Measurement of Pressure Loss and Flow Visualization in the Flow of Viscoelastic Fluids through Cylinder Arrays

Flow visualization, manometry, and laser-Doppler anemometry have been applied to approximately two-dimensional water flow around segmental baffles with baffle spacing/depth equal to 0.4, window cuts from 10 to 50 percent, and Reynolds numbers ranging from 600–10,500 in order to simulate important aspects relating to shellside flow in shell-and-tube heat exchangers. The main features of the flow (which is eventually periodic in the streamwise direction), development lengths, pressure loss coefficients, and mean and rms velocity distributions are presented.

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Flow visualization scaleup studies for the mixing of viscoelastic fluids

Chemical Engineering Science ◽

10.1016/0009-2509(91)85155-q ◽

1991 ◽

Vol 46 (11) ◽

pp. 2867-2873 ◽

Cited By ~ 16

Author(s):

Carl R. Shervin ◽

Dean A. Raughley ◽

Raymond A. Romaszewski

Keyword(s):

Flow Visualization ◽

Viscoelastic Fluids

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Analysis of Equivalent Pipe Flow System for K-10-8G Combustor

Volume 4 ◽

10.1115/ht-fed2004-56691 ◽

2004 ◽

Author(s):

Sivasankar Ganesan ◽

Vijay Subramanian

Keyword(s):

Flow Visualization ◽

Pipe Flow ◽

Pressure Loss ◽

Flow System ◽

Initial Flow ◽

The Core ◽

Branching Points ◽

Hardy Cross ◽

Flow Circuit ◽

Good Agreement

The pressure loss in the K-10-8G combustor has been quantified by constructing an equivalent pipe flow circuit where, the obstructions and branching are analogous to the flow pattern in the combustor. The adoption of skin friction coefficients and Hardy-Cross method cannot be employed due to the combustor’s short length (550 mm). For the evaluation of pressure loss, three flow systems have been constructed. In the first two systems, the fluid volume flowing through the core divides equally at the corresponding branching points, mixes with the flow from the outer annulus and combines back again. The third system is similar to the first except that the volumes combining after mixing are equal. The initial flow distributions in the core, outer and inner annuli were obtained from flow visualization. These systems can be used for corroborating the pressure loss produced, around 4.12%, which is in good agreement to that found from flow visualization (4.14%). The equivalent system was found to be similar to the combustor.

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Design, Performance Evaluation and Endwall Flow Structure Investigation of an S-Shaped Intermediate Turbine Duct

Volume 6: Turbo Expo 2007, Parts A and B ◽

10.1115/gt2007-27650 ◽

2007 ◽

Cited By ~ 10

Author(s):

Lars-Uno Axelsson ◽

Carlos Arroyo Osso ◽

David Cadrecha ◽

T. Gunnar Johansson

Keyword(s):

Performance Evaluation ◽

Flow Visualization ◽

Pressure Loss ◽

Loss Coefficient ◽

Flow Angle ◽

Guide Vanes ◽

Design Point ◽

Intermediate Turbine Duct ◽

Pressure Loss Coefficient ◽

And Performance

Annular S-shaped intermediate turbine ducts are used in modern multi-spool jet engines to connect the high pressure turbine with the low-pressure turbine. The trend towards engines with larger by-pass ratios requires the future intermediate turbine ducts to be shorter and have larger radial off-set. This paper deals with the design and performance evaluation of a state-of-the-art annular S-shaped intermediate turbine duct. The details of the design of the intermediate turbine duct are presented together with static pressure measurements and oil film flow visualization along the endwalls, and area traverses at the inlet and outlet planes using a 5-hole probe. The measurements were done for three operating points of the turbine. From the flow visualization no separation could be detected at design point conditions, but for off-design conditions regions of separation were detected on the guide vanes located within the inter-turbine duct. The pressure loss coefficient was shown to be comparable for the two cases with lowest swirl angle, but the design point showed a slightly lower pressure loss. For the case with the largest flow angle the pressure loss coefficient was clearly larger than for the other two cases, which can be associated with the separation found on the guide vanes.

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Endwall Losses and Flow Unsteadiness in a Turbine Blade Cascade

Journal of Turbomachinery ◽

10.1115/1.2927984 ◽

1992 ◽

Vol 114 (1) ◽

pp. 191-197 ◽

Cited By ~ 1

Author(s):

L. Adjlout ◽

S. L. Dixon

Keyword(s):

Boundary Layer ◽

Flow Visualization ◽

Turbine Blade ◽

Turbulence Intensity ◽

Pressure Loss ◽

Total Pressure ◽

Free Stream ◽

Total Pressure Loss ◽

Pressure Distributions ◽

Blade Cascade

The purpose of this paper is to describe an investigation of the flow within and downstream of a turbine blade cascade of high aspect ratio. A detailed experimental investigation into the changes in the endwall boundary layer in the cascade (100 deg camber angle) and total pressure loss downstream of the cascade was carried out. Flow visualization was used in order to obtain detailed photographs of the flow patterns on the endwall and for exhibiting the trailing edge vortices. Pressure measurements were carried out using a miniature cranked Kiel probe for three planes downstream of the cascade, with two levels of turbulence intensity of the free stream. Pressure distributions on the blade were measured at three spanwise locations, namely 4, 12, and 50 percent of the full span from the wall. Hot-wire anenometry combined with a spectrum analyzer program was used to determine the frequencies of the flow oscillations. The change in turbulence level of the free stream has a significant influence on all three pressure distributions. The striking difference between two of the pressure distributions is in the aft half of the suction side where the distribution with the lower turbulence intensity has the larger lift. The oil flow visualization reveals what appear to be two separation lines within the passage and are believed to originate from the horseshoe vortex. The pitchwise-averaged total pressure loss coefficient increases with the distance of the measurement plane downstream of the cascade blades. A substantial part of this loss increase close to the wall is caused by the high rate of shear of the new boundary layer on the endwall.

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Jet Curtain Flameholder for Aircraft Afterburners

Volume 1A: General ◽

10.1115/78-gt-95 ◽

1978 ◽

Author(s):

K. Sridhara ◽

M. S. Chidananda ◽

P. A. Paranjpe

Keyword(s):

Flow Visualization ◽

Pressure Loss ◽

Pressure Ratio ◽

Recirculation Zones ◽

Stability Limits ◽

Cold Pressure ◽

Jet Curtain

The similarity of flow behind V-gutter flameholders and the proposed jet curtain flameholders has been demonstrated from flow visualization studies. The effective blockage of jet curtain flameholders can be varied by varying the jet pressure ratio. The jet curtain flameholder gives the same stability limits as the V-gutter if the mixture strength in the recirculation zones is identical, while it has negligible cold pressure loss. Thus, the use of the jet curtain flameholder offers the possibility of significant reduction in overall weight of an aircraft for a given range, if the afterburning duration is short.

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