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RESEARCH PAPERS

J. Basic Eng. 1963;85(1):1-12. doi:10.1115/1.3656517.

This paper presents experimental measurements on cavitation performance effects for a venturi test section and a centrifugal pump. Theoretical expectations and comparisons with previous investigators’ data are discussed. The following general conclusions are drawn. (1) Significant scale effects were found for all degrees of cavitation, and for both venturi and pump. The direction of the effects is consistent with present literature. (2) Certain of these effects can be correlated in terms of Reynolds’ number; however, Reynolds’ number alone is not a sufficient correlating parameter.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):17-28. doi:10.1115/1.3656516.

Three mixed flow impellers representing a wide range of design parameters were tested in a closed water loop to obtain correlations of the high-speed photographic records of the cavitation formations with various performance parameters. It was found that cavitation existed for all impellers at much higher values of NPSH than those associated with a finite drop in the impeller head rise. The cavitation formations in the vane channels of the impellers were observed to be cyclic in nature, whereas the cavitation near the leading edge of the vanes was more stable.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):29-33. doi:10.1115/1.3656521.

This paper reports measurements of mean velocities, turbulence intensities, and turbulence (Reynolds) stresses in the inlet region of a smooth pipe. Data are presented for the first 40 diameters of pipe length. Fully developed flow is not attained in this length for a Reynolds number (based on pipe diameter and mean velocity) of 388,000, but the wall shear stress and the static pressure gradient attain their fully developed values within the first 15 diameters. Velocity profiles at successive sections in the inlet region are not similar as assumed in some published calculation methods. Longitudinal convection of turbulence energy is appreciable; except very near the pipe entrance, radial convection is negligible.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):35-38. doi:10.1115/1.3656525.

Measurements of velocity, turbulence intensity, and Reynolds stress distributions following a sudden increase in surface roughness of a pipe are reported. The wall shear stress increases abruptly to its final value and the pressure gradient is very nearly constant throughout the transition region. Reynolds stresses throughout much of the transition region reach values exceeding those in fully developed flow in the rough pipe. The need for knowledge of shear stress distributions for use in the calculation of velocity distributions is pointed out. A flow model is suggested.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):41-45. doi:10.1115/1.3656529.

The original development by Schiller for flow in the entrance of a tube is corrected to account for viscous dissipation within the boundary layer. The result is the best over-all description of velocity within the tube entrance currently available.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):47-53. doi:10.1115/1.3656534.

An investigation of the jet development, the velocity profiles, and the wall shearing stress in a two-dimensional, incompressible, turbulent wall jet was undertaken. The maximum velocity decay, jet thickness, and the shearing stress are predicted analytically by momentum-integral methods. Experimental data concerning velocity profiles, velocity decay, and jet thickness agree well with previous investigators. The wall shearing stress was measured by a hot-film technique and the results help to resolve a wide divergence between the experimental values of other investigators.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):55-62. doi:10.1115/1.3656537.

An analytical and experimental study is made of the development of secondary vorticities through the successive blade rows of a turbomachine. Whereas in cascade experiments the streamwise vorticity is usually zero at entry to the cascade, in the turbomachine this vorticity is in general nonzero and must be taken into account in the calculation of the secondary vorticity at exit from a blade row. In the calculation of boundary layer velocity profiles through an axial flow compressor stage, the variations in the exit air angles from the rows are computed first, from estimates of the secondary vorticities. There will always be overturning at the exit from the guide vane tip section, but tracing of the vorticity vectors through the machine shows that there may be underturning at rotor and stator tip. The exit air angles obtained from the analysis of these secondary flows may be used, together with actuator disk theory, to calculate axial velocity profiles in the boundary layers. It is suggested that this method of calculating the flow in the regions near the annulus walls should be used in the design of axial flow compressors.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):66-70. doi:10.1115/1.3656542.
Abstract
Topics: Creep , Rotating Disks
Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):71-86. doi:10.1115/1.3656543.

The creep-rupture behavior of 34 capped end, thin-wall tubular specimens was correlated with results for 54 uniaxial tensile specimens in tests at 1350 F, 1500 F, and 1650 F. Basic tests established isotropy in creep-rupture properties as well as metallurgical stability for the material used in the study. Significant correlations of creep rate, rupture life, and rupture ductility were established for the cases of stress ratios 1/0 and 2/1 in the biaxial tension quadrant. Data from tests at 1500 F were evaluated for a statistical argument. This same material was subsequently utilized in a high temperature structures research program to be reported separately.

Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):97-101. doi:10.1115/1.3656547.

The effect of warm prestressing at various stress levels on the notch bend fracture properties of a Ni-Mo-V steel at two levels of strength and Charpy FATT is determined. Warm prestressing of a notch sensitive steel effected increases in notch fracture strengths up to 150 percent of the unprestressed value. The fracture strength after prestressing increases proportionately with prestress level. The results indicate that the efficacy of warm prestressing is dependent on the temperature at which the notch strength is determined and its relation to the notch strength versus temperature behavior for a material.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):105-112. doi:10.1115/1.3656496.

Plastic deformation that accumulates with running time may constitute a mode of failure in some rolling element applications, particularly at elevated temperature. This phenomenon is studied in a simple room temperature investigation involving annealed brass toroids and cylinders mated with hard steel rollers. Evidence of sizable accumulation of plastic strain with cycles of rolling, despite subsequent contact stress reduction, leads to a consideration of the effect of a complex combined stress history, such as that induced by the rolling action, on plastic flow in metals.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):116-120. doi:10.1115/1.3656501.

Using the saturation of hysteresis energy absorption as a criterion for fatigue crack propagation, the rate of crack propagation in a thin and wide metal sheet under repeated axial loading is found to be proportional to the square of the applied stress range. The local stress and strain fields adjacent to the crack tip are employed to compute the energy density. The analytical results correlate very well with the experimental results on 2024-T3 aluminum alloy.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):123-128. doi:10.1115/1.3656505.

An analysis is made of the performance of narrow porous metal bearings (e.g., sintered bronze powder) which operate with a full film of lubricant. The configuration considered is that in which the bearings are pressed tightly into housings with their ends remaining open to the atmosphere. A solution for the lubricant pressure is obtained which satisfies Reynolds’ equation in the film and Laplace’s equation in the porous metal. Expressions are developed which give the Sommerfeld and Ocvirk numbers, attitude angle, and coefficient of friction as functions of eccentricity ratio, permeability parameter, and thickness-to-length ratio. The results are shown graphically for situations of practical importance.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1963;85(1):129-135. doi:10.1115/1.3656508.

A theoretical analysis is made of the finite step slider bearing using an electrically conducting liquid metal lubricant in the presence of a magnetic field applied both tangentially and transversely to the fluid film. The electrical terminal characteristics are discussed. For the transverse field it is found that only a slight increase in pressurization can be effected on open circuit conditions and that the short circuit condition is adverse. For the tangential field the effect is adverse for both open and short circuit. By supplying electrical power from an external source, however, significant increases in load carrying capacity can be achieved for both field geometries. Various curves of normalized load versus Hartmann number and pressure contour plots are presented.

Commentary by Dr. Valentin Fuster

DISCUSSIONS

Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster

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