bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three Component Velocity Measurements in the Interblade Region of a Fan
Authors: Menon Rajan K. 
Published: March 2015

Optimizing aerodynamics and improving blade designs to make efficient power-generating machinery requires a good understanding of the rotor flow field. Swirl, flow instabilities, and high turbulence highlight the need for understanding the three-dimensional nature of the flow. Dynamic interaction between fluid and structural aspects in fluid machinery, impact of unsteady flows or loads, and enhancement of property transport can be studied through simultaneous measurement of three components of velocity.
A three color, three component Laser Velocimeter System is used to simultaneously measure the three orthogonal components of velocity in the interblade region of a fan. The non-invasive nature of the technique combined with the very small measuring volume of the system provides detailed mapping of the flow field in the interblade region. The data acquisition package collects all the data available while the machine is running and sorts the raw data into bins corresponding to the various circumferential positions. Each velocity measurement — all three components — along with the circumferential position information is collected by a DEC PDP 11/23 Computer. The analysis package allows the user to examine a portion of the interblade region, look at alternate interblade gaps, omit data during blade passage, etc.
Statistical properties such as mean, turbulence, skewness, flatness, Reynolds stress values, and projections in cross sectional planes are obtained and displayed as a function of circumferential position. Thus, the detailed properties of the three dimensional flow field are obtained from the three component LDV measurements.
An Effective System for Sealing Toxic Gases in Centrifugal Compressors
Authors: Ronsky N. Daryl , Conquergood C. Peter , Harris Tim , Davies Islwyn 
Published: March 2015

Maintaining seal oil systems has traditionally been one of the biggest problems faced by operators of centrifugal compression equipment. This problem is compounded when highly toxic gases are being compressed. This paper describes the retrofit of a simple, effective, mechanical dry seal system which eliminated one sour gas operator’s problems. The retrofit resulted in a safe, easy-to-operate system, which vents no toxic gases into the environment.
The retrofit was completed on a gas gathering compressor operating with hydrogen sulphide at a discharge pressure of 10,000 kPa (1500 psig), a discharge temperature of 150° C (300° F) and an operating speed of 23 500 rpm.
This paper describes the operating problems encountered with the traditional seal oil system, the successful resolution of the problems with the mechanical dry seal system and operational data of the successful retrofit.
Coping With Gas Turbine Emissions Regulations
Authors: Solt J. C. 
Published: March 2015

The subject of emissions regulations is complex. Worldwide there are over 20 countries that regulate permissible emissions, each with its own regulations. Certain groups, such as the European Economic Community (EEC) have regulations for all of their members. In the United States, federal regulations (Fig. 1) fall under the Environmental Protection Agency (EPA), while there are separate regulations for each of the 50 states. Fortunately, most of the state regulations are simply adapted from and are quite similar to federal regulations. However, several states have significantly more stringent standards than the federal regulations. The State of California, for example, not only has separate regulations, but each of the 45 pollution control districts within the state has its own regulations, most of which differ substantially from each other.
The following is a discussion of the U.S. federal regulations as they apply to areas that presently meet the ambient air quality standards. These are called attainment areas. Areas that do not meet the ambient air quality standards are called nonattainment areas. For a gas turbine application in a nonattainment area, such as Denver, or in the State of California, it is imperative to check local regulations, which result from the federal regulations for nonattainment areas.
The Replacement Cruise Engine for the DDH 280 Tribal Class Destroyer
Authors: Mack I. D. , Hurl D. J. 
Published: March 2015

A description of the existing propulsion plant in the DDH 280 Class Destroyer and problems with the existing cruise engine fit are outlined. The trade off analysis and option study which led to the decision to replace the existing cruise engine with a replacement gas turbine is examined and the criteria which were used in the selection of the Allison 570 K are then briefly addressed. Finally the intended technical fit and design considerations associated with the installation into the vessel are described.
The opinions expressed herein are those of the authors and not necessarily of the Department of National Defence, Canada.
LM500 CODAG Propulsion for the Danish Navy Stanflex 300
Authors: Daley Leonard T. , Munk Torben 
Published: March 2015

A description of the Royal Danish Navy’s answer to fleet modernization — a standard hull platform with multi-mission interchangeable modules designed to replace obsolescent classes of minelayer, mine sweeper, surveillance and missile attack craft.
Propulsion for this ship will be provided by a triple screw combined diesel and gas turbine (CODAG) plant comprised of a General Electric Co. (USA) type LM500 marinized aeroderivative gas turbine and two (2) Motoren und Turbinen Union (MTU) 16V396 TB84 diesels. This is the first naval application of the General Electric Co. (USA) LM500 gas turbine.
Altitude Tests of the XF3-30 Turbofan
Authors: Kitamura Masayuki , Uchida Morimasa , Yashima Satoshi 
Published: March 2015

The XF3-30 turbofan has been successfully developed as the propulsion system for the Japan Air Self Defence Force’s XT-4 military intermediate trainer. Altitude tests were conducted four times in ATF (AEDC and GE) and four times on FTB in the engine development program.
Utilizing the results of each test, the engine has been improved in sufficient time to meet the aircraft development program schedule, and successful flight tests of XT-4 powered by XF3-30 have been made.
The Circumferential Velocity Profile for Secondary Flow Calculations
Authors: Douvikas D. , Kaldellis J. , Papailiou K. D. 
Published: March 2015

The circumferential (and transverse) velocity profile is examined in external and internal flow problems. The various cases, unbounded, semi-bounded and fully bounded, are examined and expressions are developed for each one of them, taking viscous and compressibility effects into account.
A comprehensive and generalised description is presented which considers the transfer of vorticity along the streamlines and provides simple expressions for the circumferential velocity profiles which, although different from previous attempts, have as particular cases the results of Johnston’s and Hawthorne’s work.
Performance of the Integrated Gas and Steam Cycle (IGSC) for Reheat Gas Turbines
Authors: Takeya Kazuo , Yasui Hajime 
Published: March 2015

In 1978, the Japanese government started a national project for energy conservation called the Moonlight Project. The Engineering Research Association for Advanced Gas Turbines was selected to research and develop an advanced gas turbine for this project.
The development stages were planned as follows: First, the development of a reheat gas turbine for a pilot plant (AGTJ-100A), and second, a prototype plant (AGTJ-100B). The AGTJ-100A has been undergoing performance tests since 1984 at the Sodegaura Power Station of the Tokyo Electric Power Co., Inc. (TEPCO).
The inlet gas temperature of the high pressure turbine (HPT) of the AGTJ-100A is 1573K, while that of the AGTJ-100B is 100K higher. Therefore, various advanced technologies have to be applied to the AGTJ-100B HPT. Ceramic coating on the HPT blades is the most desirable of these technologies.
In this paper, the present situation of development, as well as future R & D plans for ceramic coating, is taken into consideration. Steam blade cooling is applied for the IGSC.
Applying Kalina Technology to a Bottoming Cycle for Utility Combined Cycles
Authors: Kalina A. L. , Leibowitz H. M. 
Published: March 2015

A new power generation technology often referred to as the Kalina cycle, is being developed as a direct replacement for the Rankine steam cycle. It may be applied to any thermal heat source, low or high temperature. Among several Kalina cycle variations there is one that is particularly well suited as a bottoming cycle for utility combined cycle applications. It is the subject of this paper.
Using an ammonia/water mixture as the working fluid and a condensing system based on absorption refrigeration principles the Kalina bottoming cycle outperforms a triple pressure steam cycle by 16 percent. Additionally, this version of the Kalina cycle is characterized by an intercooling feature between turbine stages, diametrically opposite to normal reheating practice in steam plants.
Energy and mass balances are presented for a 200 MWe Kalina bottoming cycle. Kalina cycle performance is compared to a triple pressure steam plant. At a peak cycle temperature of 950° F the Kalina plant produces 223.5 MW vs. 192.6 MW for the triple pressure steam plant, an improvement of 16.0 percent. Reducing the economizer pinch point to 15° F results in a performance improvement in excess of 30 percent.
Development and Testing of the 13MW Class Heavy Duty Gas Turbine MF-111
Authors: Akita Eiji , Aoyama Kuniaki , Tsukuda Yoshiaki , Fukue Ichiro , Aoki Sunao 
Published: March 2015

A new 13 MW class heavy duty gas turbine “MF-111” with the combustor outlet temperature of 1250°C (1523 K) was developed and tested.
The thermal efficiency of MF-111 is designed to be 32% for simple-cycle and 45% in combined-cycle operation.
MF-111 has single-shaft configuration, 15-stage axial flow compressor, 8 cannular type combustors and 3-stage axial flow turbine.
Advanced cooling technology was incorporated for the turbine and the combustor design to be capable of higher combustor outlet temperature.
The prototype was shoptested at full load in April, 1986. The performance and the metal temperatures of hot parts were confirmed to well satisfy the design goal. The first machine of MF-111 started the commercial operation from August, 1986 and has logged satisfactory operations.
Compressor Turbine Vane Ring (PT6 Engine) Repair Development
Authors: Sourial N. 
Published: March 2015

In today’s aerospace industry there is a trend, which was probably started by economic factors, to donate more time and effort establishing viable salvage repairs of high priced items. This not only creates a competitive edge for the individual who initiates the repair but also stimulates industry to utilize other conceptions or improvements of existing techniques.
This paper will deal with one such item which for some years was considered “unrepairable” due to the complexity of its design.
The compressor turbine vane ring in the PT6 Engine was selected because it is located in the heart of the engine. It is subjected to a very severe environment and damages occuring to it are a common problem in all gas turbine engines. Consequently this repair, which brings the part back to its new condition for a fraction of the replacement cost, involves a great deal of state of the art technology.
Degradation of MCrA1Y Coatings by Interdiffusion
Authors: Mazars P. , Manesse D. , Lopvet C. 
Published: March 2015

Coatings such as NiCrA1Y, CoCrA1Y and FeCrA1Y are deposited by plasma spraying under partial pressure on commercial f.c.c. alloys of nickel, cobalt, and iron. The interdiffusion between coating and substrate is limited in the cases of NiCrA1Y/Ni base and CoCrA1Y/Co base. On the other hand, rapid diffusion of the aluminium into the substrate occurs in the system FeCrA1Y/Fe base.
When mixed systems MCrA1Y/M’ base are studied, an interdiffusion is usually observed between the elements M and M’ except in the case of the systems NiCrA1Y/Co base and FeCrA1Y/Co base where carbide diffusion barriers are formed.
The HF “Fluoride-Ion” Cleaning Technique for Superalloys
Authors: Pochet Louis F. , Clavel Alfred L. 
Published: March 2015

Fluoride-ion cleaning, using Hydrogen Fluoride gas as the active agent, is rapidly becoming established as a cost effective method to prepare nickel and cobalt based superalloys for braze repair.
Background and comparative information on the four basic processes currently in use are discussed. The latest process using hydrogen fluoride gas directly is described in detail including the methods used for precise process control and safe handling of the HF input gas, as well as the off-gas fluoride compounds. Alloys successfully prepared for braze repair are listed. Other uses for the process and potential uses for the manufacture of new components are suggested.
Low Frequency Noise Emission From a Natural Gas Compressor Station
Authors: Sieminski Manfred , Schneider Manfred 
Published: March 2015

Low Frequency Noise at Gas Turbines
A natural gas compressor station that was equipped with Hispano Suiza Turbines THM 1202 emitted high intensity noise between 20 Hz and 40 Hz, causing window vibrations and standing waves within the living rooms of a nearby residential area.
Since additional sound attenuation by increasing the volume of the exhaust silencers was impossible, further investigations were carried out to explain the mechanism of this low frequency noise emission. By changing the flame pattern inside the combustion chambers of the turbines it was possible to achieve a remarkable reduction at 31.5 Hz amounting to 15 dB. The investigation procedure leading to the final results will be the subject of this presentation.
Prediction of NO and CO Distribution in Gas Turbine Combustors
Authors: Kajita Shinichi , Matumoto Ryuichi 
Published: March 2015

An experimental and numerical investigation was conducted to assess the validity of a prediction procedure of NO and CO formed in gas turbine combustors.
A premixed gas turbine combustor burning propane was used in the experimental program, and the flow, temperature and pollutants fields were measured.
The prediction procedure solves the governing conservation equations of mass, momentum, energy and chemical species simultaneously by means of finite difference solution algorithm. Two main mathematical models were employed in the procedure to represent the turbulent nature of the flow and the chemical reaction rates. For the turbulence model, the two-equation k-ε model was applied. The chemical reaction model assumed a two step reaction, and the effect of turbulence on reaction rates is taken into account by employing the modified eddy-break-up model which considers the dissipation rate of eddy and the concentrations of fuel and combustion products. The reaction rate is considered to be the smaller of the two expressions given by the Arrhenius equation and the modified eddy-break-up model. For NO formation, the extended Zeldovich mecanism was assumed. The prediction results were compared with those obtained from the corresponding expreiment.
The prediction results showed the correct overall features, but a quantitative agreement was not obtained for NO and CO concentrations.
Development of Dry Two-Stage Low-NOx Combustor for a Gas Turbine
Authors: Kuroda M. , Ishibashi Y. , Iizuka N. , Uchiyama Y. , Sato I. , Wada K. , Tokunaga K. , Hata T. 
Published: March 2015

A dry two-stage low NOx combustor for a 73 MW gas turbine has been developed to meet stringent NOx limitations in Japan. This combustion system has a fuel-air control mechanism to ensure stable switching from one-stage combustion to two-stage combustion.
NOx emission is very low not only at full load but also in the entire gas turbine operating range.
The NOx characteristics have proved to be within the goal in full scale, full pressure combusion tests.
This paper outlines the development plan and describes the structure and combustion characteristics of the low NOx combustor.
Three-Dimensional Calculation of Wall Boundary Layer Flows in Turbomachines
Authors: Lindsay W. L. , Carrick H. B. , Horlock J. H. 
Published: March 2015

An integral method of calculating the three-dimensional turbulent boundary layer development through the blade rows of turbomachines is described. It is based on the solution of simultaneous equations for
(i) & (ii) the growth of streamwise and cross-flow momentum thicknesses;
(iii) entrainment;
(iv) the wall shear stress;
(v) the position of maximum cross-flow.
The velocity profile of the streamwise boundary layer is assumed to be that described by Coles. The cross-flow profile is assumed to be the simple form suggested by Johnston, but modified by the effect of bounding blade surfaces, which restrict the cross-flow. The momentum equations include expressions for “force-defect” terms which are also based on secondary flow analysis.
Calculations of the flow through a set of guide vanes of low deflection show good agreement with experimental results; however, attempts to calculate flows of higher deflection are found to be less successful.
Electronic Trend Monitoring and Exceedance Recording Systems: A Means to Improved Turbine Engine Reliability
Authors: Moore Michael G. 
Published: March 2015

Current technology has yielded engine mountable, compact microprocessor-based recording systems that can record information that will aid in maintenance planning and, thus, yield improved reliability. Among data available are:
1) Trend Recording - revealing deviations from non indicating engine performance deterioration
2) Exceedance Recording - documenting time, date, duration, and severity of exceedances for parameters such as temperature, torque, N1, N2, etc.
3) Power Ratings - power (“hit”) checks are available instantaneously and through the through the exercise of power cycle, go or no-go determination made through real time analysis of current sensor outputs against defined tolerances adjusted to density altitude.
4) Run Data - total time duration within each scale of the operating range for each engine and airframe parameter
5) Cycle Counts - start, power, life fatigue, creep life, and improper cool down cycles are tracked based upon engine manufacturer formulae
These engine recorders primarily utilize the existing engine sensors with no effect on signals to established instrument.
Current technology allows these engine recorders to be universal to many different engines, with limit thresholds entered at the factory through a computer keyboard.
Automatic learning‐based beam angle selection for thoracic IMRT
Authors: Amit Guy , Purdie Thomas G. , Levinshtein Alex , Hope Andrew J. , Lindsay Patricia , Marshall Andrea , Jaffray David A. , Pekar Vladimir 
Published: March 2015

Purpose:The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner's clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload.Methods:The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth.Results:The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume coverage and organ at risk sparing and were superior over plans produced with fixed sets of common beam angles. The great majority of the automatic plans (93%) were approved as clinically acceptable by three radiation therapy specialists.Conclusions:The results demonstrated the feasibility of utilizing a learning‐based approach for automatic selection of beam angles in thoracic IMRT planning. The proposed method may assist in reducing the manual planning workload, while sustaining plan quality.
Feasibility and robustness of dose painting by numbers in proton therapy with contour‐driven plan optimization
Authors: Barragán A. M. , Differding S. , Janssens G. , Lee J. A. , Sterpin E. 
Published: March 2015

Purpose:To prove the ability of protons to reproduce a dose gradient that matches a dose painting by numbers (DPBN) prescription in the presence of setup and range errors, by using contours and structure‐based optimization in a commercial treatment planning system.Methods:For two patients with head and neck cancer, voxel‐by‐voxel prescription to the target volume (GTVPET) was calculated from 18FDG‐PET images and approximated with several discrete prescription subcontours. Treatments were planned with proton pencil beam scanning. In order to determine the optimal plan parameters to approach the DPBN prescription, the effects of the scanning pattern, number of fields, number of subcontours, and use of range shifter were separately tested on each patient. Different constant scanning grids (i.e., spot spacing = Δx = Δy = 3.5, 4, and 5 mm) and uniform energy layer separation [4 and 5 mm WED (water equivalent distance)] were analyzed versus a dynamic and automatic selection of the spots grid. The number of subcontours was increased from 3 to 11 while the number of beams was set to 3, 5, or 7. Conventional PTV‐based and robust clinical target volumes (CTV)‐based optimization strategies were considered and their robustness against range and setup errors assessed. Because of the nonuniform prescription, ensuring robustness for coverage of GTVPET inevitably leads to overdosing, which was compared for both optimization schemes.Results:The optimal number of subcontours ranged from 5 to 7 for both patients. All considered scanning grids achieved accurate dose painting (1% average difference between the prescribed and planned doses). PTV‐based plans led to nonrobust target coverage while robust‐optimized plans improved it considerably (differences between worst‐case CTV dose and the clinical constraint was up to 3 Gy for PTV‐based plans and did not exceed 1 Gy for robust CTV‐based plans). Also, only 15% of the points in the GTVPET (worst case) were above 5% of DPBN prescription for robust‐optimized plans, while they were more than 50% for PTV plans. Low dose to organs at risk (OARs) could be achieved for both PTV and robust‐optimized plans.Conclusions:DPBN in proton therapy is feasible with the use of a sufficient number subcontours, automatically generated scanning patterns, and no more than three beams are needed. Robust optimization ensured the required target coverage and minimal overdosing, while PTV‐approach led to nonrobust plans with excessive overdose. Low dose to OARs can be achieved even in the presence of a high‐dose escalation as in DPBN.