Effects of local mechanical collision with shear stress on the phase transformation fromα-quartz to coesite induced by high static pressure

2006 ◽  
Vol 73 (14) ◽  
Author(s):  
Wen-Hui Su ◽  
Shu-E Liu ◽  
Da-Peng Xu ◽  
Wei-Ran Wang ◽  
Bin Yao ◽  
...  
Keyword(s):  
Shear Stress ◽  
Phase Transformation ◽  
Static Pressure ◽  
High Static Pressure

Phase transformation of iron under shock compression: Effects of voids and shear stress

2008 ◽  
Vol 78 (2) ◽  
Author(s):  
Xinlin Cui ◽  
Wenjun Zhu ◽  
Hongliang He ◽  
Xiaoliang Deng ◽  
Yingjun Li
Keyword(s):  
Shear Stress ◽  
Phase Transformation ◽  
Shock Compression ◽  
Compression Effects

Preston-Static Tubes for the Measurement of Wall Shear Stress

1994 ◽  
Vol 116 (3) ◽  
pp. 645-649 ◽  
Author(s):  
Josef Daniel Ackerman ◽  
Louis Wong ◽  
C. Ross Ethier ◽  
D. Grant Allen ◽  
Jan K. Spelt
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Convenient Method ◽  
Pipe Flow ◽  
Total Pressure ◽  
Static Pressure ◽  
Shear Stresses ◽  
Streamline Curvature ◽  
Syringe Needle ◽  
Wall Shear

We present a Preston tube device that combines both total and static pressure readings for the measurement of wall shear stress. As such, the device facilitates the measurement of wall shear stress under conditions where there is streamline curvature and/or over surfaces on which it is difficult to either manufacture an array of static-pressure taps or to position a single tap. Our “Preston-static” device is easily and conveniently constructed from commercially available regular and side-bored syringe needles. The pressure difference between the total pressure measured in the regular syringe needle and the static pressure measured in the side-bored one is used to determine the wall shear stress. Wall shear stresses measured in pipe flow were consistent with independently determined values and values obtained using a conventional Preston tube. These results indicate that Preston-static tubes provide a reliable and convenient method of measuring wall shear stress.

scholarly journals Performance Assessment of an Annular S-Shaped Duct

1995 ◽  
Author(s):  
D. W. Bailey ◽  
K. M. Britchford ◽  
J. F. Carrotte ◽  
S. J. Stevens
Keyword(s):  
Shear Stress ◽  
Static Pressure ◽  
Compressor Blade ◽  
Turbine Engines ◽  
Pressure Gradients ◽  
Gas Turbine Engines ◽  
Entry Length ◽  
Static Pressure Distribution ◽  
Flow Curvature ◽  
Inlet Conditions

An experimental investigation has been carried out to determine the aerodynamic performance of an annular S-shaped duct representative of that used to connect the compressor spools of aircraft gas turbine engines. For inlet conditions in which boundary layers are developed along an upstream entry length the static pressure, shear stress and velocity distributions are presented. The data shows that as a result of flow curvature significant streamwise pressure gradients exist within the duct, with this curvature also affecting the generation and suppression of turbulence. The stagnation pressure loss within the duct is also assessed and is consistent with the measured distributions of shear stress. More engine representative conditions are provided by locating a single stage compressor at inlet to the duct. Relative to the naturally developed inlet conditions the flow within the duct is less likely to separate, but mixing out of the compressor blade wakes increases the measured duct loss. With both types of inlet conditions the effect of a radial strut, such as that used for carrying loads and engine services, is also described both in terms of the static pressure distribution along the strut and its contribution to overall loss.

An Experimental Study of Local Wall Shear Stress, Surface Static Pressure, and Flow Visualization Upstream, Alongside, and Downstream of a Blade Endwall Corner

1991 ◽  
Vol 113 (4) ◽  
pp. 626-632 ◽  
Author(s):  
A. K. Abdulla ◽  
R. K. Bhargava ◽  
R. Raj
Keyword(s):  
Experimental Study ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Flow Visualization ◽  
Static Pressure ◽  
Leading Edge ◽  
Chord Length ◽  
Corner Region ◽  
Wall Shear ◽  
Blade Leading Edge

The experimental study reported in this paper was performed to acquire information on the distribution of wall shear stress and surface static pressure in a blade endwall corner. The blade endwall corner region investigated was divided into three sections: 0.4 chord length upstream of the blade leading edge, inside the endwall corner region, and one chord length downstream of the blade trailing edge. The maximum increases in the values of wall shear stress were found to exist on the endwall, in the corner region, between the blade leading edge and the location of maximum blade thickness (≈ 140 percent maximum increase, compared to its far upstream value, at x/D = 6). Surface flow visualization defined the boundaries of the vortex system and provided information on the direction and magnitude of the wall shear stress. The acquired results indicated that the observed variations of wall shear stress and surface static pressure were significantly influenced by the interaction of secondary flows with pressure gradients induced by the presence of blade curvature.

Performance Assessment of an Annular S-Shaped Duct

1997 ◽  
Vol 119 (1) ◽  
pp. 149-156 ◽  
Author(s):  
D. W. Bailey ◽  
K. M. Britchford ◽  
J. F. Carrote ◽  
S. J. Stevens
Keyword(s):  
Shear Stress ◽  
Static Pressure ◽  
Compressor Blade ◽  
Turbine Engines ◽  
Pressure Gradients ◽  
Gas Turbine Engines ◽  
Entry Length ◽  
Static Pressure Distribution ◽  
Flow Curvature ◽  
Inlet Conditions

An experimental investigation has been carried out to determine the aerodynamic performance of an annular S-Shaped duct representative of that used to connect the compressor spools of aircraft gas turbine engines. For inlet conditions in which boundary layers are developed along an upstream entry length, the static pressure, shear stress and velocity distributions are presented. The data show that as a result of flow curvature, significant streamwise pressure gradients exist within the duct, with this curvature also affecting the generation and suppression of turbulence. The stagnation pressure loss within the duct is also assessed and is consistent with the measured distributions of shear stress. More engine representative conditions are provided by locating a single-stage compressor at inlet to the duct. Relative to the naturally developed inlet conditions, the flow within the duct is less likely to separate, but mixing out of the compressor blade wakes increases the measured duct loss. With both types of inlet conditions, the effect of a radial strut, such as that used for carrying loads and engine services, is also described both in terms of the static pressure distribution along the strut and its contribution to overall loss.

A Note on the Static Hole Error Problem

1966 ◽  
Vol 70 (662) ◽  
pp. 370-370 ◽  
Author(s):  
N. Rajaratnam
Keyword(s):  
Shear Stress ◽  
Dynamic Viscosity ◽  
Static Pressure ◽  
Mass Density ◽  
Hole Diameter ◽  
The Past ◽  
Boundary Shear ◽  
The Difference ◽  
Boundary Shear Stress

The static hole error problem has been extensively investigated in the past. It has been shown that, for deep holes (for which the length l of the hole is greater than 1.5 times the diameter d of the hole), the difference between the indicated static pressure p0’ and the true static pressure p0 is a function of the boundary shear stress τ0, hole diameter d, the coefficient of dynamic viscosity μ and the mass density ρ of the fluid.

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