A numerical study on the effects of viscosity on the performance of CO/sub 2/ gasdynamic laser

Technical Report · Sun Jun 01 04:00:00 EDT 1975

OSTI ID:7251463

Kawamura, R; Masuda, W

The effects of viscosity on the performance of CO/sub 2/ gasdynamic laser were studied numerically using the laminar boundary layer model and turbulent wake model. A finite-difference method was developed for the solution of the vibrational nonequilibrium boundary layer equations. To avoid the numerical instability associated with the very fast relaxation rates, production terms in the differential equations were linearized about an appropriate initial guess to the solutions, and an implicit finite-difference scheme of Crank-Nicolson type was used to solve the resulting equations. Solutions were obtained by successively solving the equations in sequence until the original differential equations, in which the production terms are expressed as nonlinear, are satisfied within the desired accuracy. The effects of the nozzle wall conditions, specifically the wall temperature and catalysis, reservoir conditions and the throat Reynolds number on the performance of CO/sub 2/ gasdynamic laser were studied. The numerical results show that the viscosity is an important parameter for determining the optimum nozzle size and that one should operate CO/sub 2/ gasdynamic lasers with uniformly cooled wall condition.

• Research Organization: Tokyo Univ. (Japan)
• OSTI ID: 7251463
• Report Number(s): N-75-29408; ISAS-528(Vol.40-No.8)
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
CARBON DIOXIDE LASERS
GAS LASERS
LASERS
NOZZLES
PERFORMANCE