One-dimensional improvement and two-dimensional and 3-dimensional treatments for stable oscillation condition, mode structure and power output in high-speed-flow lasers

For high-speed-flow lasers, the one-dimensional and first-order approximate treatment in[1] under approximation of geometrical optics is improved still within the scope of approx-imation of geometrical optics. The strict accurate results are obtained, and what is more,two- and three-dimensional treatments are done. Thus for two- and three-dimensional cases, thestable oscillation condition, the formulae of power output and analytical expression of modesunder approximation of geometrical optics (in terms of gain function) are derived. Accord-ing to the present theory, one-and two-dimensional calculations for the typical case of Gerry'sexperiment are presented. All the results coincide well with the experiment and are better thanthe results obtained in [1].In addition, the applicable scope of Lee's stable oscillation condition given by [1] is ex-panded; the condition for the approximation of gcometrical optics to be applied to mode con-structure in optical cavity is obtained for the first time and the difference between thiscondition and that for free space is also pointed out in the present work.

Kinetic model of continuous-wave flow chemical lasers

In this paper an analysis of the kinetic theory of the continuous-wave flow chemical lasers(CWFCL) is presented with emphasis being laid on the effects of inhomogeneous broadeningon CWFCL's performance. The results obtained are applicable to the case where laser fre-quency is either coincident or incoincident with that of the eenter of the line shape. This rela-tion has been,compared with that of the rate model in common use. These two models are almostidentical as the broadening parameter η is larger than 1. The smaller the value of η, thegreater the difference between the results of these two models will be. For fixed η, the dif-ferences between fhe results of the two models increase with the increase of the frequencyshift parameter ξ. When η is about less than 0.2. the kinetic model can predict exactly the in-homogeneous broadening effects,while the rate model cannot.

Flow pattern in chandler loop - the artificial thrombus formation

In this paper a hydrodynamic approach is used to analyse carefully the flow field inChandler loop--the artificial thrombus formation. The results obtained show that near thelower meniscus where the thrombus is formed, there is a back flow accompanied with asecondary flow and its mainflow is toward the meniscus, thus providing a favourable condi-tion for corpuscle aggregation. Our finding is valuable for studying the mechanism ofthrombus formation in artificial organ and in vivo.

Coupled deformation-flow analysis for methane hydrate production by depressurized wells

A formulation for coupled flow-deformation analysis of methane-hydrate extraction problems is presented. By assuming that the hydrate does not flow, a two phase flow formulation is considered, based on Darcy's law and capillary pressure relation. The formulation is implemented in the finite difference code FLAC. The code was used to investigate the stability of a methane extraction well by depressurizing the well. © 2005 Taylor & Francis Group, London.