when I/sub 2/ is used as a trace molecule. These numerical programs were used to analyze an experimental laser flow field. Results of the analysis compared well with measured pitot pressure scans and LIF photography. Details obtained from the numerical technique included the complete three-dimensional velocity, density, specie concentration, mach number, pressure, temperature, and energy fields. A detailed understanding of the mixing process in chemical lasers was obtained. The phenomena which increases the mixing in a laser cavity with trip jets is a distortion of the gas streams which increases the surface area across which diffusional mixing occurs.

• OSTI ID: 6152805
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
CHEMICAL LASERS
DIFFERENTIAL EQUATIONS
DIFFUSION
EQUATIONS
FLUID FLOW
FLUIDS
FLUORESCENCE
GASES
JETS
LASER CAVITIES
LASERS
LUMINESCENCE
MIXING
NAVIER-STOKES EQUATIONS
NUMERICAL SOLUTION
PARTIAL DIFFERENTIAL EQUATIONS
THREE-DIMENSIONAL CALCULATIONS
TIME DEPENDENCE