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RESEARCH PAPERS

J. Basic Eng. 1960;82(3):505-511. doi:10.1115/1.3662640.

This paper presents theoretical and experimental analysis of two types of circular hydrostatic thrust bearings, using incompressible lubricants. Design equations for load-carrying capacity, stiffness, and flow, are given for three different types of flow restriction—orifice, capillary, and constant flow. Experimental verification of the equations is shown. It is seen that each method of restriction imparts its own characteristics on the bearing performance. Constant flow, for instance, results in the stiffest bearing under certain conditions, and capillary restriction is unaffected by temperature changes.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):513-524. doi:10.1115/1.3662643.

It has been demonstrated that it is possible to measure the resistance of clothing as an ohmic relation between time-averaged equilibrium values of the flux of power (metabolism) and the potential difference between average skin temperature and ambient temperature. Specifically, this has been demonstrated on the human in what has been referred to as the comfort mode of operation of the human system. In this mode of operation, the metabolic level of activity is changed by signaling command to attempt to maintain a specific control level of the average skin temperature. With control attempted to approximately 0.1 deg C, sufficient precision has been achieved to resolve 1 or 2 per cent difference in clothes resistance. The dynamic input-output data obtained during clothes measurements are presented.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):528-536. doi:10.1115/1.3662647.

Experimental results are presented for the radial distributions of pressure and peripheral velocity for the turbulent flow of water in two closed curved channels of rectangular cross section and large depth-to-width ratio. The traverses were taken at the equatorial section of the channel and sufficiently far around the curve for the effect of curvature on the mean motion to be fully established. The two channels employed had widely differing mean-radius-to-width ratios n. The data obtained for a wide range of flow rates in the channel with a larger n indicated that Reynolds similarity existed between the flows in this channel. These data are compared with the pressure and velocity profiles predicted by potential flow theory and with a semiempirical logarithmic velocity distribution. Results obtained for the channel with smaller n showed that at above a certain Reynolds number an anomaly occurred in the flow, manifesting itself as an unstable “belt” of faster moving fluid, which moved outward from the inner wall as the Reynolds number was increased. This effect, considered to be the consequence of upstream stall, was accompanied by an adverse longitudinal-pressure gradient at the inner wall of the channel. It appeared to be eliminated by the insertion of an upstream splitter vane.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):539-549. doi:10.1115/1.3662650.

The flow of air in the space between a rotating disk and a stationary side wall placed parallel to its surface has been investigated over a range of Reynolds numbers from 3 × 105 to 6 × 106 at clearance-to-diameter ratios from 0.0125 to 0.0625. When the size of the stationary side wall was larger than the diameter of the rotating disk the flow in the gap was found to be periodic; several distinct and separate inflow and outflow regions were observed to rotate in the same direction as the disk, but at a slower speed. The number of flow regions was found to be a function of the disk speed and the gap size. The frictional torque on the housing was also measured and the effect of source flow on the flow pattern was studied qualitatively.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):553-560. doi:10.1115/1.3662656.

The effects of surface roughness on the frictional resistance of enclosed rotating disks have been studied experimentally. Torque data were obtained over the range of disk Reynolds numbers 4 × 103 to 6 × 106 for three different relative roughnesses a/k of 1000, 2000, and 3200 at three axial-clearance-to-disk-radius ratios s/a of 0.0227, 0.0609, and 0.112 for a constant, small, radial tip clearance. The existence of four possible basic flow regimes in the axial gap between the disk and casing wall was verified. Empirical expressions have been presented which predict the initial point of onset of turbulence in the flow within the boundary layer on the disk, the point at which the surface roughness becomes fully effective, and the magnitudes of the resistance coefficients in the zone of fully rough turbulent flow. The similarities and differences between smooth and rough-disk torque behavior, and to a limited extent boundary-layer behavior, have been noted.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):563-570. doi:10.1115/1.3662659.

Experimental investigations have shown that the flow discharged from a centrifugal compressor or pump impeller into a diffuser is often unsteady and axially asymmetric. A theory based upon a simplified model is developed for this type of flow. The theory predicts a significant reversible work transfer between parts of the flow with different velocities. This effect only occurs in cases of rotating distortion patterns; stationary distortion patterns, therefore, behave differently. Theoretical results are compared to measurements and good agreement is found. The implications of the theory have been investigated by means of machine computations and are discussed herein.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):575-584. doi:10.1115/1.3662666.

An analysis is presented for the variation of low-speed, minimum-loss, incidence angle and deviation angle for compressor-cascade blades. The aerodynamics governing the behavior of these angles is discussed, and the principal influencing parameters are established. A single general relation is obtained for predicting these angles for conventional sections such as the British C-series blades, the double circular-arc blade, and the NACA 65-series blades when the latter blade sections are expressed in terms of an equivalent circular-arc chamber line. The specific constants associated with each blade shape are derived from the available data.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):588-592. doi:10.1115/1.3662671.

This paper presents the results of a number of investigations concerned with the boundary-layer characteristics of turbomachine blade rows and their relation to the over-all blade loss. It is demonstrated how the over-all blade loss can be obtained from the momentum boundary-layer thickness. The momentum boundary-layer thickness is in turn shown to be correlated by flow Reynolds number and total blade surface diffusion. By assuming Zweifel’s form of blade-loading diagram the total blade surface diffusion parameter can be determined as a function of blade solidity and reaction across the blade row. Thus, this type of loss analysis enables an approximate predetermination of the over-all blade row loss as derived from fundamental boundary-layer concepts. In addition, it shows the effect on over-all blade loss of varying such design features as solidity and reaction.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):593-607. doi:10.1115/1.3662672.

A study has been made of the effects of free stream oscillations on laminar boundary layers of the Howarth type. Detailed measurements of oscillations have been made for the two conditions of Blasius flow and a Howarth flow fairly near separation. It has been found that there are three types of behavior, corresponding to low, intermediate, and high frequencies. Low and very high frequency oscillations are shown to be well described by existing approximate solutions. However, an intermediate frequency region required a new analytic treatment, the results of which do in fact account for the measured flow behavior in that region.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):609-621. doi:10.1115/1.3662677.

Experimental methods for the determination of certain statistical properties of turbulent conveyance and diffusion of solid particles in a gaseous state are presented. Methods include a tracer-diffusion technique for the determination of gas-phase turbulent motion and a photo-optical technique for the determination of motion of solid particles. Results are discussed and compared with previous analytical results.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):622-628. doi:10.1115/1.3662678.

Methods for treating a turbulent three-dimensional boundary layer at a plane of symmetry are presented. Reasonable agreement with experiment was achieved by the use of momentum integral techniques in the prediction of momentum thickness, shape factor, wall shear stress, and the location of separation.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):629-633. doi:10.1115/1.3662679.

The static and dynamic heat-transfer characteristics of several forms of hot-film element, used in flow measurement, are herein presented. These characteristics are defined in terms of external heat-transfer resistance and internal heat-transfer impedance, and from these terms the frequency response of a probe element is derived.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):635-642. doi:10.1115/1.3662684.

A method for determining the sonic velocity in a fluid as a function of pressure and temperature is described. The method used measures the time required for an expansion wave to travel a known distance through the test medium. The results of the sonic velocity measurements are presented for normal hydrocarbons from C6 to C16 for temperatures and pressures from 60 to 250 F and 0 to 5000 psig, respectively. The density of the hydrocarbons was also determined. The absolute viscosity of the test compounds was determined by use of a rolling-ball viscometer for pressures from 0 to 6000 psig in the temperature range given. Tabulated and graphical results are presented for adiabatic bulk modulus, density, and absolute and kinematic viscosity for the range of hydrocarbons tested.

Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):654-658. doi:10.1115/1.3662690.

When an axial fatigue specimen is subjected to repeated strain cycling about a fixed mean strain value, the mean stress decreases with the number of strain cycles. To explore this type of material behavior, tubular fatigue specimens of A-286 alloy have been axially tested under conditions of controlled strain, and the cycle-dependent relaxation of mean stress measured. Fatigue data for five initial mean stresses are also reported. It was found that, in the case of A-286 alloy, most of the relaxation occurred early in the fatigue life, especially during the first ten cycles.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):661-670. doi:10.1115/1.3662699.

Cast DCM and cast Udimet 500, two nickel-base alloys, were tested in a thermal-stress-cycling device of the Coffin type. The strains induced by the thermal stresses were analyzed in several ways in an attempt to relate the plastic strains to cyclic life. The plastic strains were too small to permit calculating them with sufficient accuracy to correlate with cyclic life. It was found, however, that stress range did correlate reasonably well with the number of cycles to failure.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):671-682. doi:10.1115/1.3662704.

During the course of an experimental investigation on the effect of cyclic plastic strain on metals [1], it was observed that under certain conditions materials subjected to cyclic plastic strain showed little stability to simultaneously imposed steady stresses. The present paper describes and interprets some experiments undertaken to learn more about this behavior of real materials.

Topics: Stability , Metals , Stress
Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):683-688. doi:10.1115/1.3662705.

This paper provides results of an analytical and computer investigation to determine the numerical coefficients involved in the roll-force and roll-torque equations pertaining to a single stand in a multistand, tandem, steel rolling mill. To the authors’ knowledge, such information has not appeared in the literature to date. The coefficients for a typical hot mill are compared with those obtained for a typical cold mill. The principles of gage control are discussed. The theories on flat-strip rolling are reviewed briefly.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):689-694. doi:10.1115/1.3662706.

Equations are developed for prediction of steady-state creep stresses and strain rates in a thick-walled tube under combined internal pressure and axial load. An analytical solution of the equations, in closed form, is not possible but numerical solutions to the equations are tabulated for various values of the variables. For values of the variables, other than those tabulated, interpolation is usually adequate. If this is not the case, a trial method of calculation is presented which uses the tabulated solutions as a starting point. Simple approximate solutions, which apply for the cases in which the additional axial load is small or large relative to the axial load due to internal pressure, are also given.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):695-708. doi:10.1115/1.3662708.

Experimental justification is presented for extending an existing rotating disk deformation theory-finite difference plastic flow calculation method to predicting the deformation and fracture of welded composite aircraft gas turbine wheels. Calculated deformations generally equaled but sometimes exceeded measured deformations. Fractures could be predicted for wheels containing no significant defects. Defects observed in fracture surfaces were incomplete penetration, incomplete fusion, porosity, and coarse columnar structure. Of these, incomplete penetration was significantly associated with losses in strength.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):710-713. doi:10.1115/1.3662712.
Abstract
Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):717-725. doi:10.1115/1.3662720.

An analysis of the viscosity effect on meter accuracy of an axial-flow turbine-type flowmeter is formulated by the use of physical reasoning and experimental evidence. This analysis indicates methods of compensating for the effect of viscosity on meter accuracy. One method of compensating for viscosity is analyzed and design criteria are developed for constructing a viscosity compensator. Test results of a turbine meter, before and after installation of a viscosity compensator, are presented for comparison with the results determined from analysis.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):729-733. doi:10.1115/1.3662726.

Tests have been conducted to determine the usefulness of the quadrant edge orifice as a fluid-metering device for low Reynolds number flow. As a result of numerous laboratory tests to determine the behavior of the discharge coefficient with changing Reynolds number, the following are discussed: The range of constant discharge coefficient, reproducibility of orifice plates, diameter ratio effects, upstream roughness effects, reinstallation effects, and effects of pressure tap location.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):735-738. doi:10.1115/1.3662729.

Present equations for calculating the flow coefficient in orifice metering are considered invalid for meters smaller than two inches. This paper develops a general expression for the flow coefficient in three-quarter and one-inch meters.

Commentary by Dr. Valentin Fuster
J. Basic Eng. 1960;82(3):741-753. doi:10.1115/1.3662735.

A method is presented for the calculation of stresses and deflections in ring-shaped shells of circular cross section, subjected to axial forces. The solution is derived without the restriction imposed for toroidal shells by previous investigators, that the radius of curvature of the cross section is to be small in comparison with the mean radius of the torus. The range of applicability of the method is extended hereby to include the slightly arched convolutions used in the construction of welded bellows. By a rational reduction of the general solution approximate design formulas are obtained for the maximum stresses and deflections in bellows under axial forces and the calculated values are compared with experimental data.

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

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