A Multiscale Simulation Approach for the MOCVD of GaN Using a Single-Molecule Precursor in a Vertical Stagnation Flow Reactor

2005 ◽  
Vol 11 (6-7) ◽  
pp. 306-316 ◽  
Author(s):  
M. Mukinovic ◽  
G. Brenner ◽  
J. Khanderi ◽  
S. Spöllmann ◽  
R. A. Fischer ◽  
...  
Keyword(s):  
Single Molecule ◽  
Flow Reactor ◽  
Multiscale Simulation ◽  
Simulation Approach ◽  
Stagnation Flow

Flow Structure and Heat Transfer in Stagnation Flow CVD Reactor

2010 ◽  
Author(s):  
Nasir Memon ◽  
Yogesh Jaluria
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Atmospheric Pressure ◽  
Gas Flow ◽  
Flow Reactor ◽  
Chemical Vapor ◽  
Design Parameters ◽  
Stagnation Flow ◽  
Inlet Length ◽  
The Impact

An experimental study is undertaken to investigate the flow structure and heat transfer in a stagnation flow Chemical Vapor Deposition (CVD) reactor at atmospheric pressure. It is critical to develop models that predict flow patterns in such a reactor to achieve uniform deposition across the substrate. Free convection can negatively affect the gas flow as cold inlet gas impinges on the heated substrate, leading to vortices and disturbances in the normal flow path. This experimental research will be used to understand the buoyancy-induced and momentum-driven flow structure encountered in an impinging jet CVD reactor. Investigations are conducted for various operating and design parameters. A modified stagnation flow reactor is built where the height between the inlet and substrate is reduced when compared to a prototypical stagnation flow reactor. By operating such a reactor at certain Reynolds and Grashof numbers it is feasible to sustain smooth and vortex free flow at atmospheric pressure. The modified stagnation flow reactor is compared to other stagnation flow geometries with either a varied inlet length or varied heights between the inlet and substrate. Comparisons are made to understand the impact of such geometric changes on the flow structure and the thermal boundary layer. In addition, heat transfer correlations are obtained for the substrate temperature. Overall, the results obtained provide guidelines for curbing the effects of buoyancy and for improving the flow field to obtain greater film uniformity when operating a stagnation flow CVD reactor at atmospheric pressure.

scholarly journals A Multiscale Simulation Approach to Modeling Drug–Protein Binding Kinetics

2018 ◽  
Vol 14 (11) ◽  
pp. 6093-6101 ◽  
Author(s):  
Susanta Haldar ◽  
Federico Comitani ◽  
Giorgio Saladino ◽  
Christopher Woods ◽  
Marc W. van der Kamp ◽  
...  
Keyword(s):  
Protein Binding ◽  
Multiscale Simulation ◽  
Binding Kinetics ◽  
Simulation Approach ◽  
Protein Binding Kinetics ◽  
Drug Protein Binding

scholarly journals Combining Planar Laser-Induced Fluorescence with Stagnation Point Flows for Small Single-Crystal Model Catalysts: CO Oxidation on a Pd(100)

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 484 ◽  
Author(s):  
Jianfeng Zhou ◽  
Sebastian Matera ◽  
Sebastian Pfaff ◽  
Sara Blomberg ◽  
Edvin Lundgren ◽  
...  
Keyword(s):  
Single Crystal ◽  
Co Oxidation ◽  
Flow Reactor ◽  
Laser Induced Fluorescence ◽  
Model Catalysts ◽  
Stagnation Flow ◽  
Reaction Conditions ◽  
Planar Laser Induced Fluorescence ◽  
Planar Laser ◽  
Crystal Model

A stagnation flow reactor has been designed and characterized for both experimental and modeling studies of single-crystal model catalysts in heterogeneous catalysis. Using CO oxidation over a Pd(100) single crystal as a showcase, we have employed planar laser-induced fluorescence (PLIF) to visualize the CO2 distribution over the catalyst under reaction conditions and subsequently used the 2D spatially resolved gas phase data to characterize the stagnation flow reactor. From a comparison of the experimental data and the stagnation flow model, it was found that characteristic stagnation flow can be achieved with the reactor. Furthermore, the combined stagnation flow/PLIF/modeling approach makes it possible to estimate the turnover frequency (TOF) of the catalytic surface from the measured CO2 concentration profiles above the surface and to predict the CO2, CO and O2 concentrations at the surface under reaction conditions.

In Situ Diagnostics and Modeling of Methane Catalytic Partial Oxidation on Pt in a Stagnation-Flow Reactor

2003 ◽  
Vol 42 (25) ◽  
pp. 6559-6566 ◽  
Author(s):  
Joshua D. Taylor ◽  
Mark D. Allendorf ◽  
Anthony H. McDaniel ◽  
Steven F. Rice
Keyword(s):  
Partial Oxidation ◽  
Flow Reactor ◽  
Catalytic Partial Oxidation ◽  
Stagnation Flow ◽  
In Situ Diagnostics

Multiscale Simulation of Porous Quasi-Brittle Ceramics Fracture

2015 ◽  
Vol 756 ◽  
pp. 196-204 ◽  
Author(s):  
Vladimir V. Skripnyak ◽  
Evgeniya G. Skripnyak ◽  
Vladimir A. Skripnyak ◽  
Irina K. Vaganova ◽  
Anatoly M. Bragov ◽  
...  
Keyword(s):  
Shock Wave ◽  
Brittle Fracture ◽  
Strain Rate ◽  
Brittle Failure ◽  
Dynamic Compression ◽  
Theoretical Data ◽  
Multiscale Simulation ◽  
Simulation Approach ◽  
Ultra High Temperature Ceramics ◽  
Nanostructured Ceramics

Multiscale computer simulation approach has been applied to research mechanisms of failure in ceramic nanostructured ceramics under dynamic loading. The obtained experimental and theoretical data indicate quasi-brittle fracture of nanostructured ZrB2 ceramics under dynamic compression and tension. Damage nucleation and accumulation in quasi brittle nanostructured ceramics were simulated under impact loadings. Fracture of nanostructured ultra-high temperature ceramics under pulse and shock-wave loadings is provided by fast processes of intercrystalline brittle fracture and relatively slow processes of quasi-brittle failure via growth and coalescence of opened microcracks. For nanostructures ZrB2 ceramics with porosity of 7 %, the compressive strength at strain rate of 1800 s-1 is equal to 2440±50 MPa, the tensile strength at strain rate of 300 s-1 is equal to 155±20 MPa.

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