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Experimental investigations of the film cooling effectiveness of a Micro-Tangential-Jet Scheme on a Gas Turbine Vane

Research Abstract
This paper presents experimental investigations of the film cooling effectiveness of a Micro-Tangential- Jet (MTJ) Film cooling scheme on a gas turbine vane using transient Thermochromic Liquid Crystal (TLC) technique. The MTJ scheme is a micro-shaped scheme designed so that the secondary jet is supplied tangentially to the vane surface. The scheme combines the benefits of micro jets and tangential injection. The film cooling performance of one row of holes on both pressure and suction sides were investigated at a blowing ratio ranging from 0.5 to 1.5 on the pressure side and 0.25 to 0.625 on the suction side. The average density ratio during the investigations was 0.93, and the Reynolds Number was 1.4E+5, based on the free stream velocity and the main duct hydraulic diameter. The pitch to diameter ratio of the cooling holes is 5 on the pressure side and 6.5 on the suction side. The turbulence intensity during all investigations was 8.5%. Minor changes in the Mach number distribution around the airfoil surface were observed due to the presence of the MTJ scheme, compared with the case with no MTJ scheme. The investigations showed great film cooling performance for the MTJ scheme, high effectiveness values and excellent lateral jet spreading. The performance of tangential injection over actual airfoil surfaces was found close, qualitatively, to that observed over flat plate. A 2-D coolant film was observed in the results, which is a characteristic of the continuous slot schemes only. The presence of this 2-D film layer helps minimize the rate of mixing between the main and the secondary streams. This film help establish uniform thermal loads on the surface. Furthermore, it was noticed that the rate of effectiveness decay on the suction side was lower than that of the pressure side while the lateral jet spreading on the pressure side was better than on suction side. The main disadvantage of the MTJ scheme is the increased pressure drop across the scheme, compared to traditional shaped schemes.
Research Authors
O. Hassan and I. Hassan
Research Journal
Int. J. of Heat and Mass Transfer
Research Pages
158-171
Research Rank
1
Research Vol
61
Research Year
2013

Experimental Investigations of the Film Cooling Performance of a Micro-Tangential-Jet Scheme on a Gas Turbine Vane: Part 2—Heat Transfer Coefficient

Research Authors
O Hassan, I Hassan
Research Journal
ASME 2012 International Mechanical Engineering Congress and Exposition
Research Publisher
American Society of Mechanical Engineers
Research Rank
3
Research Year
2012

Experimental Investigations of the Film Cooling Performance of a Micro-Tangential-Jet Scheme on a Gas Turbine Vane: Part 1—Effectiveness

Research Authors
O Hassan, I Hassan
Research Journal
ASME 2012 International Mechanical Engineering Congress and Exposition
Research Publisher
American Society of Mechanical Engineers
Research Rank
3
Research Year
2012

Droplet-Scale Estrogen Assays in Breast Tissue, Blood, and Serum

Research Abstract
Estrogen is a key hormone in human reproductive physiology, controlling ovulation and secondary sexual characteristics. In addition, it plays an important role in the pathogenesis of breast cancer. Indeed, estrogen receptor antagonists and aromatase inhibitors (which block estrogen biosynthesis) are primary drugs used for treatment and prevention in at-risk populations. Despite its importance, tissue concentrations of estrogen are not routinely measured because conventional techniques require large samples of biopsies for analysis. In response to this need, we have developed a digital microfluidic method and applied it to the extraction and quantification of estrogen in 1 microliter samples of breast tissue homogenate (as would be collected with fine-needle aspiration), as well as in whole blood and serum. This method may be broadly applicable to conditions requiring frequent analysis of hormones in clinical samples (for example, infertility and cancer).
Research Authors
N. A. Mousa, M. J. Jebrail, H. Yang, M. Abdelgawad, P. Metalnikov, J. Chen, A. R. Wheeler, and R. F. Casper
Research Journal
Science Translational Medicine
Research Pages
1ra2
Research Publisher
American Association for the Advancement of Science (AAAS)
Research Rank
1
Research Vol
vol. 1, n. 1
Research Website
http://stm.sciencemag.org/content/1/1/1ra2
Research Year
2009
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