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RESEARCH PAPERS

J. Eng. Power. 1964;86(1):1-5. doi:10.1115/1.3675413.

A method of determining overall cascade performance by means of torque measurements on a wheel with axial outlet is given. The method, which is believed to be new, is particularly suited for small axial turbines or compressors. It gives the overall performance in actual turbomachines and includes all losses. The method is simpler and gives more accurate results than the elaborate method of traversing, for instance, in small axial turbomachines with blade height below 0.1 inch. A one dimensional analysis is given and applied to two known flow conditions in order to obtain a comparison with other ways of evaluating these flow conditions. The relationship between cascade efficiencies defined in different ways is shown, and an illustrative example is given.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):7-12. doi:10.1115/1.3675427.

The design of supersonic turbine nozzles and rotors is discussed and a series of four supersonic turbine nozzles, which is believed to be of a new type, was built and tested. The ratio A/A* between the outlet flow area and the throat area varied between 3.64 and 1. Four axial turbines with these nozzles and with the same rotor were tested over wide ranges of pressure and speed ratios. These turbines were of impulse type. The influence on mass rate of flow and efficiency of Reynolds number and axial distance between stator and rotor is given. Stator and rotor efficiency, Mach numbers, and flow angles, as well as other flow quantities, are obtained by means of a wheel with axial outlet.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):13-16. doi:10.1115/1.3675408.

Four different axial, impulse turbines with extremely low aspect ratios (between 0.07 and 0.70) were tested over wide ranges of pressure and speed ratios. The influence on mass rate of flow and efficiency of Reynolds number and axial distance between stator and rotor is given. Stator and rotor efficiency, Mach number, and flow angles, as well as other quantities, are obtained by means of a wheel with axial outlet. Semiempirical formulas are given for turbine efficiency, stator efficiency, and rotor efficiency as functions of aspect ratio.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):18-28. doi:10.1115/1.3675412.

A modified actuator disk analysis is made which, through an improved prediction of the blade forces, attempts to give closer correspondence with experiment than the previous theory. The fluid is assumed inviscid and incompressible. Perturbations to the two-dimensional flow through an isolated blade row are considered. The steady flow equations of motion and continuity are linearized. According to experiments conducted on an isolated compressor rotor, the present theory offers an improvement, compared to previous theory, in the prediction of distortion attenuation, effects of flow rate, and effects of varying chord/spacing ratio.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):29-49. doi:10.1115/1.3675414.

Operational figures of some Brown Boveri gas-turbine installations classed according to the fuel burned: oil, blast furnace gas, natural gas. Corrosion and contamination of gas-turbine blades, laboratory and pilot tests, general considerations, fuel oils obtainable, their ash content and composition, and their suitability for use in gas turbines. Effect of the ash content and ash composition of liquid fuels, and of the dust content and dust composition of gaseous fuels on the life of the blading material. Drop in output and efficiency with time. Reduction of the rate of contamination of the blades by additives in the fuel. Experience with natural gas-fired gas turbines. Plant maintenance costs.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):50-56. doi:10.1115/1.3675415.

The generally used boiler efficiency concept is not convenient when combustion air is not varied in direct proportion to fuel. This situation may arise, for example, if combustion is being performed in gases exhausted by a gas turbine and the flow of these gases is determined by the requirement to carry a definite load on the gas turbine. This paper outlines a method of calculation alternative to the normal boiler efficiency method whereby the heat content in effluent gases from a combustion process such as stack gases may be divided into losses associated with the combustion air and a loss proportional to fuel. Some heat-balance calculations of a hypothetical cycle are included in an Appendix to demonstrate use of the method.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):57-61. doi:10.1115/1.3675416.

The silencing of gas turbine installations is primarily a problem of attenuating the noise from the atmospheric inlet and the exhaust openings except where installations are made in residential or rural areas in which case the sound from the gas turbine enclosure, auxiliaries, and driven equipment must also be included as part of the silencing program. The subject matter of this paper is limited to the inlet and exhaust openings. The amounts of attenuation that can be obtained from natural factors such as divergence, directivity, air attenuation, and duct configuration are given and graphically shown. The sound absorbing qualities of baffles for the absorption of sound in the eight octave bands is described. At elevated temperatures, the performance of baffles at any octave band must be adjusted to the wavelength at the elevated temperature. Airflow characteristics are designed to be compatible with turbine operating efficiencies. Accepted fabrication practice is described and mechanical performance standards recommended. Properly designed silencers incorporate structurally adequate and durable casings, balanced sound attenuation, and pressure drops that will not adversely affect turbine performance.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):63-73. doi:10.1115/1.3675420.

Recent investigations have moved a step closer to an understanding of real fluid phenomena in turbomachines by studying rotational flow once it has been established by viscous stresses and nonuniform exchange of energy. The present paper presents a more generalized mathematical treatment of rotational flow (Part I) and makes use of the equations developed to analyze experimentally observed phenomena in the impeller (Part II) and the diffuser (Part III) of a compressor. These studies show that induced vorticity in the impeller produces a nonuniform energy exchange which is the basis for additional rotational effects in the diffuser. Also the amount of vorticity generated varies with flow rate which increases the sensitivity of downstream components to changes in flow rate and thereby reduces compressor range. In the particular diffuser studied, the flow conditions, up to the point of separation, were all established primarily by the induced vorticity while shearing stresses next to the wall seemed to have a negligible influence. Downstream from the beginning of separation, however, an apparent shift in energy distribution is observed which could not be accounted for by the analysis. It is demonstrated that separation is detrimental to vaneless diffuser performance only if it is located at the diffuser discharge. Since the location of separation is a function of the vorticity induced, which varies with the flow rate, a widely spaced diffuser can have substantial variations in performance with a significant influence on the compressor characteristics.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):77-82. doi:10.1115/1.3675426.

This paper describes a method of analysis of the stresses in a hydraulic turbine stay ring which includes the effect of the bending moment applied to the stay vanes by the forces on the ring due to the membrane load of the spiral case, the pressure on the face of the ring, and the head cover load. In most cases the bending stresses in the stay vanes, previously neglected, are shown to be of substantial magnitude. These bending stresses can be reduced by proper positioning of the stay vanes within the stay ring structure.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):84-88. doi:10.1115/1.3675433.

A reversible axial-flow pump-turbine should have symmetrical airfoil sections on runner blades and diffuser vanes. A theoretical method is given which leads to an efficient use of such sections under all operating conditions. Some general charts have been prepared and these can be used for initial design considerations.

Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):89-94. doi:10.1115/1.3675434.

Due to the relatively high speed of present day reciprocating compressors, sensitive, high-speed, electronic instrumentation is required to obtain accurate indicator cards. Due to the high accuracies required, such instrumentation is usually specialized in that it serves only the purpose of engine indicating. This paper describes the use of general purpose, multichannel, dynamic measuring equipment to obtain a pressure-time indicator with superimposed suction and discharge pressures. In addition, a simple mechanical linkage pressure-time to pressure-volume converter is described which has been useful in eliminating a tedious data replotting process. The accuracy of the program appears to be within three percent.

Commentary by Dr. Valentin Fuster

DISCUSSIONS

J. Eng. Power. 1964;86(1):12. doi:10.1115/1.3675406.
FREE TO VIEW
Abstract
Topics: Turbines
Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):12. doi:10.1115/1.3675407.
FREE TO VIEW
Abstract
J. Eng. Power. 1964;86(1):16-17. doi:10.1115/1.3675409.
FREE TO VIEW
Abstract
Topics: Turbines
Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):17. doi:10.1115/1.3675410.
FREE TO VIEW
Abstract
Topics: Turbines
Commentary by Dr. Valentin Fuster
J. Eng. Power. 1964;86(1):62. doi:10.1115/1.3675419.
FREE TO VIEW
Abstract
Topics: Gas turbines
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster

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