Reference temperature method for computing displacement thickness

AIAA Journal ◽  
1964 ◽  
Vol 2 (11) ◽  
pp. 2056-2057 ◽  
Author(s):  
M. SAARLAS
Keyword(s):  
Reference Temperature ◽  
Temperature Method ◽  
Displacement Thickness

A Reference Temperature Method for Compressible Laminar Boundary Layers

1973 ◽  
Vol 2 (4) ◽  
pp. 201-204
Author(s):  
R. Camarero
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Reference Temperature ◽  
Integral Approach ◽  
Pressure Gradients ◽  
Two Dimensional ◽  
Laminar Boundary Layers ◽  
Temperature Method ◽  
Compressibility Effects

A calculation procedure for the solution of two-dimensional and axi-symmetric laminar boundary layers in compressible flow has been developed. The method is an extension of the integral approach of Tani to include compressibility effects by means of a reference temperature. Arbitrary pressure gradients and wall temperature can be specified. Comparisons with experiments obtained for supersonic flows over a flat plate indicate that the method yields adequate results. The method is then applied to the solution of the boundary layer on a Basemann inlet.

Reference Temperatures for Supercritical Laminar Free Convection on a Vertical Flat Plate

1981 ◽  
Vol 103 (4) ◽  
pp. 613-616 ◽  
Author(s):  
A. J. Ghajar ◽  
J. D. Parker
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Free Convection ◽  
Flat Plate ◽  
Reference Temperature ◽  
Variable Property ◽  
Temperature Method ◽  
Theoretical Results ◽  
Vertical Flat Plate ◽  
Good Agreement

A reference temperature method was developed by which heat transfer to fluids in the supercritical region under variable property conditions in laminar free convection on a vertical flat plate can be readily evaluated. Based on this method three generalized plots for Refrigerant-114, water, and carbon dioxide were developed. The results obtained with the reference temperature scheme showed good agreement with the existing experimental data and theoretical results for these three variable property fluids.

Theory and application of two-dimension viscous hydraulic design of the ultra-low specific-speed centrifugal pump

2019 ◽  
Vol 234 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Cong Wang ◽  
Yongxue Zhang ◽  
Hucan Hou ◽  
Zhiyi Yuan
Keyword(s):  
Boundary Layer ◽  
Centrifugal Pump ◽  
Diagnostic Model ◽  
Two Dimension ◽  
Cavitation Performance ◽  
Hydraulic Design ◽  
Displacement Thickness ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Low Efficiency

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.

"New Donors" in Czochralski Grown Silicon Annealed at T≥ 600°C under Compressive Stress

2005 ◽  
Vol 108-109 ◽  
pp. 181-186 ◽  
Author(s):  
Valentin V. Emtsev ◽  
Boris A. Andreev ◽  
Gagik A. Oganesyan ◽  
D.I. Kryzhkov ◽  
Andrzej Misiuk ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Compressive Stress ◽  
Reference Temperature ◽  
Enhancement Effect ◽  
Shallow Acceptor ◽  
Thermal Donor ◽  
Compressive Stresses ◽  
Heat Treated ◽  
Donor Formation ◽  
New Donors

Effects of compressive stress on oxygen agglomeration processes in Czochralski grown silicon heat treated at T= 450OC, used as a reference temperature, and T= 600OC to 800OC are investigated in some detail. Compressive stresses of about P= 1 GPa lead to enhanced formation of Thermal Double Donors in materials annealed over a temperature range of T= 450OC – 600OC. It has been shown that the formation of thermal donors at T= 450OC under normal conditions and compressive stress is accompanied with loss of substitutional boron. In contrast, the concentration of the shallow acceptor states of substitutional boron in silicon annealed under stress at T≥ 600OC remains constant. An enhancement effect of thermal donor formation is gradually weakened at T≥ 700OC. The oxygen diffusivity sensitive to mechanical stress is believed to be responsible for the observed effects in heat-treated silicon.

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