bluuebunny/crossref_metadata_2025 huggingface dataset:
Partial agonistic effects of pilocarpine on Ca2+ responses and salivary secretion in the submandibular glands of live animals
Authors: Nezu Akihiro , Morita Takao , Tojyo Yosuke , Nagai Takeharu , Tanimura Akihiko
Published: April 2015

New Findings

What is the central question of this study?

Pilocarpine stimulates salivary secretion via muscarinic ACh receptors (mAChRs), although the Ca2+‐mobilizing effect of pilocarpine in salivary gland cells is extremely small. Therefore, we examined the effect of pilocarpine on Ca2+ responses in submandibular gland cells and on secretion in vitro and in vivo.

What is the main finding and its importance?

Pilocarpine induces small Ca2+ responses and reduces the effects of other mAChR agonists on Ca2+ responses via its partial agonistic effects. These effects of pilocarpine on Ca2+ responses in the submandibular gland were further established in vivo with a novel Ca2+ imaging system and a genetically encoded Ca2+ indicator.

Pilocarpine stimulates salivary secretion via muscarinic ACh receptors (mAChRs), although the effect of pilocarpine on Ca2+ responses in dispersed salivary gland cells is extremely small. Here, we demonstrate the effect of pilocarpine on Ca2+ responses and salivary secretion in the rat submandibular gland (SMG). In fura‐2‐loaded SMG cells, the maximal effect of pilocarpine on [Ca2+]i elevation was 16% of that of carbachol, and pilocarpine attenuated carbachol‐ and bethanechol (Bet)‐induced [Ca2+]i increases, indicating that pilocarpine acts as a partial agonist for mAChR‐mediated Ca2+ responses. The partial agonistic effect of pilocarpine on Ca2+ dynamics in the SMG was also confirmed in live animals using the genetically encoded Ca2+ indicator, YC‐Nano50. Administration of pilocarpine (3 mg kg−1, i.p.) elicited a small increase in [Ca2+]i in the SMG. Quantitative analyses demonstrated that resting [Ca2+]i was ∼37 nm, which was increased by pilocarpine (3 mg kg−1) and Bet (10 mg kg−1) to 44 and 69 nm, respectively. The inhibitory effects of pilocarpine on Bet‐induced Ca2+ responses were also elucidated in vivo. We further examined real‐time changes in pilocarpine‐induced SMG salivary secretion and showed that pilocarpine induced an extremely weak secretory response and reduced Bet‐induced secretion. Unlike Ca2+ responses, pilocarpine failed to reduce the effect of Bet on SMG blood flow. Our results demonstrate that pilocarpine acts as a partial agonist of mAChRs to induce weak salivary secretion that is correlated with small increases in [Ca2+]i. Furthermore, pilocarpine exhibits an antagonistic effect on mAChR‐induced Ca2+ responses and salivary secretion.
Rapid Manufacture of Novel Variable Impedance Robots
Authors: Enoch Alexander , Vijayakumar Sethu
Published: April 2015

Variable stiffness and variable damping can play an important role in robot movement, particularly for legged robots such as bipedal walkers. Variable impedance also introduces new control problems, since there are more degrees of freedom to control, and the resulting robot has more complex dynamics. In this paper, we introduce novel design and fabrication methodologies that are capable of producing cost effective hardware prototypes suitable for investigating the efficacy of impedance modulation. We present two variable impedance bipedal platforms produced using a combination of waterjet cutting and 3D printing, and a novel fused deposition modeling (FDM) 3D printing based method for producing hybrid plastic/metal parts. We evaluate walking trajectories at different speeds and stiffness levels.
Fabrication of Rectangular Cell Ceramic Regenerators for Use in Gas Turbine Engines
Authors: Nielsen T. H.
Published: April 2015

A technique is described for producing rectangular cell ceramic honeycomb regenerators for use in heat engines. Extrusion-embossing of cordierite-filled thermoplastic sheet is the method used to produce disks. Compositions, fabrication parameters, and fabrication procedures are included.
Steam and Closed Gas Turbine Cycle
Authors: Buxmann J. , Griepentrog H. , Weber D.
Published: April 2015

The closed-cycle gas turbine has reached an advanced stage in its development and has proved to be a good economic and technical solution in the field of the combined generation of power and heat. This paper describes the advantages and development of the GHH Sterkrade plants in use.
Transonic Normal Shock-Turbulent Boundary Layer Interaction in Pressure Gradient Flows
Authors: Panaras A. G. , Inger G. R.
Published: April 2015

A basic theoretical analysis of the interaction of a transonic normal shock wave with a non-separating turbulent boundary layer in a background pressure gradient is given. The method is based on an extension of Inger and Mason’s small disturbance analysis to account for both explicit pressure gradients upstream and downstream of the interaction and the implicit pressure gradient effects on the local boundary layer shape plus the back-effect of the interaction-induced boundary layer thickness growth (blockage) that is important in channel flows and turbomachinery applications. The theory predicts the detailed disturbance pressure and skin friction distributions, including lateral pressure gradients, and is readily imbedded locally in a global calculation scheme involving transonic inviscid and boundary layer prediction codes upstream and downstream of the shock. Good agreement is found between the resulting theoretical predictions and experimental results for non-separating flows.
A Study of Commuter Aircraft Design
Authors: Galloway T. L.
Published: April 2015

Commuter airlines have generally demonstrated excellent growth in recent years. This growth has been accomplished mainly with aircraft that have evolved from larger general aviation aircraft or specially designed utility aircraft. None reflect a configuration optimized for the current type of passenger service early in the vehicle definition phase. This paper investigates the impact of configuration considerations, mission requirements, and performance constraints on conceptual commuter aircraft designs. Emphasis is placed on direct comparisons between turbofan and turboprop powered aircraft in the 10–30 passenger class. The analysis is accomplished using a computerized aircraft synthesis model that simulates the aircraft design and mission. The resulting conceptual aircraft are similar in size and performance regardless of engine type but the turboprop offers more mission flexibility.
Improving Turbo Compressor Efficiency via Performance Analysis Techniques
Authors: Scott J. N.
Published: April 2015

With the rapidly escalating price of fuel and diminishing supplies it is becoming necessary to improve the efficiency and optimize the use of turbine compression units. Some operating practices that were acceptable several years ago are now no longer tolerated because they are wasteful of fuel. In 1974 TransCanada PipeLines embarked on a unit performance testing program and this paper describes some of the areas in which substantial savings in fuel have been made through performance analysis.
Design and Manufacture of a Gas Turbine Rotor for Temperature and Vibration Measurements
Authors: Frei O.
Published: April 2015

A special gas turbine test rotor has been manufactured to measure compressor blade vibrations and turbine rotor temperatures. This will be used to provide experimental verification of design calculations. The design and manufacture of thermocouple and strain gage instruments are described.
Evaluation of a Premixed, Prevaporized Gas Turbine Combustor for No. 2 Distillate
Authors: Teixeira D. P. , White D. J. , Ward M. E.
Published: April 2015

Results of a series of tests on a prevaporized, premixed combustor to evaluate its emissions control potential while operating on No. 2 distillate oil are presented. The concept utilized the heat capacity of the combustor inlet air to absorb the heat of vaporization of the fuel. Tests were conducted at combustor inlet temperatures and pressures characteristic of current generation electric utility gas turbines (345 C and 10 atm). NOx emissions in excess of proposed EPA gas turbine standards (75 ppm at 15 percent O) were observed at the 10 atm pressure condition and are believed to be the result of incomplete evaporation of the fuel Attempts to increase vaporization rates by increasing inlet air temperature were limited by autoignition of the mixture in the fuel preparation ports.
Characteristics of an Anechoic Chamber for Fan Noise Testing
Authors: Wazyniak J. A. , Shaw L. M. , Essary J. D.
Published: April 2015

Acoustical and mechanical design features of NASA Lewis Research Center’s engine fan noise facility are described. Acoustic evaluation of the 1420-m (50,000-ft) chamber, which is lined with an array of stepped wedges, is described. Results from the evaluation in terms of cut-off frequency and non-anechoic areas near the walls are detailed. Fan models with 0.51-m (20-in.) diameters are electrically driven to 20,600 rpm in either the inlet mode (drawing air from the chamber) or exhaust mode (discharging air into the chamber) to facilitate study of both fore and aft fan noise. Inlet noise characteristics of the first fan tested, the JT8D Refan, are discussed and compared to full-scale levels. Turbulence properties of the inlet flow and acoustic results are compared with and without a turbulence reducing screen over the fan inlet.
NASA Quiet, Clean General Aviation Turbofan (QCGAT) Program Status
Authors: Bresnahan D. L. , Sievers G. K.
Published: April 2015

A two-phase program is being conducted by NASA’s Lewis Research Center to determine the suitability of large engine technology to reduce noise, emissions and fuel consumption of smal turbine engines and develop new technology where required. In Phase I, six-month study contracts were awarded to three manufacturers of small turbine engines to provide NASA with information required to prescribe the most effective experimental engine program (QCGAT) The results of this study phase showed reduced noise levels for the three engines at takeoff, sideline, and approach and emissions predictions that met the 1979 EPA standards for Class T1 engines. For the second phase, two contractors bid and both were selected to design, fabricate, assemble, test, and deliver experimental engines to NASA, The current status of this phase is discussed.
Aircraft Fuel Pumps: Where We’re at (A Review of Some Problems and Their Current Solutions)
Authors: Thompson J. S.
Published: April 2015

European-designed tank-mounted boost pumps, the thermal diffuser, engine driven backing pumps and gear pumps have all changed, and improved, over the last few years. This paper outlines the reasons for the changes, the problems they are designed to overcome, and the efficacy of the solutions offered.
Transpiration Air Protected Turbine Blades: An Effective Concept to Achieve High Temperature and Erosion Resistance for Gas Turbines Operating in an Aggressive Environment
Authors: Raj R. , Moskowitz S. L.
Published: April 2015

The future generation is looking forward to the use of gas turbine inlet temperatures as high as 3000 F (1650 C) with attendant thermal efficiencies of from 40 to 50 percent in combined cycle electric power plants. In addition to the use of high temperature for improved efficiency, the national needs, due to scarcity of oil and natural gas, will heavily stress the use of coal as a fuel. The particulate from combustion of coal derived liquid and gaseous fuels, even after employing hot gas cleanup systems, may damage conventional turbine blades and thus reduce turbine life. This paper is intended to show how a transpiration-cooled blade can cope with both of the foregoing problems simultaneously. The fundamental aspects of the transpiration-cooled blade technology will also be explained. Experimental results using this design concept indicate that significant erosion resistance is feasible for gas turbine blading in the near future.
The Closed-Cycle Turbine: Present and Future Prospectives for Fossil and Nuclear Heat Sources
Authors: McDonald C. F.
Published: April 2015

The closed-cycle gas turbine (CCGT) may well emerge in the foreseeable future as a major contributor to the U. S. electric utility industry because of: (a) its adaptability to coal-fired and to nuclear heat sources, (b) very high fuel utilization efficiency when the high grade waste heat is used, (c) potential for high degree of reliability and availability and low maintenance, (d) efficient, cost-effective dry cooling where no cooling water is available, and (e) an established technology base for commercial introduction into the power generation industry. In addition, the gas turbine HTGR provides a vehicle for demonstrating and developing the technology for economical nuclear process heat. In Europe, the closed-cycle gas turbine has demonstrated a high degree of reliability and availability, with both air and helium as working fluids. Power plants up to 50 MWe have operated successfully on a variety of liquid, gaseous, and solid fossil fuels. The waste heat thermal energy from these plants, in the form of hot water, has been used for urban and industrial district heating with the result that the fuel utilization efficiency has approached 80 percent, an impressive value indeed for an approaching era of energy conservation, where high power plant efficiency, and particularly high energy utilization effectiveness will be of the essence. In this paper, the established technology bases for closed-cycle gas turbines and high temperature gas cooled reactors (HTGR) are summarized.
Telemetry for Rotating Measurements on Turbomachinery
Authors: Adler Alan
Published: April 2015

In the past decade, the use of shaft-mounted radio telemetry systems, for measurements on the rotating components of turbomachines, has grown to maturity. This applications-oriented paper covers the following topics:

What is telemetry?

• Advantages and limitations

• Choosing between telemetry and slip-rings

• Designing a telemetry installation

• Conducting the engine test

• Forthcoming developments in telemetry.
Performance and Design of Transpiration-Cooled Turbine Blading
Authors: Bayley F. J.
Published: April 2015

This paper reports recent experimental and theoretical studies of transpiration-cooled turbine blades, and on the basis of this and earlier work in the total research program proposes a design method for such cooling systems. An integral boundary-layer method of analysis is shown to produce good agreement between observed and predicted heat transfer coefficients over most of the blade section where the effect of the coolant flow is significant, while a simple momentum-mixing theory appears adequate for assessing the effects of the coolant on the blade profile loss.
A Microprocessor Based Hierarchical Control System for Gas Turbines
Authors: Risch D. M. , Goar D.
Published: April 2015

Electronic controls are being used on more gas turbine engines today than ever before. Part of this has been due to the proven capability of electronics, and part has been due to the increasingly complex tasks that controls have been required to perform. Unfortunately, for industrial gas turbines, there has been little coordination between the various aspects of the total system: control, sequencing, monitoring, and annunciation. This paper describes a control system which has integrated all those functions into a hierarchical system that is both powerful and reliable. The key elements of the system are a microprocessor controlled programmable sequencer and a proven modular analog control system. A gas pipeline application will be explored in detail.
The Energy Saver Combined Cycle
Authors: Bernstein E. , Cashman J.
Published: April 2015

Combined-cycle plants are not new. The fuel crunch, however, is relatively new, forcing new economic considerations, evaluations, and designs. This paper presents a UTC modular industrial gas turbine/steam turbine combined cycle which is specifically designed around the new economics, with owning and operating costs the vital parameter, resulting in more efficient combined cycles in the 8000 Btu/kwhr range. Utilizing the modular concept results in a family of combined cycles to fit practically any load requirement.
A Combined System of Fuel Washing Involving Both Centrifuges and Electrostatic Separators: A Hybrid
Authors: Spalding E. G. , Krulls G. E.
Published: April 2015

In the gas turbine business, heavy fuels have traditionally been treated by plants using either centrifuges or electrostatic precipitators as water/fuel separators. These systems individually have certain disadvantages when applied to treating difficult heavy fuels, which can be overcome by combining the two systems whereby in the first-stage centrifuges are used followed by electrostatic precipitators in the second and subsequent stages of the treatment. The first part of the paper will deal with the Hybrid system itself, outlining its advantages, to be followed by a second part which will provide a description of the world’s first Hybrid plant which will have been built for Qatar. This plant has two stages, the first with seven centrifuges and the second with an electrostatic precipitator. Extraction of the salt in the oil to the wash water is brought about in both stages by a multi-stage rotary paddle type extractor which will also be described.
Design of a Pressurized Fluid Bed Coal Fired Combined Cycle Electric Power Generation Plant
Authors: Moskowitz S. , Weth G.
Published: April 2015

The combination of pressurized fluidized bed (PFB) technology and the gas turbine - steam turbine combined-cycle power system offer a unique opportunity for the production of electric power at increased plant efficiency from the direct combustion of high sulfur coal and that is environmentally acceptable without stack gas cleanup. The concept offers the prospect of earlier commercialization than those systems requiring gasification or liquefication of coal to clean fels. This paper presents the design of a 500-MW commercial powerplant prepared in conjunction with the U.S. Department of Energy sponsored program for the design, construction, and operation of a coal-fired PFB/turbine electric pilot plant. The powerplant approach develops over 60 percent of the plant capacity by multiple gas turbine gas turbine-generators and the balance of the capacity by a steam turbine-generator. The paper describes the fluid bed process selection of an air heater cycle. With two-thirds of the compressor discharge air indirectly heated within an in-bed gas-to-air heat exchanger and one-third of the compressor air involved in the combustion process, technology requirements for hot gas cleanup and turbine protection are minimized. This approach, which offers a coal-pile-to-busbar plant efficiency of over 40 percent is superior to other concepts and contemporary plants in terms of plant arrangement flexibility, part-load performance, power availability, and provides a low risk in development toward commercialization in the 1980’s.
Stresses in Turbine Blades due to Temperature and Load Variation
Authors: Mukherjee D. K.
Published: April 2015

During transient operation, gas turbine blades are subjected to cyclic thermal stresses. For the first-stage blade of a Brown Boveri gas turbine, time-dependent temperature and stress distributions are computed by finite difference method to determine maximum total strain and to predict blade life failure. These calculations together with similarity conditions result in allowed temperature range fluctuations as a function of cycle time for a particular damage. The influence of important parameters like Biot and Fourier number was determined. Thermal fatigue tests of these blades in fluidized beds were carried out to investigate their resistance and to ascertain the usefulness of the computation technique. The predicted number of cycles to failure agreed quite well to those found in fluidized bed.
Teaching of the Fluid Mechanics of Turbomachines
Authors: Lewis R. I.
Published: April 2015

Turbomachinery fluid mechanics theory has become so advanced in response to the demands of modern high technology machinery that practicing engineers and academics are presented with conflicting requirements. Engineering career progression requires increasing generalism, especially within the management structure of large companies. Advanced engineering produces, conversely, demands for skilled specialist from among the most able engineers. The conflict is reflected in first and second degree courses which primarily serve the broad training needs of engineers. Final year specialist student options and masters degree courses offer one solution to the necessary compromise needed, coupled to doctoral programs. Typical fluid dynamic topics are presented which commend the use of classical fluid dynamics as optimal for educational purposes. A new unified approach to performance analysis, which links dimensional analysis, velocity triangle selection, duty coefficient selection, and aerodynamics, is presented as the key to a coordinated approach to teaching and codification of this field of study. Sample syllabi and examination question are given.
Turbine Blade Tip Clearance Measurement Utilizing Borescope Photography
Authors: Chandler A. L. , Finkelstein A. R.
Published: April 2015

In this paper, a technique is presented for the detrmination of turbine rotor bade tip-to-stationary shroud clearance requirements utilizing fiber optics. To accomplish these tip clearance determinations, special rub pins were installed in the turbine shrouds, or tip-shoes, of a 10,000-hp engine. A test procedure was created based upon a transient dimensional analysis, and a cooled borescope and camera were developed. The clearances are presented from a series of successive engine tests.
An Evaluation Technique for Determining the Cost Effectiveness of Condition Monitoring Systems
Authors: George P. T. , Parker A. T.
Published: April 2015

A technique for analyzing the cost-effectiveness of condition monitoring systems has been developed both to provide a quantitative assessment of the value of condition monitoring and to guide the selection of items to be monitored by the system. The technique uses historical data combined with catalog cost estimating to estimate both the life cycle cost of the condition monitoring system and the potential cost savings offered by the system for commercial engines. The results are obtained in a form that can be easily converted to any of the primary cost-effectiveness parameters in current use by industry. Key to the technique is the definition of a series of condition monitoring system concepts of increasing complexity for analysis, with each increase representing a logical step with respect to cost-effectiveness. This feature permits the results of the cost-effectiveness analysis to be applied directly to the design definition process without iteration or further cost analysis.
Time-Phased Development Methodology: The Key for Reliable Engines in Future Military Aircraft Weapons Systems
Authors: Price J. L. , Gershon I. J. , Meece C. E. , McKenny L. D.
Published: April 2015

The development of gas turbine engines has been keyed primarily to increases in thrust-to-weight ratio and to greater demands for structural durability. In fewer than 20 years, the thrust-to-weight ratio of turbine engines has doubled, as demonstrated by the F100-PW-100 engine compared to the J75. Also, a new engine life parameter, low cycle fatigue, was recognized. This new parameter results from stress variations in the engine hardware during thrust level excursions and is now included in the latest engine Military Specification (MIL-E-5007D). Since current projections of propulsion systems for the next decade show a continuing trend of increases in thrust-to-weight ratio and required durability, highly sophisticated time-phased structural analysis and verification methodology is being developed [Reference 1] for future engine development programs. This methodology is intended to ensure that the risk of structural distress, which is a primary cause of “high-costs” during system development and after deployment is minimized, and to provide a reliable understanding of the systems structural capability to facilitate expansion of the overall weapons systems to counter new “threats.” The following discussion describes the principal features of the methodology developed.
Gas Compression in Combined Cycles With Gasification
Authors: Foster-Pegg R. W.
Published: April 2015

This paper is an investigation of the relative performance of combined-cycle power plants incorporating fuel gasification with different methods of gas pressurization to establish an order of merit of the compression systems. The type of raw fuel is not identified. The findings could apply to any likely feedstock for gasification, such as coal, residual oil, pitch, or maybe refuse. Compression systems for air-blown and oxygen-blown gasifiers are examined. In the cases of oxygen-blown gasification, the energy required by the oxygen plant is included in the evaluation. The fuel gas may be manufactured at low pressure and the gas compressed or the gas may be manufactured at high pressure, requiring that the oxidant used in the gasification be compressed into the gasifier. Both the above systems and combinations of the two wherein both oxidant and fuel gas are partially compressed will be considered. The study evaluates the various compression systems on a simplified basis to identify gross differences between systems. It is not the intention of the study to establish the relative merits of systems which are closely related in performance.
Alternative Closed-Cycle Gas Turbine System Design Considerations for Ship Propulsion Applications
Authors: Kuo S. C. , Shu H. T.
Published: April 2015

This paper discusses the major system design alternatives considered in a comprehensive system study of closed-cycle gas turbine propulsion systems for advanced ship propulsion applications. The general requirements and constraints applicable to propulsion engines for advanced ships were reviewed, and major design variances from the traditional land-based closed-cycle gas turbine power systems were identified. The potential impact of these system requirements and design variances will have on the selection of thermodynamic and mechanical design alternatives applicable to the power conversion system were evaluated, and some trade-off considerations, including the domain of optimal system design, are discussed.
Propulsion System Design for the Multi-Mission Patrol Ship Mark 1/1A
Authors: Bronson L. E. , Prentice R. M.
Published: April 2015

PSMM Mkl/1A is a high-speed patrol ship designed to accomplish a variety of missions. It is a 165-ft aluminum hull powered by six gas turbines driving two controllable reversible pitch propellers. Two-stage combining reduction gears with self-synchronizing clutches enable the ship to operate at speeds to 40 knots on from one to six turbines. Controllable pitch propellers are used to optimize operations in high- or low-speed maneuvers. The propulsion system is controlled by a pair of analog computers which automatically select shaft rpm and propellers pitch based on power command and the number of turbines operating. This paper will discuss the propulsion system and controls as designed, the modifications made during trials of the Mk1 in late 1974, and the improvements made in the Mk 1A and proved during trials in 1977.
Description and Performance of a 7000-Shp Marine Gas Turbine Engine
Authors: Strother J. R.
Published: April 2015

Detroit Diesel Allison (DDA) Division of General Motors Corporation, has developed a 7000-shp class gas turbine engine for industrial use. The engine uses proven modern technology which results in low-fuel consumption over a wide range of power and a compact installation envelope. Approximately 5000 hr of performance and endurance testing have been accumulated to date. Testing is continuing at DDA and the first-field installation was completed in September 1977 in a stationary air compressor application. It is anticipated that 10,000 hr of engine test experience will be gained prior to production unit availability in 1978. This paper discusses the mechanical arrangement, performance, control system, installation and maintenance features, and status of the Model 570 engine.
Limits of Rotating Stall and Stall in Vaneless Diffuser of Centrifugal Compressors
Authors: Senoo Y. , Kinoshita Y.
Published: April 2015

Based on the theory in Reference (3), the flow behavior is predicted in four vaneless diffusers with different geometries at the flow rates just before rotating stall and just before stall, which have been experimentally determined. Since the predicted velocity distributions at the critical conditions are physically reasonable for rotating stall and for stall are tentatively set so that the critical conditions are predictable using the theory. Prediction is made for two cases for backward leaning blade impellers and three cases for radial blade impellers in the literature in addition to the authors’ experiments. Satisfactory results are obtained except one example.
Recent Experience on Centrifugal Compressors for Small Gas Turbines
Authors: Beard M. G. , Pratt C. M. , Timmis P. H.
Published: April 2015

The design philosophy and development of three recent Rolls-Royce centrifugal compressors, ranging in pressure ratio from 3.6 to 7, are described. The main geometrical and aerodynamic details are given, together with overall performance characteristics of the compressors.
On-Site Generation of Hydrogen for Generator Cooling
Authors: Ruzz J. I. , Haemer E. J.
Published: April 2015

As generation costs continue to rise, utility combustion turbine users are increasingly receptive to the cost savings of on-site production of consumable materials, such as gaseous hydrogen, for use in electric generator cooling. This paper reviews the application of electrolytic hydrogen generation equipment on combustion turbine or steam turbine electric generator installations. Items discussed include the fundamental theory of electrolytic hydrogen generation, hardware configuration, system sizing and design considerations, space and utility requirements, economics, and maintenance considerations.
Marine Gas Turbines in the Royal Navy 1976–1978
Authors: Jefferis T.
Published: April 2015

The paper covers development and operating experience of the Olympus TM3B, Tyne RM1A and RM1C engines in the Royal Navy over the period 1976 to 1978. Problem areas that have been identified and their solutions are discussed and lines of related research and development in the fields of Combustion, Materials, and Engine Health Monitoring are indicated. The paper concludes that the decision of 10 years ago adopt all gas turbine machinery for future surface warships is being thoroughly vindicated by experience.
Making Turbofan Engines More Energy Efficient
Authors: Hemsworth M. C. , Zipkin M. A.
Published: April 2015

A review of transport aircraft gas turbine engine development and evolution during the past two decades is presented in terms of energy consumption. The interaction and effects of cycle pressure ratio, firing temperature, bypass ratio, and component efficiencies on installed fuel consumption are reviewed. The possibilities for further substantial improvement in energy efficiency with improved operating economics and with improved environmental characteristics are identified and evaluated. Parametric data are presented showing trade-offs in the areas of efficiency and economics. Environmental considerations are also discussed. The balance of these factors in a cost-effective advanced turbofan is discussed. In conclusion, projections are made for the capability of an advanced turbofan engine compared with the goals established by NASA for their Energy Efficient Engine Program. The characteristics of this more efficient, cost-effective power plant, that can be operational in the late 1980’s, are shown in relationship to current turbofan engines.
20 HP Mini-RPV Demonstrator Engine Programs
Authors: Johnson E. T. , Smith K. F. , Marstiller J. K.
Published: April 2015

This paper presents the selection, design, and intial test of two 15 kw (20-hp), two-cylinder, two-stroke demonstrator engines for use on mini-RPV aircraft. The objectives are: (a) to provide a technology base for mini-RPV engines, using current high-production components; (b) to identify areas where future development and procurement costs can be reduced without compromising the propulsion system’s ability and survivability of the concepts. Future development work must, therefore, be aimed at applying this technology base to a propulsion system design to meet specific mini-RPV applications.
A Computer Program for the Design of Turbomachinery Blades
Authors: Engeli M. , Zollinger H. J. , Allemann J. C.
Published: April 2015

In the design of turbomachinery blades, it is highly desirable that the second derivative of the profile shape is continuous. To meet this requirement, the present method uses Bernstein polynomials to describe the surface of the blades. Pressure and suction sides are formed of one segment each to ensure a continuous surface. The analytical description of the blade offers many advantages in a computer-aided design process, because any geometrical operation — intersection with other bodies, rotation, displacement and projection — is relatively simple. The design program is written in the EUKLID programming language which was developed for elegant and simple treatment of geometrical problems. For example, the language includes standard routines for vector operation, intersection of bodies and various graphical displays. Punched tape for NC machines can be generated. With an example, the design process for a turbine blade is explained and the different capabilities of program are demonstrated.
Bearing Compartment Seal Systems for Turbomachinery in Direct-Cycle HTGR Power Plants
Authors: Adams R. G. , Boenig F. H. , Pfeifer G. D.
Published: April 2015

The direct-cycle High-Temperature Gas-Cooled Reactor (HTGR) employs a closed gas-turbine cycle with the primary reactor coolant (helium) as the working fluid. Design studies on this type of plant, carried out since 1971, have demonstrated, among other points, the advantages of the integrated arrangement, in which power from the cycle is transmitted to the electric generators by turbomachines completely enclosed in the reactor pressure vessel. A result of this arrangement is that the bearings are entirely enclosed within the primary coolant system of the reactor. An important aspect of the design of the turbomachinery is its prevention or minimization of the ingress of lubricants into the primary coolant system and its prevention of ingress of primary coolant into the bearing compartments. The design studies, which included thorough conceptual designs of the turbomachinery with emphasis on bearings and seals and their support systems, showed that total exclusion of lubricant requires extremely complex seals and seal support systems. The variation of system low-end pressure with control actuation and the requirement that the bearing cavity pressure follow these variations were proved to further complicate the service system. This paper discusses the aformentioned problems and their solutions in tracing the design evolution of a satisfactory bearing-compartment seals and service system. The resulting system appears to be feasible on the basis of experience with industrial gas turbines.
Aerodynamic Development of Stages for Industrial Centrifugal Compressors: Part 1 — Testing Requirements and Equipment — Immediate Experimental Evidence
Authors: Benvenuti E.
Published: April 2015

Availability of centrifugal compressor stages having a wide variety both of geometric features and performance characteristics is required for manufacturing multi-stage industrial process compressors. Optimizing and reliably predicting stage performance requires the availability of suitable experimental aerodynamic data. Features and capabilities of rigs designed for systematically testing single-stage configurations are described; testing guidelines and requirements associated with successive use of results for both manufacturing design and development purposes are outlined. The complexity of flow fields existing on some relevant gas flow-path areas is shown for evaluating measurement reliability and outlining the nature of major problems specific to industrial compressor stages.
A New Concept for the Development of Coal Burning Gas Turbines
Authors: Schilling H. D. , Schreckenberg H. , Wied E.
Published: April 2015

Pressurized fluidized bed combustion offers a promising chance of realizing the coal burning gas turbine. This paper deals with a German development and describes the design and layout of a pilot plant.
The Compact Industrial Gas Turbine Recent Technical Improvements
Authors: Mottram A. W. T.
Published: April 2015

The industrial gas turbine requires continual improvement in order to increase output and efficiency, to extend its life and to meet fresh environmental requirements. In the compact industrial gas turbine, derived from the aircraft engine, the required improvements are achieved in three ways: (a) new features are incorporated which have been developed to meet the specific requirements of industrial applications, (b) technical improvements developed initially for aircraft engines are applied to existing industrial engines, and (c) new engines developed for aircraft and to a higher technical standard are introduced into industrial service. This paper describes recent improvements to Rolls-Royce compact industrial gas turbines with particular reference to the Olympus C and Olympus 593.
Development of the Garrett GTPF990: A 5000-Horsepower Marine and Industrial Gas Turbine Engine
Authors: Wheeler E. L.
Published: April 2015

The Garrett GTPF990 gas turbine engine is being developed under a U.S. Navy contract to fulfill both propulsion and generator drive repuirements. This is a unique second-generation marine engine that is not derived from an aircraft engine counterpart. The engine development is nearing completion, endurance testing has started, and all other qualification testing has been conducted. This paper is a development status report. A description of the engine and special maintenance features is presented. Emphasis is placed on qualification test results, development test experience, and the resulting design improvements.
Simulation of Helicopter Powerplant Performance
Authors: Baxendale B. V. , Inglis M. E.
Published: April 2015

Programs have been written for a hybrid computer to simulate in real time the dynamic behavior of the engines, airframe, and rotor systems of the Sea King and Lynx helicopters; their purpose is to aid the study of performance and control of helicopter power plants. Since the engines are directly coupled to the lift-producing surface (the rotor), it is important to take proper account of the interactions between the power plant and the rest of the aircraft; however, for this type of work, it is reasonable to limit simulated aircraft maneuvers to three degrees of freedom in a single vertical plane. The method of simulating the major features of the helicopter are discussed, along with their implementation on the hybrid computer. The paper goes on to describe the successful validation of the two models by comparison with specially obtained flight data on a range of rapid maneuvers involving large changes in power demands. Finally, a description is given of an exercise on the Sea King simulation to investigate the effect of an engine or control system failure at a critical flight condition.
Military Engine Usage Monitoring Developments in the United Kingdom
Authors: Hurry M. F. , Holmes M.
Published: April 2015

The application of engine usage monitoring systems in U. K. military aircraft for the purpose of reducing life cycle costs is discussed. Recent developments in the airborne recording equipment and ground data processing facility are described, and some results from analysis of recorded flight data aimed at identifying component fatigue life consumption are presented. The use of equipment dedicated to component life monitoring is discussed and the development of a low cycle fatigue counter is described in more detail. Finally, the prospects for extending engine usage monitoring equipment to take advantage of future developments in microelectronics are considered.
Economic Evaluation Technique of Selecting Turbines for Natural Gas Pipelines
Authors: Hajnal T. E.
Published: April 2015

Designers of natural gas transmission systems often have to make recommendations as to the type, size, and number of turbines to be purchased and installed either on new pipelines or on expanding existing systems. This paper describes the economic evaluation technique which is being used by TransCanada PipeLines, of selecting turbines for natural gas transmission pipeline systems. The technique is based on comparing the present worths of annual owning and operating costs associated with the turbines considered for installation.
Preliminary Design of Three Combustion Concepts to Burn Low Btu Coal Gas in a High Temperature 1600 C (3000 F) Combustion Turbine
Authors: Dibelius N. R. , Touchton G. L. , Vogt R. L.
Published: April 2015

This paper presents the preliminary design of three different combustors for a high temperature turbine to burn low Btu coal gas at a firing temperature of 1425 C (3000 F), The turbine is to flow 700 lb of air per second at 16 to 1 pressure ratio.
Measurement of Emissions Variability of a Large Turbofan Aero-Engine
Authors: Lister D. H. , Wedlock M. I.
Published: April 2015

Emmission measurements of carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen (NOx) have been carried out on 12 Pratt and Whitney JT9D-7 turbofan engines after overhaul, and the effect of ambient conditions and engine to engine variation has been examined. Semi-theoretical correction factors, based on combustor inlet conditions, have also been applied to the data and a reduction in data scatter of better than 50 percent has been demonstrated. Average EPAPs for CO, HC, and NOx, have been determined: these are 13.9, 5.9, and 5.3 and bear a close relationship to other published data. Tests using both a fully thermostatted (423 K) or an uncooled probe have shown no observable differences in the measured emission levels.
Evaluation of a Water-Cooled Gas Turbine Combined Cycle Plant
Authors: Caruvana A. , Day W. H. , Manning G. B. , Sheldon R. C.
Published: April 2015

General Electric initiated the development of a water-cooled gas turbine in the early 1960’s. The first laboratory model of a water-cooled rotor, 9.7 in. (24.7 cm) was successfully tested in 1973 at sustained firing temperatures of 2850 F (1556 C) and 16 atm pressure while maintaining bucket surface temperatures of 1000 F (583 C) or less. Maximum firing temperatures of 3500 F (1927 C) were also attained during this period. The Electric Power Research Institute (EPRI) funded initial preliminary design work which utilized the water-cooled turbine concept in a combined cycle starting in 1974. Development work to define and resolve potential barrier problems was also funded by EPRI in the original and subsequent follow-on contracts. The United States Energy Research and Development Administration (ERDA) awarded a contract to the General Electric Company in May 1976 to conduct a preliminary design study which incorporates the water-cooled gas turbine concept in a combined cycle plant. The design is based on a gas turbine firing temperature (gas temperature entering the first-stage buckets) of 2600 F (1427 C) utilizing a coal-derived low-Btu gas or coal-derived liquid. This paper presents the results of the ERDA Program. Particular emphasis is devoted to the description of the overall plant design and performance. Turbine subsystems of the water-cooled concept and the alternate cooling concepts considered are also presented in this paper. The operating features and characteristics of an advanced fixed-bed gasifier and associated gas cleanup systems are also discussed relative to the impact on the overall system design and performance.
A Simple Method for the Prediction of Wall Temperatures in Gas Turbines
Authors: Kretschmer D. , Odgers J.
Published: April 2015

The cited method predicts wall temperatures generally within an accuracy of ± 6 percent, The biggest single factor governing the wall temperature is shown to be the hot gas temperature. Other factors discussed are the effects of changes in inlet temperature, fuel types, the geometry of the film cooling devices and manufacturing tolerances. Empirical formulas are given for the prediction of effective temperatures within the various combustor zones. Some comparisons are made between predictions and measurements of wall temperatures over a range of operating conditions.
An Automated Method for the Continuous Determination of Total Sodium in Fuel Oil
Authors: Giering L. P.
Published: April 2015

Fuel oils are frequently contaminated with sodium salts. Users of gas turbines are concerned with the level of sodium in fuel because of the deleterious effects to the turbine. Until recently, on-line continuous methods of analysis did not reliably measure the total sodium in a given fuel. A method is described for the continuous analysis of total sodium present in fuel oils regardless of its chemical form. A small amount of surfactant, “Liquid G” is added to the fuel, and the total sodium in the resulltant solution is determined by flame photometry. The method described provides for the continuous and reliable measurement of sodium in fuel.
Profile Loss Characteristics and Heat Transfer of Full Coverage Film-Cooled Blading
Authors: Hempel H. , Friedrich R.
Published: April 2015

In the present study, a blade was tested in the hot gas cascade of the Institut für Thermische Strömungsmaschinen (ITS), for determination of the loss characteristics and heat transfer of full-coverage film-cooled blading. The blade was equipped with staggered arrays of discrete holes spaced seven and 10 dia apart, an injection angle of 30 deg and hole diameters of 0.2 mm. The present study had two major objectives. First, an attempt was made in developing and testing a model capable of predicting the coolant flow rates as a function of the various geometric parameters such as hole distribution, radial coolant channel cross-sectional area distribution and the properties of the coolant. A relatively strong dependence of the cooling air flow rate on these parameters was found leading to a coolant flow strongly varying with blade height. In the second phase of the investigation, the blowing rate distribution at constant surface temperature, pressure distribution, wake profile, and profile losses under moderately high inlet temperatures were determined. Results are presented for cascade inlet Mach numbers of 0.18 to 0.26 and overall cooling to main airflow ratios of 1 to 3 percent and compared with available data. It was found that profile losses increase by about 100 percent in approaching and overall blowing rate of 3 percent. In comparing cold runs with those under hot gas conditions, profile losses were shown to be less dependent on the blowing rate and considerably smaller at low temperatures due to higher Reynolds numbers. At low cooling airflow rates, profile loss coefficients were smaller at lower main airflow Mach numbers, an effect which is reversed at higher blowing rates. This essentially agrees with previous measurement.
Ferris Wheel Testing: Low Cycle Fatigue Test of Gas Turbine Engine Discs
Authors: Jimboh K. , Aono H. , Kawashima T.
Published: April 2015

An overview of the disk life prediction and verification program, which includes very special disk fatigue test equipment called the Ferris Wheel, is described. This rig has been designed to simulate the effect of centrifugal force of blades on jet engine disk and is capable of doing LCF test in a very short time; (the period required for a Ferris Wheel test is one tenth that of a cyclic spinning test). This feature enables us to evaluate actual disk LCF life statistically and improve the reliability of disk LCF life predicted. An example problem is also included and the procedure of the evaluation of the disk life described in detail.