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Finite-Element Analysis of a Thick-Wall Tube Containing a Crater-Like Surface Flaw

Description: A three-dimensional finite-element elastic analysis is carried out for a thick-wall tube (as sued in typical LMFBR steam generators) that contains a surface flaw in the form of a paraboloid of revolution. Effects of the depth and aspect ratio of the flaw on the stress distribution and stress concentration in the tube are explored.
Date: June 1976
Creator: Majumdar, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Avoiding Leakage Flow-Induced Vibration by a Tube-in-Tube Slip Joint

Description: Parameters and operating conditions (a stability map) were determined for which a specific slip-joint design did not cause self-excited lateral vibration of the two cantilevered, telescoping tubes forming the joint. The joint design featured a localized annular constriction. Flowrate, modal damping, tube engagement length, and eccentric positioning were among the parameters tested. Interestingly, all self-excited vibrations could be avoided by following a simple design rule: place constrictions… more
Date: October 1984
Creator: Mulcahy, T. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Leakage Flow-Induced Vibrations for Variations of a Tube-in-Tube Slip Joint

Description: Variations in the design of a specific slip joint separating two cantilevered, telescoping tubes conveying water were studied to determine their effect upon the leakage flow-induced vibration self-excitation mechanism known to exist for the original slip joint geometry. The important parameters controlling the self-excitation mechanism were identified, which, along with previous results, allowed the determination of a comprehensive set of design rules to avoid unstable vibrations. This was poss… more
Date: January 1986
Creator: Mulcahy, T. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Instability Characteristics of Fluidelastic Instability of Tube Rows in Crossflow

Description: An experimental study is reported to investigate the jump phenomenon in critical flow velocities for tube rows with different pitch-to-diameter ratios and the excited and intrinsic instabilities for a tube row with a pitch-to-diameter ratio of 1.75. The experimental data provide additional insights into the instability phenomena of tube arrays in crossflow.
Date: April 1986
Creator: Chen, Shoei-Sheng & Jendrzejczyk, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Leakage Flow-Induced Vibration of an Unconstricted Tube-in-Tube Slip Joint

Description: The conditions are given for which the more flexible of two cantilevered, telescoping tubes conveying fluid can be self-excited by flow leaking from an un-constricted slip joint. Also, a physical explanation of the excitation mechanism is discussed, and a design rule to avoid the mechanism is presented. In addition, the results for the un-constricted slip joint are shown to be similar to those for slip joints having annulus constrictions at very short engagement lengths.
Date: March 1986
Creator: Mulcahy, T. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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General Theory for Dynamic Instability of the SSME LOX Posts

Description: A general theory of fluid-elastic instability for a tube array in crossflow is presented for application to the space shuttle main engine liquid oxygen (SSME LOX) posts. Various techniques to obtain the motion-dependent fluid-force coefficients are discussed and the general instability characteristics are summarized. The theory is also used to evaluate the results of other mathematical models for crossflow-induced instability.
Date: September 1985
Creator: Chen, Shoei-Sheng
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Fluid Excitation Forces Acting on a Tube Array

Description: Fluid forces are important in the assessment of vibration of the Space Shuttle Main Engine liquid oxygen posts. This report summarizes the available data on fluid excitation forces acting on tube arrays in turbulent crossflow, and test results for an array of tubes subject to turbulent flow. The fluctuating drag and lift forces are measured as a function of Reynolds number, incoming flow conditions, and tube location in an array.
Date: September 1985
Creator: Chen, Shoei-Sheng & Jendrzejczyk, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Stability of Tubes Conveying Fluid

Description: Tests and analysis are made for tubes conveying fluid for two types of support conditions. The objectives are to study the characteristics of different types of instability, the transition of one instability mechanism to another, and the control of instability.
Date: April 1984
Creator: Chen, Shoei-Sheng & Jendrzejczyk, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubes : Second Annual Report, October 1978-September 1979

Description: This report discusses the development of ultrasonic testing, acoustic microscopy, dye-enhanced radiography, holographic interferometry, and infrared scanning techniques for flaw detection in silicon carbide (SiC) heat-exchanger tubing. Both preservice and in-service testing requirements are discussed. An ultrasonic boreside probe and an acoustic microscope stage have been designed for continuous monitoring of SiC tubing. Preliminary results with these acoustic systems are presented. In addition… more
Date: November 1979
Creator: Kupperman, D. S.; Yuhas, D.; Deininger, W. & Sciammarella, Cesar A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Stability of Tube Rows in Crossflow

Description: A mathematical model for the instability of tube rows subjected to crossflow is examined. The theoretical model, based on the fluid-force data for a pitch-to-diameter ratio of 1.33, provides additional insight into the instability phenomenon. Tests are also conducted for three sets of tube rows. The effects of mass ratio, tube pitch, damping, detuning and finned tubes are investigated. Theoretical results and experimental data are in good agreement.
Date: October 1982
Creator: Chen, S. S. & Jendrzejczyk, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Fluidelastic Instability in Shell and Tube Heat Exchangers: A Framework for a Prediction Method

Description: A framework for a method to predict fluid-elastic instability in heat exchanger tube bundles is presented. The method relies on a three-dimensional, cylindrical coordinate, thermal-hydraulic analysis code to obtain a representation of the three-dimensional flow distribution within the heat exchanger. With this information, local cross-flow velocities corresponding to each tube in the exchanger are obtained by interpolation and resultant cross-flow velocity distributions are computed. With a kno… more
Date: December 1982
Creator: Wambsganss, M. W.; Yang, C. I. & Halle, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Shellside Waterflow Pressure Drop and Distribution in Industrial-Size Test Heat Exchanger

Description: The shellside pressure drop between the inlet and outlet nozzles as well as the pressure drops through individual sections of different shell-and-tube test-exchanger configurations are measured under water flow. The segmentally baffled test exchanger is nominally 0.6 m (2 ft) in diameter, 3.7 m (12 ft) long and contains a tube bundle of 19 mm (0.75 in.) outside-diameter tubes. Results are reported of 24 test cases obtained from various combinations of parameters: 30 degrees triangular or 90 deg… more
Date: January 1983
Creator: Halle, Henry & Wambsganss, M. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Tube Vibration in Industrial-Size Test Heat Exchanger (90° Square Layout)

Description: Tube vibrations in heat exchangers are being systematically investigated in a series of tests performed with an industrial-size test exchanger. Results from water-flow tests of eleven different tube bundles, in six- and eight-cross-pass configurations on a 90 degree square layout with a pitch-to-diameter ratio of 1.25 are reported. The test cases include full tube bundles, no-tubes-in-window bundles, finned tube bundles, and proposed field and design fixes. The testing focused on identification… more
Date: February 1983
Creator: Halle, Henry & Wambsganss, M. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experiments on Tubes Conveying Fluid

Description: Tests are conducted for tubes conveying fluid for six types of support conditions. The objectives are to understand the dynamic characteristics of such systems for different support conditions and to explore the methods to control tube stability. Transition from one instability mechanism to another is examined, and the feasibility of using feedback control to increase the critical flow velocity is demonstrated.
Date: February 1983
Creator: Jendrzejczyk, J. A. & Chen, S. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Design Guide for Calculating Fluid Damping for Circular Cylindrical Structures

Description: Fluid damping plays an important role for structures submerged in fluid, subjected to flow, or conveying fluid. This design guide presents a summary of calculational procedures and design data for fluid damping for circular cylinders vibrating in quiescent fluid, crossflow, and parallel flow.
Date: June 1983
Creator: Chen, S. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Leakage-Flow-Induced Vibration of a Tube-in-Tube Slip Joint

Description: The susceptibility of a cantilevered tube conveying water to self-excitation by leakage flow through a slip joint is assessed experimentally. The slip joint is formed by inserting a smaller, rigid tube into the free end of the cantilevered tube. Variations of the slip joint annular gaps and engagement lengths are tested, and several mechanisms for self-excitation are described.
Date: June 1983
Creator: Mulcahy, T. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Dynamics of Tubes in Fluid with Tube-Baffle Interaction

Description: Three series of tests are performed to evaluate the effects of tube to tube-support-plate (TSP) clearance on tube dynamic characteristics and instability phenomena for tube arrays in crossflow. Test results show that, for relatively large clearances, tubes may possess TSP-inactive modes in which the tubes rattle inside some of the tube-support-plate holes, and that the natural frequencies of TSP-inactive modes are lower than those of TSP-active modes, in which the support plates provide knife-e… more
Date: September 1983
Creator: Chen, S. S.; Jendrzejczyk, J. A. & Wambsganss, M. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chaotic Dynamics of Loosely Supported Tubes in Crossflow

Description: By means of the unsteady-flow theory and a bilinear mathematical model, a theoretical study was conducted of the chaotic dynamics associated with the fluid-elastic instability of loosely supported tubes. Calculations were performed for the RMS of tube displacement, bifurcation diagram, phase portrait, power spectral density, and Poincare map. Analytical results show the existence of chaotic, quasi-periodic, and periodic regions when flow velocity exceeds a threshold value.
Date: July 1991
Creator: Cai, Y. & Chen, Shoei-Sheng
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chaotic Vibrations of Nonlinearly Supported Tubes in Crossflow

Description: By means of the unsteady-flow theory and a bilinear mathematical model, a theoretical study is presented for chaotic vibrations associated with the fluid-elastic instability of nonlinearly supported tubes in a crossflow. Effective tools, including phase portraits, power spectral density, Poincare maps, Lyapunov exponent, fractal dimension, and bifurcation diagrams, are utilized to distinguish periodic and chaotic motions when the tubes vibrate in the instability region. The results show periodi… more
Date: February 1992
Creator: Cai, Y. & Chen, Shoei-Sheng
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Motion-Dependent Fluid Forces Acting on Tube Arrays in Crossflow

Description: Motion-dependent fluids forces acting on a tube array were measured as a function of excitation frequency, excitation amplitude, and flow velocity. Fluid-damping and fluid-stiffness coefficients were obtained from measured motion-dependent fluid forces as a function of reduced flow velocity and excitation amplitude. The water channel and test setup provide a sound facility for obtaining key coefficients for fluid-elastic instability of tube arrays in crossflow. Once the guideline, based on the … more
Date: June 1993
Creator: Chen, Shoei-Sheng; Zhu, S. & Jendrzejczyk, J. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Experiment on Fluidelastic Instability of Loosely Supported Tube Arrays in Crossflow

Description: A tube array supported by baffle plates in crossflow may be subjected to fluid-elastic instability in the tube-support-plate-inactive mode. An experimental study is presented to characterize the tube motion. Three series of tests were performed to measure tube displacements as a function of flow velocity for different clearances. The motion was examined by root-mean-square values of tube displacements, power spectral densities, phase planes, Poincare maps, and Lyapunov exponents. The experiment… more
Date: June 1993
Creator: Chen, Shoei-Sheng; Zhu, S. & Cai, Y.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nondestructive Evaluation Techniques for Silicon Carbide Heat-Exchanger Tubes : Annual Report, October 1977-September 1978

Description: This report discusses the adequacy of several nondestructive evaluation techniques for the detection of flaws in silicon carbide heat-exchanger tubing. Experimental results have been obtained for conventional ultrasonic testing, acoustic microscopy, conventional and dye-enhanced radiography, holographic interferometry, infrared scanning and internal-friction measurements.
Date: March 1979
Creator: Kupperman, D. S.; Yuhas, D.; Sciammarella, Cesar A.; Lapinski, N. P. & Fiore, N. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Motion-Dependent Fluid Forces Acting on a Tube Row in Crossflow

Description: Motion-dependent fluid forces acting on a tube row with a pitch-to-diameter ratio of 1.35 are measured for several flow velocities and a series of oscillation frequencies. Fluid-damping and fluid-stiffness coefficients are obtained from motion-dependent fluid forces as a function of reduced flow velocity. Fluid-force coefficients agree reasonably with published data. Based on the fluid-force coefficients, the critical flow velocity and instability characteristics of tube arrays in crossflow can… more
Date: October 1986
Creator: Jendrzejczyk, J. A. & Chen, Shoei-Sheng
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Prediction of Tube Bundle Instabilities : Case Studies

Description: The concurrent acquisition of flow-induced vibration (FIV) test data for several configurations of an industrial-size shell-and-tube heat exchanger made possible this evaluation of the HXVA method for six cases. Recommendations to improve the prediction capability were made, with priority on the excitation mechanism for dense fluid flows with non-uniform velocity distributions.
Date: November 1986
Creator: Mulcahy, T. M.; Halle, Henry & Wambsganss, M. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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