Experimental study of cutting thick aluminum and steel with a chemical oxygen-iodine laser using an N 2 or O 2 gas assist

Carroll, David L.; Rothenflue, James A.

doi:10.1117/12.270182

Cited by 6 publications

(3 citation statements)

References 7 publications

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“…Although laser cutting is nowadays a well-established sheet metal processing method, still a lot of fundamental research is ongoing, which focuses among others on the cutting of thick plates (> 15mm) [1,2,3,4]. A very significant trend that could be witnessed in recent years is the increase of the laser power, driven by the demand to increase the thickness of plates that can be processed.…”

Section: Introductionmentioning

confidence: 99%

Methods for Monitoring of Laser Cutting by Means of Acoustic and Photodiode Sensors

Keuster

Duflou

Kruth

2005

AMR

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Laser cutting is a well-established sheet metal processing method. Nowadays a trend towards the cutting of thick plates (> 15 mm) can be observed. However for these thick plates the process window in which good cutting results can be obtained is more narrow compared to that for thin sheets due to the very difficult balance to be found between the different process parameters. Even after determination of the process window, a good cutting quality cannot always be guaranteed. Therefore cutting of thick plates is still characterized by a large scrap percentage, which impedes a breakthrough to large scale industrial use. A solution to this problem is to incorporate a sensor system in the laser cutting machine that monitors the cut quality on-line. This monitoring system could then be integrated in a process control system, which adapts the process parameters in function of the observed cut quality in real time. In this way a good cut quality could always be guaranteed. In this study, the first step in this direction, the determination of an appropriate monitoring system, is dealt with. The applicability for monitoring purposes of two types of sensors is investigated: a microphone and a photodiode. For both types, correlation between the sensor output and the cut quality is investigated in a qualitative way. The scope of the reported research was not limited to contour cutting, also piercing is covered in the study.

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Section: Introductionmentioning

confidence: 99%

Methods for Monitoring of Laser Cutting by Means of Acoustic and Photodiode Sensors

Keuster

Duflou

Kruth

2005

AMR

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“…The Reynolds number for this case based on measured subsonic conditions, 41 sonic conditions at the throat, and a throat height of 0.889 cm is 4:1 10 3 . For all of the computations in this study, the Prandtl number was 0.68, and the ratio of speci c heats°was 5 3 . All steady-state computations were done with the temporal damping coef cients set to 0.15 and 0.05 for the inviscid and viscous terms, respectively.…”

Section: A 9257cf11: Steady-state Laminarmentioning

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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“…1 Since it has many advantageous attributes such as short fiber deliverable wavelength, scalable continuous wave power, and excellent material interaction properties, COIL is seen as one kind of the most important chemical laser. 2,3 The singlet oxygen generator (SOG) is the key component of the COIL which provides chemical energy. Though COIL has seen rapid development since its invention, SOG still remains a challenge.…”

Section: ■ Introductionmentioning

confidence: 99%

Experiment and Simulation on a New Swirl-Jet-Type Singlet Oxygen Generator

Liu

Chen

2013

Ind. Eng. Chem. Res.

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The singlet oxygen generator (SOG) is the heart of chemical oxygen iodine laser. A new swirl-jet-type SOG was proposed which consists of a reaction part and a separation part. Planar laser-induced fluorescence combined with maximum entropy method were used to study the droplet size distribution, and a modified Muschelknautz model and Computational Fluid Dynamics were used to simulate the separation efficiency of vapor and liquid phases. The results of the net reaction predict 99.2% conversion of chlorine and 42.2% yield of singlet oxygen, demonstrating the superiority of the new type of SOG.

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Experimental study of cutting thick aluminum and steel with a chemical oxygen-iodine laser using an N 2 or O 2 gas assist

Cited by 6 publications

References 7 publications

Methods for Monitoring of Laser Cutting by Means of Acoustic and Photodiode Sensors

Methods for Monitoring of Laser Cutting by Means of Acoustic and Photodiode Sensors

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

Experiment and Simulation on a New Swirl-Jet-Type Singlet Oxygen Generator

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