Chemical oxygen-iodine laser performance modeling

Yang, Tiankai; Copeland, Drew A.; Bauer, Arthur H.; Quan, Victor; McDermott, William E.; Cover, Ralph A.; Smith, D. M.

doi:10.2514/6.1997-2384

Cited by 20 publications

(7 citation statements)

References 8 publications

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“…Lampson et al 22;23 investigatedlaser beam quality issues with the MINT and OCELOT codes. Yang et al 24 have developedan ef cient approximatemethod to calculateCOIL performancequantitiesincludingiodine dissociation, excited-state pumping, quenching,and optical extraction from a stable resonator. Madden and Solomon 25 and Madden et al 26 have modeled the three-dimensionalchemically reacting ow eld of the COIL under nonlasingconditions,and, more recently,Madden et al have done so with theoretical power extraction.…”

Section: Introductionmentioning

confidence: 99%

Computation of Compressible Flows Through a Chemical Laser Device with Crossflow Injection

Miller

Shang

Tomaro

et al. 2001

Journal of Propulsion and Power

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The Air Force Research Laboratory has an ongoing effort to develop an accurate and ef cient computational tool to support the development of advanced chemical oxygen/iodine laser (COIL) devices. In this study, a series of computational simulations have been performed to provide a better understanding of uid dynamic phenomena within geometries associated with COIL ow elds. The parallel, implicit unstructured Navier-Stokes code Cobalt 60 was used to compute laminar, turbulent, and unsteady ows of helium within the research assessment and device improvement chemical laser (RADICL) nozzle. Computational results showing details of the jet mixing interaction and topological structure are presented. The laminar and turbulent results obtained with Cobalt 60 are in excellent agreement with measured mass ow rates and surface pressure data obtained from recent cold-ow tests performed with the RADICL device. Insuf cient experimental measurement prevents the determination of whether or not transition occurs within the injector region. The laminar time-accurate results indicate small-scale unsteadiness in the frequency range of 200 kHz downstream of the nozzle throat. Nomenclature A = cross-sectional area A, B, C, D = grid labels (D is nest grid) a = speed of sound a, b, c = viscous terms in energy equation [see Eq.(2)] c t1x , c t2x = x-direction convection terms for turbulence c t1 y , c t2 y = y-direction convection terms for turbulence c t1 z , c t2 z = z-direction convection terms for turbulence D = diameter of injector D = volumetric source term vector D t1 , D t 2 = source terms for turbulence closure equations dS = differential surface dV = differential volume E t = total energy, ½[e 1 2 .u 2 v 2 w 2 /] f , g, h = x, y, and z components of inviscid uxes i , j , k = Cartesian unit vectors k = thermal conductivity, turbulence kinetic energy M = Mach number M = molecular weight n = normal distance from wall n = molar ow rate n = unit normal vector p = pressure Q = vector of conserved variables Re = Reynolds number r; s; t = x, y, and z components of viscous uxes S = surface of control volume T = temperature t = time u, v, w = Cartesian components of velocity

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Section: Introductionmentioning

confidence: 99%

Computation of Compressible Flows Through a Chemical Laser Device with Crossflow Injection

Miller

Shang

Tomaro

et al. 2001

Journal of Propulsion and Power

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“…[8][9]. At high Mach number and low Reynolds number, flow mixing instability is difficult to develop.…”

Section: Introductionmentioning

confidence: 99%

“…It is known that for convective numbers of greater than approximately 0.6, mixing entrainment and mixing layer growth rate decrease from those of convective numbers of less than 0.5 (incompressible flow) by almost by a factor of 4 -5 [Refs. [8][9]. Complete oxygen-iodine/nitrogen mixing using parallel streams would require very large distances.…”

Section: Introductionmentioning

confidence: 99%

Advanced mixing nozzle concepts for COIL

Yang

Hsia

Moon

et al. 2000

Gas, Chemical, and Electrical Lasers and Intense Beam Control and Applications

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An advanced mixing nozzle concept has been developed for high chemical efficiency, high pressure recovery chemical oxygen-iodine laser applications. This concept incorporates the use of mixing tabs mounted at the nozzle exit plane for generating structured streamwise vorticity for mixing enhancement. The tab vortex generators produce strong streamwise vortices for mixing entrainment of highly compressible mixing layers. The optimal tab configuration, dimension, ramp angle relative to the flow direction, and tab spacing were determined by CFD analyses. The CFD computations show the entrainment and mixing produced by these mixing tabs are very efficient. The predicted mixing effectiveness of this nozzle configuration has been validated by experimental Pitot pressure scans of a three-blade nozzle hardware assembly.

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“…3 The exoergicity of the reaction (5) may suffice even to form electronically excited iodine atoms, I( 2 p1/ 2 ) with the branching ratio that was theoretically estimated' 5 up to the value of 0.5, however the experimental value obtained by using a high resolution Fourier transform spectrometer" 4 did not exceed the value of 0.005. The resultant efficiency of I atom production is influenced (in addition to the above loss-processes of F atoms) by the reactions which consume I atoms, the termolecular recombination of I atoms in the presence of buffer gas (He) and molecular iodine 16 …”

Section: Description Of Reaction Mechanismmentioning

confidence: 99%

Modeling of the chemical generation of atomic iodine in a chemical oxygen-iodine laser

Jirásek¹,

Špalek²,

Kodymová³

et al. 2002

Gas and Chemical Lasers and Intense Beam Applications III

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The mathematical modeling of reaction systems for chemical generation of atomic iodine is presented. This process can be applied in the chemical oxygen-iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. The parametric study of the production of atomic fluorine and subsequently atomic iodine in dependence on the pressure and dilution with inert gas was made. The calculation of the interaction between produced atomic iodine and singlet oxygen was made with four different mixing/reacting schemes.

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Chemical oxygen-iodine laser performance modeling

Cited by 20 publications

References 8 publications

Computation of Compressible Flows Through a Chemical Laser Device with Crossflow Injection

Computation of Compressible Flows Through a Chemical Laser Device with Crossflow Injection

Advanced mixing nozzle concepts for COIL

Modeling of the chemical generation of atomic iodine in a chemical oxygen-iodine laser

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