scholarly journals Mass Transfer Related to Heterogeneous Combustion of Solid Carbon in the Forward Stagnation Region - Part 1 - Combustion Rate and Flame Structure

10.5772/22761 ◽  
2011 ◽  
Author(s):  
Atsushi Makino
Keyword(s):  
Mass Transfer ◽  
Combustion Rate ◽  
Flame Structure ◽  
Heterogeneous Combustion ◽  
Solid Carbon ◽  
Stagnation Region

Local Heat/Mass Transfer Measurement on the Effusion Plate in Impingment/Effusion Cooling System

2000 ◽  
Author(s):  
Hyung Hee Cho ◽  
Dong Ho Rhee
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Cooling System ◽  
Perforated Plate ◽  
Local Heat ◽  
Impinging Jets ◽  
Transfer Coefficients ◽  
Stagnation Region ◽  
Perforated Plates ◽  
Flow Acceleration

The present study is conducted to investigate the local heat/mass transfer characteristics for flow through perforated plates. A naphthalene sublimation method is employed to determine the local heat/mass transfer coefficients on the effusion plate. Two parallel perforated plates are arranged in two different configurations: staggered and shifted in one direction. The experiments are conducted for hole pitch-to-diameter ratios of 6.0, for gap distance between the perforated plates of 0.33 to 10 hole diameters, and for Reynolds numbers of 5,000 to 12,000. The result shows that the high transfer region is formed at stagnation region and at the mid-line of the adjacent impinging jets due to secondary vortices and flow acceleration to the effusion hole. For flows through the perforated plates, the mass transfer rates on the surface of the effusion plate are about six to ten times higher than for effusion cooling alone (single perforated plate). In general, higher heat/mass transfer is obtained with smaller gap distance between two perforated plates.

scholarly journals Surface Injection Effect on Mass Transfer From a Cylinder in Crossflow: A Simulation of Film Cooling in the Leading Edge Region of a Turbine Blade

1990 ◽  
Vol 112 (3) ◽  
pp. 418-427 ◽  
Author(s):  
J. Karni ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Turbine Blade ◽  
Film Cooling ◽  
Leading Edge ◽  
Edge Region ◽  
Stagnation Region ◽  
Stagnation Line ◽  
Naphthalene Sublimation Technique ◽  
Circular Holes ◽  
Cooling Effects

A naphthalene sublimation technique is used to study the effect of surface injection on the mass (heat) transfer from a circular cylinder in crossflow. Using a heat/mass transfer analogy the results can be used to predict film cooling effects in the leading edge region of a turbine blade. Air injection through one row of circular holes is employed in the stagnation region of the cylinder. Streamwise and spanwise injection inclinations are studied separately, and the effects of blowing rate and injection location relative to the cylinder front stagnation line are investigated. Streamwise injection produces significant mass transfer increases downstream of the injection holes, but a relatively small increase is observed between holes, normal to the injection direction. The mass transfer distribution, measured with spanwise injection through holes located near the cylinder front stagnation line, is extremely sensitive to small changes in the injection hole location relative to stagnation. When the centers of the spanwise injection holes are located 5 deg or more from the stagnation line, the holes lie entirely on one side of the stagnation line and the injection affects the mass transfer only on that side of the cylinder, approaching the pattern observed with streamwise injection.

Effect of Rotation on Heat/Mass Transfer for an Impingement/Effusion Cooling System

2007 ◽  
Author(s):  
Sung Kook Hong ◽  
Hyung Hee Cho
Keyword(s):  
Mass Transfer ◽  
Heat Mass Transfer ◽  
Cooling System ◽  
Local Heat ◽  
Hole Diameter ◽  
Transfer Coefficients ◽  
Stagnation Region ◽  
Plate Spacing ◽  
Jet Cooling ◽  
Flow Mixing

The purpose of this study is to investigate the effect of rotation on the heat/mass transfer in an impingement/effusion cooling system. To simulate the rotating impingement/effusion system, a test duct with injection and effusion holes is installed on the rotating system. The jet Reynolds number based on the hole diameter is fixed to 3,000 and the Rotation number is set to 0.032. The experiments are carried out for various parameters such as the plate spacing to hole diameter ratio (H/d), orientation of the jet relative to the rotating axis and the tests for the array jet cooling are performed together. The naphthalene sublimation method is used to obtain the heat/mass transfer coefficients on the effusion plate. The local heat/mass transfer distributions are altered by the rotation. For the impingement/effusion cooling with orthogonal orientation, the low and non-uniform heat/mass transfer occurs between the effusion holes because the impinging jet is deflected by the Coriolis force. At a small H/d, the rotation enhances the heat/mass transfer in the stagnation region due to an increase in flow mixing. The impingement/effusion cooling with H/d = 2 shows the most efficient cooling performance and it is confirmed that the crossflow and H/d affect the averaged Sh value significantly under rotating conditions.

Fluid-mechanical effects on the combustion rate of solid carbon

1975 ◽  
Vol 25 ◽  
pp. 57-66 ◽  
Author(s):  
Kiyoshi Matsui ◽  
Akio Kôyama ◽  
Kimio Uehara
Keyword(s):  
Combustion Rate ◽  
Solid Carbon ◽  
Mechanical Effects

scholarly journals Surface Injection Effect on Mass Transfer From a Cylinder in Crossflow: A Simulation of Film Cooling in the Leading Edge Region of a Turbine Blade

1989 ◽  
Author(s):  
J. Karni ◽  
R. J. Goldstein
Keyword(s):  
Mass Transfer ◽  
Turbine Blade ◽  
Film Cooling ◽  
Leading Edge ◽  
Edge Region ◽  
Stagnation Region ◽  
Stagnation Line ◽  
Naphthalene Sublimation Technique ◽  
Circular Holes ◽  
Cooling Effects

A naphthalene sublimation technique is used to study the effect of surface injection on the mass (heat) transfer from a circular cylinder in crossflow. Using a heat/mass transfer analogy the results can be used to predict film cooling effects in the leading edge region of a turbine blade. Air injection through one row of circular holes is employed in the stagnation region of the cylinder. Streamwise and spanwise injection inclinations are studied separately, and the effects of blowing rate and injection location relative to the cylinder front stagnation line are investigated. Streamwise injection produces significant mass transfer increases downstream of the injection holes, but a relatively small increase is observed between holes, normal to the injection direction. The mass transfer distribution, measured with spanwise injection through holes located near the cylinder front stagnation line, is extremely sensitive to small changes in the injection hole location relative to stagnation. When the centers of the spanwise injection holes are located 5° or more from the stagnation line, the holes lay entirely on one side of the stagnation line and the injection affects the mass transfer only on that side of the cylinder, approaching the pattern observed with streamwise injection.

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