An Accurate Experimental Method for Determining the Injectant Mass Fraction Distribution in a Supersonic Turbulent Flow Mixing Region

2006 ◽  
Author(s):  
Alexander Gonor ◽  
Vitali Khaikine ◽  
James Gottlieb ◽  
Isaiah Blankson
Keyword(s):  
Turbulent Flow ◽  
Experimental Method ◽  
Mass Fraction ◽  
Flow Mixing ◽  
Fraction Distribution

Mass transfer dominated by thermal diffusion in laminar boundary layers

1997 ◽  
Vol 336 ◽  
pp. 379-409 ◽  
Author(s):  
PEDRO L. GARCÍA-YBARRA ◽  
JOSE L. CASTILLO
Keyword(s):  
Mass Transport ◽  
Boundary Layers ◽  
Thermal Diffusion ◽  
Mass Fraction ◽  
Soret Effect ◽  
Second Order ◽  
Brownian Diffusion ◽  
Diffusion Transport ◽  
Laminar Boundary Layers ◽  
Fraction Distribution

The concentration distribution of massive dilute species (e.g. aerosols, heavy vapours, etc.) carried in a gas stream in non-isothermal boundary layers is studied in the large-Schmidt-number limit, Sc[Gt ]1, including the cross-mass-transport by thermal diffusion (Ludwig–Soret effect). In self-similar laminar boundary layers, the mass fraction distribution of the dilute species is governed by a second-order ordinary differential equation whose solution becomes a singular perturbation problem when Sc[Gt ]1. Depending on the sign of the temperature gradient, the solutions exhibit different qualitative behaviour. First, when the thermal diffusion transport is directed toward the wall, the boundary layer can be divided into two separated regions: an outer region characterized by the cooperation of advection and thermal diffusion and an inner region in the vicinity of the wall, where Brownian diffusion accommodates the mass fraction to the value required by the boundary condition at the wall. Secondly, when the thermal diffusion transport is directed away from the wall, thus competing with the advective transport, both effects balance each other at some intermediate value of the similarity variable and a thin intermediate diffusive layer separating two outer regions should be considered around this location. The character of the outer solutions changes sharply across this thin layer, which corresponds to a second-order regular turning point of the differential mass transport equation. In the outer zone from the inner layer down to the wall, exponentially small terms must be considered to account for the diffusive leakage of the massive species. In the inner zone, the equation is solved in terms of the Whittaker function and the whole mass fraction distribution is determined by matching with the outer solutions. The distinguished limit of Brownian diffusion with a weak thermal diffusion is also analysed and shown to match the two cases mentioned above.

scholarly journals Experimental Method for Wind Tunnel Tests to Simulate Turbulent Flow on the Roof of High-speed Trains

2012 ◽  
Vol 53 (3) ◽  
pp. 167-172 ◽  
Author(s):  
Takehisa TAKAISHI ◽  
Mitsuru IKEDA
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flow ◽  
Experimental Method ◽  
High Speed ◽  
Wind Tunnel Tests ◽  
High Speed Trains

A Numerical Study of Heat Transfer and Flow Structure in Channels With Miniature V Rib-Dimple Hybrid Structure on One Wall

2018 ◽  
Author(s):  
Peng Zhang ◽  
Yu Rao ◽  
Yanlin Li
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Hybrid Structure ◽  
Transfer Enhancement ◽  
Nusselt Numbers ◽  
Flow And Heat Transfer ◽  
Flow Mixing

This paper presents a numerical study on turbulent flow and heat transfer in the channels with a novel hybrid cooling structure with miniature V-shaped ribs and dimples on one wall. The heat transfer characteristics, pressure loss and turbulent flow structures in the channels with the rib-dimples with three different rib heights of 0.6 mm, 1.0 mm and 1.5 mm are obtained for the Reynolds numbers ranging from 18,700 to 60,000 by numerical simulations, which are also compared with counterpart of a pure dimpled and pure V ribbed channel. The results show that the overall Nusselt numbers of the V rib-dimple channel with the rib height of 1.5 mm is up to 70% higher than that of the channels with pure dimples. The numerical simulations show that the arrangement of the miniature V rib upstream each dimple induces complex secondary flow near the wall and generates downwashing vortices, which intensifies the flow mixing and turbulent kinetic energy in the dimple, resulting in significant improvement in heat transfer enhancement and uniformness.

A New Approach Based on Utilization of the Static and Pitot Probes for Determination of an Injectant Mass Fraction Distribution at Turbulent Mixing

2005 ◽  
Author(s):  
Alexander Gonor ◽  
Mikhail Gilinsky ◽  
Vitali Khaikine ◽  
James Gottlieb ◽  
Isaiah Blankson
Keyword(s):  
Turbulent Mixing ◽  
Mass Fraction ◽  
New Approach ◽  
Fraction Distribution ◽  
Pitot Probes

scholarly journals An Experimental Method of 2-D Two-Phase Flow. (Measurement of Void Fraction Distribution Using Image Processing).

1991 ◽  
Vol 57 (538) ◽  
pp. 1979-1984 ◽  
Author(s):  
Yoshifusa SATO ◽  
Michio SADATOMI ◽  
Akimaro KAWAHARA ◽  
Shinji ASAKURA
Keyword(s):  
Image Processing ◽  
Experimental Method ◽  
Void Fraction ◽  
Flow Measurement ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Void Fraction Distribution ◽  
Fraction Distribution

A Two-Dimensional Turbulent-Flow Mixing Model for Parallel-Flow Rod Bundles

1968 ◽  
Vol 32 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Phillip A. Lowe
Keyword(s):  
Turbulent Flow ◽  
Mixing Model ◽  
Parallel Flow ◽  
Two Dimensional ◽  
Rod Bundles ◽  
Flow Mixing

scholarly journals Effects of Pulse Interval and Dosing Flux on Cells Varying the Relative Velocity of Micro Droplets and Culture Solution

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 119 ◽  
Author(s):  
Zhanwei Wang ◽  
Kun Liu ◽  
Jiuxin Ning ◽  
Shulei Chen ◽  
Ming Hao ◽  
...  
Keyword(s):  
Diffusion Process ◽  
Mass Fraction ◽  
Pulse Interval ◽  
Culture Solution ◽  
Cell Surfaces ◽  
Fraction Distribution ◽  
Pdms Chip ◽  
Solution Velocity ◽  
The Mathematical Model ◽  
Delivery Efficiency

Microdroplet dosing to cell on a chip could meet the demand of narrow diffusion distance, controllable pulse dosing and less impact to cells. In this work, we studied the diffusion process of microdroplet cell pulse dosing in the three-layer sandwich structure of PDMS (polydimethylsiloxane)/PCTE (polycarbonate) microporous membrane/PDMS chip. The mathematical model is established to solve the diffusion process and the process of rhodamine transfer to micro-traps is simulated. The rhodamine mass fraction distribution, pressure field and velocity field around the microdroplet and cell surfaces are analyzed for further study of interdiffusion and convective diffusion effect. The cell pulse dosing time and drug delivery efficiency could be controlled by adjusting microdroplet and culture solution velocity without impairing cells at micro-traps. Furthermore, the accuracy and controllability of the cell dosing pulse time and maximum drug mass fraction on cell surfaces are achieved and the drug effect on cells could be analyzed more precisely especially for neuron cell dosing.

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