Fluid Film Bearing Housing Design for a Hot Ambient Environment

Industrial gas turbine rotors sometimes require a journal bearing in a region of the machine surrounded by compressor discharge air. Ambient temperatures in this region may exceed 600 F (588 K), which poses a challenge to bearing designers. The present paper describes housing design approaches to meeting this challenge, an experimental program to evaluate them, and the application of results to operating field units. The experimental program was carried out in a special test facility on full-size housings for a 14-in. journal bearing in a hot, pressurized environment.

Fault Analysis of a Gas Turbine HTGR

The Gas Turbine High Temperature Gas-Cooled Reactor combines a helium-cooled reactor core of established design with a closed-cycle helium turbine power-conversion system. This paper discusses the design considerations which mitigate the consequences of failure of the rotating machinery located within the reactor vessel. The methods of analysis and summary of results are presented for the failure modes of most concern. The spectrum of potential incidents which have been evaluated include turbine blade, rim, and disk failures. The requirements and design methods for rotor containment are discussed. The turbomachine maintains a pressure ratio of about two between the high and low pressure portions of the loop; postulated failures can, therefore, lead to rapid rates of pressure change. The preliminary evaluation of this internal pressure equilibration is presented.

Advanced Composite Fan Blade Flight Evaluation Program

The preparation for and conduct of the first flight by the U. S. Air Force of a turbine engine fan stage fabricated of advanced composite materials is discussed. Composite material properties and basic design philosophy is presented along with preliminary flight evaluation results. This is the first application of filamentary-reinforced metal matrix composites to a turbine engine structural component.

Study of Light Weight Turbine Transmission Systems

Several transmission systems that are applicable to advanced marine vessels were investigated to determine if drives other than right-angle gearboxes would be practical in transmitting 50,000 (37.3 NW) hp from dual gas turbines downward through a vertical distance of 20 (6.10 m) ft to a propeller drive shaft. These systems included: hydraulic power, chain drive, steel tape drive, and a slider crank drive. Results of this survey indicated the right-angle bevel gear drive was the optimum system considering our present state-of-the-art. Further investigation was performed to optimize turbine and gearbox arrangement using weight, reliability, efficiency, serviceability, technical risks, and relative cost as the determining factors.

A Method for Calculating Cascade/Channel Endwall Boundary Layer Crossflow

A method is proposed for calculating cascade / channel endwall boundary-layer crossflow. It is based upon a numerical solution of the simple radial equilibrium equation for curved channel flow in the boundary layer with a foreknowledge of the mainstream boundary-layer conditions. The results consist of crossflow pathline patterns through the channel at various depths of the mainstream boundary layer complete with crossflow velocity and direction at any point in the channel. Secondary losses based on the crossflow energy plus the exit dump loss effect of the fluid collected in the corner vortex are shown to be calculable. The method is tested on two sets of published measurements for circular arc channels of turnings over 60 deg. Very good correlation of crossflow velocity in Johnston triangle form is indicated. An additional calculation method for tangentially moving endwalls, such as stator hub or rotor shroud, is presented for cascade geometries. Calculated results are presented for a highly loaded stator of 45-deg turning and the rotor of a 7.5:1 PR centrifugal compressor stage. The method is shown to successfully calculate the measured exit flow angle distribution for the stator.

PACE 260 at Comanche, the First Two Years

This paper describes the operating experience with the Westinghouse PACE 260 Combined Cycle Power Plant at Public Service Company of Oklahoma’s COMANCHE Station. This plant was the first PACE 260 unit to go into operation and had many new design features in the major components. The paper deals mainly with the problems that occurred and their solutions.

Air Inlet Filtration for Gas Turbine Units

Gas Turbine operators are constantly seeking ways and methods to reduce maintenance cost and extend availability of their units. One method, the use of air inlet filtration, is discussed in this paper. A test of inlet filtration was conducted to solve a unique ingestion problem, but other benefits were also discovered.

The Effect of Variable Geometry on the Operating Range and Surge Margin of a Centrifugal Compressor

Two variable geometry techniques have been applied to a small turbocharger compressor, with the objective of trying to move the peak pressure ratio operating point to lower flow rates, thereby yielding a broad flow range map. Variable prewhirl guide vanes and variable vaneless diffuser passage height have been studied separately. The results obtained with both techniques are compared and the relative merits and demerits with respect to improved flow range and isentropic efficiency penalties are considered.

Effect of Maintenance on Gas Turbine Reliability

The importance of reliability is discussed with its relationship to a gas turbine power generation site and the impact of maintenance on reliability, spare parts, site personnel, and equipment. A case history is presented to show how maintenance has improved the reliability of the site. It relates the experiences learned from start-up to today. Areas of major concern are the site personnel concept of maintenance and how it has changed, how maintenance programs have expanded, and the effect of these changes on reliability.

Advancements and Application of Programmable Analog Control Technology

The advantage of rapid control system adjustment is assuming increasing importance in the development of automotive gas turbine engine development. Digitally programmed analog controllers are particularly suited to these purposes, and the basis of operation of controllers of this type is explained. The detailed operation of an early development controller, type PAC 120, is described briefly and the operational short-comings of the unit are discussed. The incorporation of features 10 provide an improved unit, type PAC 250, having significant increase in capability is examined and the resultant controller is described. The application of the PAC 120 to some selected control problems of an automotive turbine engine are described. Finally, the application of the PAC 250 controller to the complete control of the power plant, including start-up and shutdown of the engine, is examined. It is concluded that the programmable analog control concept is a uniquely powerful development tool for this type of application.