Laser Induced Temperature Rise In Semiconductors : Analytical Solutions, Application to the Transient

1983 ◽  
Vol 13 ◽  
Author(s):  
Alain Maruani ◽  
Y.I. Nissim ◽  
F. Bonnouvrier ◽  
D. Paquet
Keyword(s):  
Experimental Data ◽  
Analytical Solutions ◽  
Temperature Rise ◽  
Laser Heating ◽  
Integral Transforms ◽  
Surface Absorption ◽  
Cw Laser ◽  
Analytical Results ◽  
Good Agreement

ABSTRACTIt is shown how the systematic use of the method of integral transforms greatly simplifies the calculation of the temperature rises in laser irradiated media. In general, this method leads ultimately either to analytical results or to very simple numerical integrals (e.g. no poles, exponential kernels). We focus here on the analytical results, and discuss some aspects of CW laser heating, for large surface absorption, including radial dependance, depth dependance and transient nonlinearities. The new results derived in this treatment are in good agreement with experimental data from other studies.

Viscous Dissipation in Laminar Water Flows in Micro-Tubes

2007 ◽  
Author(s):  
In-Hwan Yang ◽  
Mohamed S. El-Genk
Keyword(s):  
Experimental Data ◽  
Viscous Dissipation ◽  
Temperature Rise ◽  
Experimental Results ◽  
Numerical Calculations ◽  
Analytical Expression ◽  
Water Flows ◽  
Good Agreement

Numerical calculations are performed to investigate the effect of viscous dissipation on the temperature rise and friction numbers for laminar water flows in micro-tubes. The calculated values are compared with those determined from reported experimental data for glass and diffused silica micro-tubes (D = 16 – 101 μm and L/D = 625 – 1479). The results confirm a definite slip at the wall with slip lengths of ∼ 0.7 μm and 1.0 μm, which decrease the friction number and the temperature rise in the micro-tubes, but their effect gradually diminishes as either D or L/D increases. The friction number decreases exponentially as D decreases and, to a lesser extent, as L/D increases. The effect of L/D on the friction number is insignificant for micro-tube diameters ≤ 20 μm. For D > 400 μm, the friction number approaches that of Hagen-Posieuille of 64 for macro-tubes when L/D > 1500, but approaches higher values at smaller L/D. The dimensionless analytical expression developed for calculating the friction number and the temperature rise for water flows in micro-tubes is in good agreement with both the numerical and experimental results.

Friction Numbers and Viscous Dissipation Heating for Laminar Flows of Water in Microtubes

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Mohamed S. El-Genk ◽  
In-Hwan Yang
Keyword(s):  
Experimental Data ◽  
Aspect Ratio ◽  
Viscous Dissipation ◽  
Temperature Rise ◽  
Strong Dependence ◽  
Velocity Slip ◽  
Laminar Flows ◽  
Water Flows ◽  
Aspect Ratios ◽  
Good Agreement

The friction numbers for laminar flows of water in microtubes, determined from the temperature rise due to the viscous dissipation heating assuming a velocity slip, show a strong dependence on the diameter and aspect ratio. The calculated values compare well with those determined from experimental data for water flows in glass and diffused silica microtubes (16–101μm in diameter D and aspect ratios L∕D=499–1479). With a slip, the friction number almost exponentially decreases as D decreases and, to a lesser extent, as L∕D increases. For D>400μm, the friction number approaches the theoretical Hagen–Poiseuille for macrotubes (64) when L∕D>∼1500, but higher values at smaller L∕D. The developed semiempirical analytical expression for calculating the friction number is in good agreement with the numerical and experimental results. The results suggest the presence of a velocity slip in the experiments and the plausible presence of a thin nanolayer at the walls of the microtubes. For D>200μm, this layer, if exists, is estimated to be ∼18.9nm, but increases to ∼21.5nm for D<200μm, when R¯e=800 and L∕D=1479.

An Investigation of Ejector Design by Analysis and Experiment

1950 ◽  
Vol 17 (3) ◽  
pp. 299-309
Author(s):  
J. H. Keenan ◽  
E. P. Neumann ◽  
F. Lustwerk
Keyword(s):  
Experimental Data ◽  
Constant Pressure ◽  
Jet Pump ◽  
Pump Design ◽  
One Dimensional ◽  
Analytical Results ◽  
Constant Area ◽  
Jet Pumps ◽  
Good Agreement

Abstract A one-dimensional method of analysis of jet pumps or ejectors is presented. The analysis considers mixing of the primary and secondary streams at constant pressure, and mixing of the streams at constant area. For the analytical conditions considered, better performance can be obtained when constant-pressure mixing is employed. A comparison between experimental and analytical results shows good agreement over a broad range of variables. Some experimental data on the length of tube required for mixing of the two streams are presented. A method for jet-pump design is given.

Experiment and Analysis of Instability of Tube Rows Subject to Liquid Crossflow

1982 ◽  
Vol 49 (4) ◽  
pp. 704-709 ◽  
Author(s):  
S. S. Chen ◽  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Data ◽  
Analytical Study ◽  
Displacement Mechanism ◽  
Analytical Results ◽  
Damping Parameter ◽  
Good Agreement

A tube array subjected to crossflow may become unstable by either one or both of the two basic mechanisms: velocity mechanism and displacement mechanism. An experimental and analytical study of tube rows in liquid crossflow is performed to verify the existence and transition between the two mechanisms at the intermediate values of mass-damping parameter. Experimental data and analytical results are found to be in good agreement.

scholarly journals EXTENDED BOUSSINESQ EQUATIONS FOR WAVES IN TWO POROUS LAYERS

2018 ◽  
pp. 92
Author(s):  
Changhoon Lee ◽  
Van Nghi Vu ◽  
Tae-Hwa Jung ◽  
Thanh Thu Huynh
Keyword(s):  
Experimental Data ◽  
Porous Layer ◽  
Analytical Solutions ◽  
Water Waves ◽  
Royal Society ◽  
Boussinesq Equations ◽  
Water Layer ◽  
Boussinesq Model ◽  
Porous Layers ◽  
Good Agreement

In this study we continue the work of Vu et al. (2018) [Coastal Eng. 139, 85-97] to develop an extended Boussinesq model that predicts the propagation of water waves in two porous layers. The first and second layer can be a water layer or a porous layer. The inertial and drag resistances are considered in the developed model. After being successfully validated against the analytical solutions, the model is used to simulate waves propagating over a submerged triangular porous bar. The numerical results show good agreement with the physical experimental data of Hsiao et al. (1998) [Proc. Royal Society of London A 458, 1291-1322].

A Study of Feedback Fluid Jet Oscillator With a Supersonic Power Jet: Part II: Analytical Study of Its Characteristics

1973 ◽  
Vol 95 (2) ◽  
pp. 185-190 ◽  
Author(s):  
J. D. McGeachy ◽  
W. L. Chow
Keyword(s):  
Experimental Data ◽  
Steady Flow ◽  
Analytical Study ◽  
Oscillator Model ◽  
General Behavior ◽  
Analytical Results ◽  
Flow Phenomena ◽  
Good Agreement

The study of the flow phenomena occurring within a feedback fluidic jet oscillator (see reference [2]) was continued on the basis of the quasi-steady flow concept. Description and explanation of these phenomena throughout the oscillating cycle were possible in view of the reasonably good agreement between the analytical results and experimental data. The characteristic pressures within the system prior to switching can be correlated and predicted. For a particular oscillation geometry, the required primary pressure to start jet switching and oscillation can also be estimated. A simplified oscillator model has also been suggested to illustrate the general behavior of such a feedback oscillator.

CFD Analysis of Gas-Insulated Transformers

2004 ◽  
Author(s):  
D. J. Lee ◽  
S. S. Seol ◽  
I. S. Park ◽  
J. H. Kim ◽  
S. B. Shin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Design Process ◽  
Temperature Rise ◽  
Empirical Formula ◽  
Pressure Loss ◽  
Thermal Design ◽  
Cfd Analysis ◽  
Empirical Formulas ◽  
Loss Of Coolant ◽  
Good Agreement

A thermal design of transformers has been performed using an empirical formula. In order to reduce the developing cost and time, CFD analysis is used in thermal design process for gas-insulated transformers. We calculated the pressure loss of coolant and the temperature rise of winding with empirical formulas and CFD analysis. Also, we constructed some real machines and compared the analytic results with the experimental data. The comparison shows a good agreement between the CFD calculations and experimental results.

Numerical Simulations of Hydraulic Jumps in Water Sloshing and Water Impacting

2001 ◽  
Vol 124 (1) ◽  
pp. 215-226 ◽  
Author(s):  
Tzung-hang Lee ◽  
Zhengquan Zhou ◽  
Yusong Cao
Keyword(s):  
Experimental Data ◽  
Numerical Simulations ◽  
Shallow Water ◽  
Numerical Investigation ◽  
Analytical Solutions ◽  
Water Reservoir ◽  
Hydraulic Jumps ◽  
Dam Breaking ◽  
Water Problems ◽  
Good Agreement

A numerical investigation on Glimm’s method as applied to water sloshing and impacting is carried out. Emphasis is given to the handling and predicting hydraulic jumps. The effects of the spatial and temporal discretizations are examined. Three shallow water problems, 1) dam-breaking problem, 2) water sloshing in a rolling tank, and 3) impact of breaking of a water reservoir, are studied. It is shown numerically that Glimm’s method is stable and converged solutions can be obtained. The characteristics of the hydraulic jumps are well captured by the numerical calculations. The numerical results are in good agreement with either analytical solutions or experimental data.

scholarly journals TRANSIENTS IN CW LASER HEATING OF SEMICONDUCTORS : GENERAL METHOD, ANALYTICAL SOLUTIONS AND ILLUSTRATIONS

1983 ◽  
Vol 44 (C5) ◽  
pp. C5-87-C5-90
Author(s):  
A. Maruani ◽  
Y. I. Nissim ◽  
F. Bonnouvrier ◽  
D. Paquet
Keyword(s):  
Analytical Solutions ◽  
Laser Heating ◽  
Cw Laser ◽  
General Method
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