DOCSLIB.ORG

Axial Compressor Stall and Surge Prediction by Measurements

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Axial Compressor Stall and Surge Prediction by Measurements International Journal of Rotating Machinery (C) 1999 OPA (Overseas Publishers Association) N.V. 1999, Vol. 5, No. 2, pp. 77-87 Published by license under Reprints available directly from the publisher the Gordon and Breach Science Photocopying permitted by license only Publishers imprint. Printed in Malaysia. Axial Compressor Stall and Surge Prediction by Measurements H. HONEN * Institut jFtr Strahlantriebe und Turboarbeitsmaschinen, RWTH Aachen /Aachen University of Technology), 52062 Aachen, Germany (Received 3 April 1997;In final form 10 July 1997) The paper deals with experimental investigations and analyses of unsteady pressure dis- tributions in different axial compressors. Based on measurements in a single stage research compressor the influence of increasing aerodynamic load onto the pressure and velocity fluctuations is demonstrated. Detailed measurements in a 14-stage and a 17-stage gas turbine compressor are reported. For both compressors parameters could be found which are clearly influenced by the aerodynamic load. For the 14-stage compressor the principles for the monitoring of aerodynamic load and stall are reported. Results derived from a monitoring system for multi stage compressors based on these principles are demonstrated. For the 17-stage compressor the data enhance- ment of the measuring signals is shown. The parameters derived from these results provide a good base for the development of another prediction method for the compressor stability limit. In order design an on-line system the classification of the operating and load conditions is provided by a neural net. The training results of the net show a good agreement with different experiments. Keywords." Stall and surge monitoring, Unsteady pressure measurements, Compressor load analysis, Load parameters, Neural nets 1. INTRODUCTION high level. This aim only can be reached by an in- creasing observation and monitoring of the opera- The requirement ofhigh economy of turbomachines tional conditions inside the machine. causes higher efficiencies and power densities with Various efforts have been made to find measuring increasing profile and assembly loads. On the other and analysis methods for the detection of the hand the loads are limited by the requirement of stability limit of compressors (Ludwig and Nenni, operational safety of the machine. Therefore, the 1979; Paduano et al., 1991; Wang et al., 1993). For main aim is the guaranty of the availability on a save compressor operation it is necessary to know Fax: 0241-8888-229. 77 78 H. HONEN the distance of the momentary operation point is detected. Figure demonstrates these effects for from this limit. Therefore, the detection of the two different operating points of the stage. The occurrence of stall is not the only aim of all these radial turbulence distributions for the axial gaps struggles. Moreover, an indicator for the approxi- between the bladings visualize the influence of the mation to the stability limit has to be found. Several aerodynamic load onto the flow in the entire stage. investigations are looking for so called stall pre- Due to the increasing aerodynamic load a corner cursors which can be harmonic waves superposed stall region with fluctuating boundaries occurs in to the flow or other fluctuations which induce the the stator. With higher loads this seperation zone beginning of stall (Inoue et al., 1990; Garnier et al., grows in to the blade passage. Glue on hot film 1990). sensors on the stator vanes provided information Due to the progress in computer development it about the behavior of the unsteady flow. Thus, the is more and more possible to pick up and handle a extend of the corner stall region inside the stator high number of measuring data on-line. Even could be observed. One major result of these inves- unsteady effects can be observed in real time. Thus, tigations was the experience that only sensors out- the on-line calculation and observation of char- side of the separation region were able to measure acteristic values becomes realistic. The combina- periodic fluctuations due to the rotor/stator inter- tion of a suitable definition of detection and action. Measuring sensors positioned inside this observation parameters based on measuring results separation zone can only detect high turbulent together with the corresponding analysis algorithms fluctuations. All periodic information damped enables the operator to run a compressor close to down and does not reach the sensors. the stability limit at high efficiencies. Measurements in a 14-stage gas turbine com- pressor provided detailed information about the unsteady flow behavior in a multi stage compressor 2. EXPERIMENTAL INVESTIGATIONS influenced by different compressor loads. For a long term investigation the stages 11 and 13 were Measurements in three different axial compres- equipped with wall mounted piezo-electric pressure sors show the influence of the aerodynamic load sensors in the axial gaps between rotor and stator. onto the patterns of unsteady flow distributions. The measurements were carried out for a period of Experimental investigations of the unsteady three about four months during industrial operation dimensional flow inside a single stage research under full load conditions of the gas turbine. compressor provided a basis for the understanding During these measurements a failure in the gas of the unsteady effects in separation zones (Gallus turbine control system occurred and the operating and H6nen, 1986). Furthermore, these measuring point of the compressor drifted very slowly towards results visualized the influence of separated flow the stability limit. Finally the surge control of the regions onto the signal form and behavior of wall gas turbine provoked a shut down. mounted dynamic sensors as well as probes. During this time period the pressure sensors The aerodynamic load of the compressor was registered the same effect as demonstrated in the increased up to the stability limit. Measurements single stage compressor. At a certain load level in with hot wire probes in the axial gap between rotor the 13th stage the periodic information disap- and stator demonstrated the changes of the peared. This indicates that here a separation region unsteady flow patterns downstream the rotor. occurred which covered the measuring sensor. In Depending on the higher load the profile boundary order to be able to handle the great number of data layers become thicker which can be detected in from the long term investigation a data reduction wider blade wakes. In addition the stochastic fluc- by FFT analysis was carried out (Fig. 2). About tuations are elevated and a higher turbulence level half an hour before the automatic shut down the AXIAL COMPRESSOR STALL, SURGE PREDICTION 79 Tu 10 IGV rtip Rotor Stator rhub FIGURE Turbulence distribution in the axial gaps of a single stage research center. frequency spectra of the 13th stage only showed covers the wall mounted pressure sensor and high noise levels, whereas in the lth stage the damps down the periodic information coming to characteristic peak was increased caused by the measuring position. growing blade wakes due to the higher aerody- Another investigation was carried out in an namic load (H6nen and Gallus, 1995). industrial gas turbine. On a test field detailed The growing profile boundary layers in the rotor measurements were taken in the 17-stage axial com- are centrifugated to the casing where side wall pressor. The first two stages were equipped with five boundary layer thickness itself is also increased. wall mounted dynamic pressure sensors in the cas- This causes an accumulation of low energy ing over the rotors at several axial positions. In five material behind the rotor. The high back pressure test runs at part load with different operating con- at the compressor outlet disables the exit flow so ditions (Table I) the rotor speed of the machine was that a casing stall occurs. This separated region reduced until the stability limit of the compressor 80 H. HONEN lh sage f(8) t j t 1(9,10) (Y1 13th stage o.o lkl 29001).0 O.n (Hx) 20000.0 FIGURE 2 Comparison of the frequency patterns in the lth and 13th stage for two operating points (left side: normal operation, right side: stall operation). TABLE Comparison of the operation parameters for different test runs Test run VSV position Bleed door #1 Bleed door #2 Bleed door #3 20 Closed Closed Closed 2 0 Open Closed Closed 3 0 Closed Closed Closed 4 20 Closed Closed Closed 5 20 Open Open Closed was reached. The pressure signals were recorded in the static pressure is elevated up to a maximum. real time to a magnetic tape recorder and analyzed Just after the passing of the rotor blade a sharp after the experiments. decrease is observed due to the lower pressure at As an example the time averaged signals of the the suction side of the profile. The last measuring first test run are shown in Fig. 3 for the first position is located in the axial gap between rotor measuring position in stage 1. The patterns of the and stator. Here the flow is influenced by the blade first four pressure transducers show the wall wakes downstream of the rotor. pressure distribution above the passing rotor It becomes obvious that the signal patterns channels for the different sensor positions. From strongly depend on the measuring position. In the the suction side to the pressure side of the channels front part of the blading the signal forms are AXIAL COMPRESSOR STALL, SURGE PREDICTION 30O0 position 4 2000 position 1 1 000 3000 position 2 position 5 20O0 1 000 3OOO 2000 p 3 1 000 ..osition FIGURE 3 Time average pressure signals at the measuring positions over rotor 1. influenced by many different flow effects. In the conditions and the last one shows the conditions last third, especially at measuring position 4 a low about 50 revolutions before the beginning of surge.
Load more

Recommended publications
  • Stall/Surge Dynamics of a Multi-Stage Air Compressor in Response to a Load Transient of a Hybrid Solid Oxide Fuel Cell-Gas Turbine System
    Journal of Power Sources 365 (2017) 408e418 Contents lists available at ScienceDirect Journal of Power Sources journal homepage: www.elsevier.com/locate/jpowsour Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system * Mohammad Ali Azizi, Jacob Brouwer Advanced Power and Energy Program, University of California, Irvine, USA highlights Dynamic operation of a hybrid solid oxide fuel cell gas turbine system was explored. Computational fluid dynamic simulations of a multi-stage compressor were accomplished. Stall/surge dynamics in response to a pressure perturbation were evaluated. The multi-stage radial compressor was found robust to the pressure dynamics studied. Air flow was maintained positive without entering into severe deep surge conditions. article info abstract Article history: A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and Received 14 August 2017 control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW Accepted 4 September 2017 hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to Keywords: simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW Solid oxide fuel cell system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial Hybrid fuel cell gas turbine Dynamic simulation compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design.
    [Show full text]
  • 2.0 Axial-Flow Compressors 2.0-1 Introduction the Compressors in Most Gas Turbine Applications, Especially Units Over 5MW, Use Axial fl Ow Compressors
    2.0 Axial-Flow Compressors 2.0-1 Introduction The compressors in most gas turbine applications, especially units over 5MW, use axial fl ow compressors. An axial fl ow compressor is one in which the fl ow enters the compressor in an axial direction (parallel with the axis of rotation), and exits from the gas turbine, also in an axial direction. The axial-fl ow compressor compresses its working fl uid by fi rst accelerating the fl uid and then diffusing it to obtain a pressure increase. The fl uid is accelerated by a row of rotating airfoils (blades) called the rotor, and then diffused in a row of stationary blades (the stator). The diffusion in the stator converts the velocity increase gained in the rotor to a pressure increase. A compressor consists of several stages: 1) A combination of a rotor followed by a stator make-up a stage in a compressor; 2) An additional row of stationary blades are frequently used at the compressor inlet and are known as Inlet Guide Vanes (IGV) to ensue that air enters the fi rst-stage rotors at the desired fl ow angle, these vanes are also pitch variable thus can be adjusted to the varying fl ow requirements of the engine; and 3) In addition to the stators, another diffuser at the exit of the compressor consisting of another set of vanes further diffuses the fl uid and controls its velocity entering the combustors and is often known as the Exit Guide Vanes (EGV). In an axial fl ow compressor, air passes from one stage to the next, each stage raising the pressure slightly.
    [Show full text]
  • Turbofan Engine Malfunction Recognition and Response Final Report
    07/17/09 Turbofan Engine Malfunction Recognition and Response Final Report Foreword This document summarizes the work done to develop generic text and video training material on the recognition and appropriate response to turbofan engine malfunctions, and to develop a simulator upgrade package improving the realism of engine malfunction simulation. This work was undertaken as a follow-on to the AIA/AECMA report on Propulsion System Malfunction Plus Inappropriate Crew Response (PSM+ICR), published in 1998, and implements some of the recommendations made in the PSM+ICR report. The material developed is closely based upon the PSM+ICR recommendations. The work was sponsored and co-chaired by the ATA and FAA. The organizations involved in preparation and review of the material included regulatory authorities, accident investigation authorities, pilot associations, airline associations, airline operators, training companies and airplane and engine manufacturers. The FAA is publishing the text and video material, and will make the simulator upgrade package available to interested parties. Reproduction and adaptation of the text and video material to meet the needs of individual operators is anticipated and encouraged. Copies may be obtained by contacting: FAA Engine & Propeller Directorate ANE-110 12 New England Executive Park Burlington, MA 01803 1 07/17/09 Contributing Organizations and Individuals Note: in order to expedite progress and maximize the participation of US airlines, it was decided to hold all meetings in North America. European regulators, manufacturers and operators were both invited to attend and informed of the progress of the work. Air Canada Capt. E Jokinen ATA Jim Mckie AirTran Capt. Robert Stienke Boeing Commercial Aircraft Van Winters CAE/ Flight Safety Boeing Capt.
    [Show full text]
  • A Study on the Stall Detection of an Axial Compressor Through Pressure Analysis
    applied sciences Article A Study on the Stall Detection of an Axial Compressor through Pressure Analysis Haoying Chen 1,† ID , Fengyong Sun 2,†, Haibo Zhang 2,* and Wei Luo 1,† 1 Jiangsu Province Key Laboratory of Aerospace Power System, College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao Street, Nanjing 210016, China; [email protected] (H.C.); [email protected] (W.L.) 2 AVIC Aero-engine Control System Institute, No. 792 Liangxi Road, Wuxi 214000, China; [email protected] * Correspondence: [email protected] † These authors contributed equally to this work. Received: 5 June 2017; Accepted: 22 July 2017; Published: 28 July 2017 Abstract: In order to research the inherent working laws of compressors nearing stall state, a series of compressor experiments are conducted. With the help of fast Fourier transform, the amplitude–frequency characteristics of pressures at the compressor inlet, outlet and blade tip region outlet are analyzed. Meanwhile, devices imitating inlet distortion were applied in the compressor inlet distortion disturbance. The experimental results indicated that compressor blade tip region pressure showed a better performance than the compressor’s inlet and outlet pressures in regards to describing compressor characteristics. What’s more, compressor inlet distortion always disturbed the compressor pressure characteristics. Whether with inlet distortion or not, the pressure characteristics of pressure periodicity and amplitude frequency could always be maintained in compressor blade tip pressure. For the sake of compressor real-time stall detection application, a compressor stall detection algorithm is proposed to calculate the compressor pressure correlation coefficient. The algorithm also showed a good monotonicity in describing the relationship between the compressor surge margin and the pressure correlation coefficient.
    [Show full text]
  • The Power for Flight: NASA's Contributions To
    The Power Power The forFlight NASA’s Contributions to Aircraft Propulsion for for Flight Jeremy R. Kinney ThePower for NASA’s Contributions to Aircraft Propulsion Flight Jeremy R. Kinney Library of Congress Cataloging-in-Publication Data Names: Kinney, Jeremy R., author. Title: The power for flight : NASA’s contributions to aircraft propulsion / Jeremy R. Kinney. Description: Washington, DC : National Aeronautics and Space Administration, [2017] | Includes bibliographical references and index. Identifiers: LCCN 2017027182 (print) | LCCN 2017028761 (ebook) | ISBN 9781626830387 (Epub) | ISBN 9781626830370 (hardcover) ) | ISBN 9781626830394 (softcover) Subjects: LCSH: United States. National Aeronautics and Space Administration– Research–History. | Airplanes–Jet propulsion–Research–United States– History. | Airplanes–Motors–Research–United States–History. Classification: LCC TL521.312 (ebook) | LCC TL521.312 .K47 2017 (print) | DDC 629.134/35072073–dc23 LC record available at https://lccn.loc.gov/2017027182 Copyright © 2017 by the National Aeronautics and Space Administration. The opinions expressed in this volume are those of the authors and do not necessarily reflect the official positions of the United States Government or of the National Aeronautics and Space Administration. This publication is available as a free download at http://www.nasa.gov/ebooks National Aeronautics and Space Administration Washington, DC Table of Contents Dedication v Acknowledgments vi Foreword vii Chapter 1: The NACA and Aircraft Propulsion, 1915–1958.................................1 Chapter 2: NASA Gets to Work, 1958–1975 ..................................................... 49 Chapter 3: The Shift Toward Commercial Aviation, 1966–1975 ...................... 73 Chapter 4: The Quest for Propulsive Efficiency, 1976–1989 ......................... 103 Chapter 5: Propulsion Control Enters the Computer Era, 1976–1998 ........... 139 Chapter 6: Transiting to a New Century, 1990–2008 ....................................
    [Show full text]
  • Nasa Tm X-71633 Prediction of Compressor Stall For
    NASA TECHN ICAL NASA TM X-71633 MEMORANDUM C,- PREDICTION OF COMPRESSOR STALL FOR DISTORTED AND UNDISTORTED FLOW BY USE OF A MULTISTAGE COMPRESSOR SIMULATION ON THE DIGITAL COMPUTER by Carl Jo Daniele and Fred Teren Lewis Research Center Cleveland, Ohio 44135 TECHNICAL PAPER to be presented at Thirteenth Aerospace Sciences Meeting sponsored by American Institute of Aeronautics and Astronautics Pasadena, California, January 20-22, 1975 (NASA-TM-X-71633) PREDICTION OF N75- 13190 COMPRESSOR STALL FOR DISTORTED AND UNDISTORTED FLOW BY USE OF A MULTISTAGE COMPRESSOR SIMULATION ON THE DIGITAL Unclas COMPUTER (NASA) 12 p HC $3.25 CSCL 20D G3/34 03669 PREDICTION OF COMPRESSOR STALL FOR DISTORTED AND UNDISTORTED FLOW BY USE OF A MULTISTAGE COMPRESSOR SIMULATION ON THE DIGITAL COMPUTER Carl J. Daniele and Fred Teren National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio Abstract 6 ratio of total pressure to sea level pressure A simulation technique is presented for the prediction of compressor stall for axial-flow com- a ratio of total temperature to sea level pressors for clean and distorted inlet flow. The temperature simulation is implemented on the digital computer and uses stage stacking and lumped-volume gas dy- p weight density, kg/m 3 ; ibm/ft 3 namics. The resulting nonlinear differential equations are linearized about a steady-state op- O flow coefficient erating point, and a Routh-Hurwitz stability test is performed on the linear system matrix. Par- pressure coefficient S allel compressor theory is utilized to extend the 0 technique to the distorted inlet flow problem. T temperature coefficient L The method is applied to the eight-stage J85-13 compressor.
    [Show full text]
  • Accident Prevention December 1993
    F L I G H T S A F E T Y F O U N D A T I O N Accident Prevention Vol. 50 No. 12 For Everyone Concerned with the Safety of Flight December 1993 Training, Deicing and Emergency Checklist Linked in MD-81 Accident Following Clear-ice Ingestion by Engines While the crew of a Scandinavian Airlines System (SAS) jet transport was praised for its skill in executing an off-airport landing in an aircraft without operating engines, Swedish accident investigators found serious deficiencies in aircraft ground deicing procedures and no awareness of a throttle system that contributed to the severity of engine surges that destroyed both engines. Editorial Staff Report The crash of a Scandinavian Airlines System (SAS) McDonnell While the aircraft was being deiced on the ground, the Douglas DC-9-81 (MD-81) after clear ice was ingested by captain mentioned the procedure to follow in the event of the engines raises serious issues about training, quality an engine failure at Stockholm, saying (of the procedure), control and flight operations, an official Swedish aircraft “Engine failure follow … standard instrument departure accident investigation said. [SID] ... 2,000 ... that’s very general.” The aircraft’s right engine began to surge shortly after The aircraft took off at 0847 hours local time, the report takeoff from Stockholm/Arlanda Airport on Dec. 27, 1991, said. Sunrise was at 0848. Weather was reported at 0850 as according to a recent report by the Swedish Board of wind 360 degrees at 11 knots, visibility 6.2 miles (10 Accident Investigation (BAI).
    [Show full text]
  • Reduction of Stall in Axial Flow Compressor
    Special Issue - 2015 International Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 NCRAIME-2015 Conference Proceedings Reduction of Stall in Axial Flow Compressor Mr.A.Sabik Nainar M.E., Mr.A.Karthikeyan .M.E Department of Aeronautical Engineering Department of Aeronautical Engineering Excel Engineering College Excel Engineering College Namakkal, India Namakkal, India I. Kalimuthu Kumar S.Mohamed Ashk Ali Department of Aeronautical Engineering Department of Aeronautical Engineering Excel Engineering College Excel Engineering College Namakkal, India Namakkal, India N.Soundarrajan Department of Aeronautical Engineering Excel Engineering College Namakkal, India Abstract:-Aircraft axial flow compressors have been an flow pattern obtained to the compressor at various angle of important subject to study as the blades of compressor attack. The reduction of stall and surge is estimated by encounter stalling and other off design performances during various methodologies some of them flow analysis and the various angles of attack of an aircraft. The objectives are to design calculation. In these project is used to analyses the suppress rotating stall and surge further to extend stable flow properties of inlet guide vanes and improve the engine operating range of the compressor system. Using moveable performance also. inlet guide vanes, the uniform flow into compressor inlet can be achieved and thereby to improve stability and fuel 1.2 Need and scope efficiency. The improper airflow creates stalling, surging and chocking. This project is to study the effect of angle of attack The stability analysis and estimation of axial flow on inlet guide vanes and analysed with both experimentally compressor is very much important for each and every and using software.
    [Show full text]
  • Acceleration Control for a Gas Turbine Engine with Duct Pressure Loss Compensation
    Europaisches Patentamt European Patent Office © Publication number: 0 401 152 A2 Office europeen des brevets © EUROPEAN PATENT APPLICATION © Application number: 90630111.4 © Int. CIA F02C 9/28, F04D 27/02 © Date of filing: 30.05.90 © Priority: 30.05.89 US 359186 © Applicant: UNITED TECHNOLOGIES 30.05.89 US 359451 CORPORATION United Technologies Building 1, Financial @ Date of publication of application: Plaza 05.12.90 Bulletin 90/49 Hartford, CT 061 01 (US) © Designated Contracting States: © Inventor: Smith, Jesse Walter DE FR GB IT 4186 S.E. Fairway Court Stuart, Florida 34997(US) © Representative: Waxweiier, Jean et al OFFICE DENNEMEYER S.a.r.l. P.O. Box 1502 L-1015 Luxembourg(LU) © Acceleration control for a gas turbine engine with duct pressure loss compensation. © A control to control the acceleration mode for a gas turbine engine so as to allow the engine to accelerate rapidly with adequate stall margin by sim- ulating a compressor stall limit. The stall limit is attained by generating a limiting ratio of burner pres- sure and another engine pressure as a function of corrected compressor rotor speed assuming that the stall margin is independent of compressor bleed, power extraction and degradation of engine efficien- cy. Control logic means to compensate for fan by- pass duct pressure losses in a system that controls the acceleration mode for a twin spool gas turbine engine so as to allow the engine to accelerate rap- idly with adequate stall margin by simulating a com- CM pressor stall limit. The stall limit is attained by gen- -5I8.7' FIG. I < erating a limiting ratio of burner pressure and an- other engine pressure as a function of corrected CM LO compressor rotor speed assuming that the stall mar- gin is independent of compressor bleed, power ex- traction and degradation of engine efficiency.
    [Show full text]
  • Airplane Flying Handbook (FAA-H-8083-3B) Chapter 15
    Chapter 15 Transition to Jet-Powered Airplanes Introduction This chapter contains an overview of jet powered airplane operations. The information contained in this chapter is meant to be a useful preparation for, and a supplement to, formal and structured jet airplane qualification training. The intent of this chapter is to provide information on the major differences a pilot will encounter when transitioning to jet powered airplanes. In order to achieve this in a logical manner, the major differences between jet powered airplanes and piston powered airplanes have been approached by addressing two distinct areas: differences in technology, or how the airplane itself differs; and differences in pilot technique, or how the pilot addresses the technological differences through the application of different techniques. For airplane-specific information, a pilot should refer to the FAA-approved Airplane Flight Manual for that airplane. 15-1 Jet Engine Basics Although the propeller-driven airplane is not nearly as efficient as the jet, particularly at the higher altitudes and cruising A jet engine is a gas turbine engine. A jet engine develops speeds required in modern aviation, one of the few advantages thrust by accelerating a relatively small mass of air to very the propeller-driven airplane has over the jet is that maximum high velocity, as opposed to a propeller, which develops thrust is available almost at the start of the takeoff roll. Initial thrust by accelerating a much larger mass of air to a much thrust output of the jet engine on takeoff is relatively lower slower velocity. and does not reach peak efficiency until the higher speeds.
    [Show full text]
  • Airplane Turboprop Engines Basic Familiarization
    AIRPLANE TURBOPROP ENGINES BASIC FAMILIARIZATION INTRODUCTION Many of today's airplanes are powered by turboprop engines. These engines are quite reliable, providing years of trouble-free service. However, because of the rarity of turboprop engine malfunctions, and the limitations of simulating those malfunctions, many flight crews have felt unprepared to diagnose engine malfunctions that have occurred. The purpose of this text is to provide straightforward material to give flight crews the basics of airplane engine operational theory. This text will also provide pertinent information about malfunctions that may be encountered during the operation of turboprop-powered airplanes. It is not the purpose of this text to supersede or replace more detailed instructional texts or to suggest limiting the flight crew's understanding and working knowledge of airplane turbine engine operation and malfunctions to the topics and depth covered here. Upon completing this material, flight crews should understand that some engine malfunctions can feel and sound more severe than anything they have ever experienced; however, the airplane is still flyable, and the first priority of the flight crew should remain "fly the airplane." PROPULSION Figure 1 showing balloon with no escape path for the air inside. All forces are balanced. Propulsion is the net force that results from unequal pressures. Gas (air) under pressure in a sealed container exerts equal pressure on all surfaces of the container; therefore, all the forces are balanced and there are no forces to make the container move. 1 If there is a hole in the container, gas (air) cannot push against that hole and the gas escapes.
    [Show full text]
  • CFM56 General Engine Certification & Testing
    Flight Operations Support Tuesday, 13 December 2005 OOvveerrvviieeww Flight Ops Support 2 CCFFMM5566 GGeenneerraall TTeecchhnniiccaall FFeeaattuurreess EEnnggiinnee CCeerrttiiffiiccaattiioonn && TTeessttiinngg OOppeerraattiioonnaall CChhaarraacctteerriissttccss EEGGTTMMaarrggiinn,, OOAATTLL RReedduucceedd TTaakkeeOOffff TThhrruusstt NNoorrmmaall OOppeerraattiinngg CCoonnssiiddeerraattiioonnss FFlliigghhtt pphhaasseess,, ooppss rreeccoommmmeennddaattiioonnss CFM PROPRIETARY INFORMATION Subject to restrictions on the cover or first pa ge Flight Operations Support Tuesday, 13 December 2005 CCFFMM iissaa JJooiinntt CCoommppaannyyooff 3 SSnneeccmmaa,, FFrraannccee AAnndd GGeenneerraall EElleeccttrriicc CCoo..,, UU..SS..AA.. CFM PROPRIETARY INFORMATION Subject to restrictions on the cover or first pa ge Flight Operations Support Tuesday, 13 December 2005 CFM General 4 - LP system - Installations A jointly owned - Gearbox company - Controls and accessories EFECTIVE 50/50 WORK SPLIT An effective division of labor dictates exactly how the companies allocate their manufacturing resources. This work - Core engine split acknowledges the - System integration technological - FADEC/MEC systems achievements of both The CFM56 core is based on the GE F101 engine Snecma's and GE (developed for the B-1 bomber) and employs a single-stage high-pressure turbine to drive a nine- Aircraft Engines' stage compressor. Correspondingly, a Snecma respective advanced four- or five-stage, low-pressure turbine organizations drives the Snecma fan and booster. CFM PROPRIETARY
    [Show full text]