A Different Approach to Gas Turbine Exhaust Silencing

A unique method for silencing heavy-duty gas turbines is described. The Switchback exhaust silencer which utilizes no conventional parallel baffles has at operating conditions measured attenuation values from 20 dB at 63 Hz to 45 dB at higher frequencies. Acoustic testing and analyses at both ambient and operating conditions are discussed.

Design of a 65,000-Hp Heavy Duty Two-Shaft Gas Turbine

This paper describes the design of a 65,000-Hp heavy duty gas turbine for marine service, for land-based mechanical drive applications and for 50 Hz power generation. Operating experience of generically similar units was used to establish the high level of reliability and maintainability incorporated into this unit. This model series gas turbine will be available for commercial application in 1974.

Recent Status on Development of the Turbofan Engine in Japan

Efforts to design and develop new jet engines have been made in Japan since 1953. One family of propulsion engine (J3) succeeded in getting into production to be installed on two models of Japanese developed aircraft (T1B and P2J). Another family of lift engine (JR) has been successfully used for overall VTOL system studies. Based upon these experiences, studies on a new fan engine for main propulsion are being carried out. This new engine (FJR-710) is a high bypass front fan engine developed for low noise generation and low smoke emission.

Calculated Ground Level Concentration of Pollutants From Gas Turbine Using an Air Quality Display Model Computer Program

This paper contains the calculated ground level concentrations of air pollutants from 11 gas turbine models. These calculations were made using Charlotte, N.C. meteorological data. Four of these are simple cycle machines covering a range of size from 5050 hp to 65 MW and four are regenerative machines. Another three are combined cycle (STAG) machines, two machines having unfired and one having a fired heat recovery steam generator. The calculations were made using a slightly modified version of the United States Environmental Protection Agencies Air Quality Display Model Computer Program.

Experiences With Gas Turbines Burning Non-Refined Fuel Oils and Related Theoretical Investigations

This paper presents experience on large, low firing temperature European gas turbines operating on crude and residual fuels. The most economic fuel can be a distillate, a heavy distillate, a crude oil, and, in some applications, even a residual fuel.

Gas Turbine Internal Inspection With Minimum Disassembly

Borescope techniques offer an opportunity to evaluate internal gas turbine condition with minimum disassembly and outage time. As part of an overall maintenance evaluation program, the Borescope is an additional tool available to the Maintenance Planner in reducing cost and increasing equipment availability and reliability.

Protective Systems for Gas Turbines in Industry

Modern heavy-duty gas turbine installations employ a comprehensive system of protective circuits to provide needed equipment protection without jeopardizing plant reliability. The design of these circuits and the overall protective system philosophy are discussed to illustrate how protection and reliability are maximized. Experience gained to date on the application of these protective circuits also is reviewed.

Turbines and Trained Crews

Equipment knowledgeable operators and maintenance personnel are a valuable asset that will increase Gas Turbine availability and minimize outages and repair costs. A continuing training program is essential to maintain proficiency levels and upgrade new employees. The training program must be properly planned and constructed to accomplish this most effectively.

Some Results From Tests on a High Work Axial Gas Generator Turbine

Aerodynamic test results are presented for a single-stage, axial gas generator turbine of 3.9:1 design pressure ratio. Test results are also shown for a number of variants on this design, indicating the effect on aerodynamic performance of degree of reaction, nozzle and rotor aspect ratio, rotor blade channel design, rotor tip clearance, radial work distribution and effect of nozzle endwall contouring. Detailed aerodynamic observations are compared with analytical predictions. Of the design parameters examined, rotor blade aspect ratio, tip clearance and channel diffusion were found to have the greatest influence on losses. Operation at pressure ratios above the design was found to be improved with “open” rotor stagger, yielding a reduced design point degree of reaction.

A Model of Convex Programming for Turbojet Main Parameter Selection Optimization

A mathematical modeling of well-known methods used to define turbojet main parameters aiming at solution optimization is described. The parameters considered include: compression ratio, maximum temperature for turbine, compressor efficiency, turbine efficiency, etc. By using the relationships for specific thrust, specific fuel consumption, etc., and assuming that construction and functional parameters such as calorific value, combustion efficiency, flight altitude and speed, etc., are known a function representing a sum of the ratios describing specific thrust and SFC deviations against maximum specific thrust and minimum SFC, respectively, is derived. Main parameter selection criteria pending on engine operation conditions and aircraft category are introduced. Mathematic analysis for main parameter selection optimization leads to a convex programming model for which both the function and the constraints are convex functions defined by convex fields. Although this paper makes reference to classic jet engines the method may be easily developed for by-pass engines, etc.