r^^^j-^-MSSC-raeSft^*«^:- ^-'-.■szu- FSTC-HI-23-766-70 AtMY MATEtlil COMMAND U.S. ARMY FOREIGN SCIENCE AND TECHNOLOGY CENTER [>• STARTING OF AIRCRAFT GAS TURBINE ENGINES By D D C M, A. ALABIN B. M. KAxS YU. A. LITVINOV APR 24 1972 E SUBJECT COUNTRY: RUSSIA Thia document is a rendition of the original foreign text without any analytical or editorial aoment. Reproduced by NATIONAL TECHNICAL INFORMATION SERVICE Springfield, Va. 22151 Approved for public release; distribution unlimited. m o UHCLASSIFIED a»ctwitT cu««tac«ti— DOCUMENT COHTROL DATA • 11.1» I» z%m—i»m4i i. onieiN&riM« ACTIVITY fC«i»wf mu^rnt) . MBVOIIT aCCUMITT CLAMiriCATIOM Foreign Science and Technology Center Unclassified US Army Materiel Coamand Department of the Army i ac^onr TITLC Starting of Aircraft Gas Turbine Engines *. OCSCRIVTIVC NOTca (Tn* »I mwrt m* tmctmmlrm «MM) Translation M. A. Alabin, B. M. Kats, Yu. A. Litvinov • NC'OKT D»TK T«. TOTäW MO. OF ^««ca i*. wo- OP Hera 12 January 1972 227 N/A M. CONTRACT OR GRANT NO. »m. oRiaiNATO«*a scRoRT NutMCRiai b. PROJF^T NO. FSTC-Hr-23- 766-70 .T/02301 230*! e OTHCK RCRORT NOiai (A*? t I mar *• —10*4 mim nßift) K-0571 * Requester Avn Systems Cmd 10. OltTRiBUTIOH STATCMKKT Approved for public release; distribution unlimited. II SURRUCMCNTARV NOTES It. aRONaORINS HILITARV ACTIVITY US Army Foreign Science and Techr-ology Center 1$. ABSTRACT Examined in this book is the theory of starting aviation gas turbine engines on the ground and in flight. This discussion goes into considerably greater detail than previously published literature on aviation engines. The design principles and operating features of individual components of the starter system and engine accessories during start up are examined, the methods of calculating the starting characteristics of various types of engines on the ground and in flight are set forth and the physical essence of starting processes is explained. The influence of various factors on engine starting reliability is examined in detail. Chief attention is devoted to investigation of the starting processes of single rotor turbojet engines. Certain features of starting of turboprop and turbojet engines of the two-rotor design are also discussed. Recommendations on the choice of starter system type for aircraft engines are made on the basis of analyses of power balance of gas turbine engine starting, possible causes of unreliable starting and efficiency of the various starter systems. Methods of calculating engine parameters in the autorotation and low rpm regimes and engine starting reliability limits in flight are given, which can be used in the testing and operation of gas uurbine engines. ff%ff% fMM 4 M ■»•4 «CRi-AeKa o» 'mm i«»s. i JAM M. •MICH ia DU « 4MV ••! ^ 19 OMOkCTC ro« ADMV MS. (•evilly Claaalfle«w•3 05 ^..«^►-.«Mrt«^,^^, LINK A LIM« • H*y «•■»• Ml.« ft«!.* MOLK Gas turbine engine Aircraft engine Gas turbine starter Engine starter system Turbojet engine Turboprop engine Turbine rotor Turbine design Country Code: Russia Subject Code: 01, 21 UNCLASSIFIE: lSatecwurtitlvy CCllaaaa aineattoii mmaLs mmmm TECHNICAL TRANSLATION ff8tC-W-23- 766-70 ENGLISH TITLZ: Siartlng of Aircraft Gas. Turbine Engines FOREIGN TITLE: Zaoysj Aviatsionnykh Gazoturbinnykh Dvigatelei AUTHOR: M. A, Alabin, B. M. Kats, Yu. A. Litvinov SOURCE: Zapusk Aviatsionnykh Gazoturbinnykh Dvigateley, Russian, "Mashinostroyeniye" Publishing House, 1968, 227 pages Translated for FSTC by ACSI Details of illustrations in this document may be better NOTICE -studied on microticha The contents of this publication have been translated as presented in the original text. No attempt has been made to verify the accuracy of any statement contained herein. This translation is published with a minimum of copy editing and graphics preparation in order to expedite the dissemination of information. Requests for additional copies of this document should be addressed to Department A, National Technical Information Service, Springfield, Virginia 22151. Approved for public release; distribution unlimited. ja»Mia.;.j.i»Maialw..jji«a^fat| -J STARTING OF AIRCRAFT GAS TURBINE ENGINES [Book by M. A. Alabin, B. M. Kats, Yu. A. Litvinov; Moscow, Zapusk Aviatsionnykh Gazoturbinnykh Dvigateley, Russian, "Mashinostroyeniye" Publishing House, 1968, 227 pages] "ll--J"""'"-—~-""'"""''""--- - fiiiy^iaMifiiliffflliilgiiatt' ^ UDC 629.7.036-572/-576.001 ANNOTATION Examined in this book is the theory of starting aviation gas turbine engines on the ground and in flight. This discussion goes into considerably greater detail than previously published literature on aviation engines. The design principles and operating features of individual components of the starter system and engine accessories during start-up are examined, the methods of calculating the starting characteristics of various types of engines on the ground and in flight are set forth and the physical essence of starting processes is explained. The influence of various factors on engine starting reliability is examined in detail. Chief attention is devoted to investigation of the starting processes of single-rotor turbojet engines. Certain features of starting of turboprop and turbojet engines of the two-rotor design are also discussed. Recommendations on the choice of starter system type for aircraft engines are made on the basis of analyses of power balance of gas turbine engine starting, possible causes of unreliable starting and efficiency of the various starter systems. Methods of calculating engine parameters in the autorotation and low rpm regimes and engine starting reliability limits in flight are given, which can be used in the testing and operation of gas turbine engines. The book is intended for engineers and technicians in the aviation industry and civil and military aviation. It may also be of use to teachers and students in related aviation courses. üajüaaiüüiB PREFACE The rapid development of aviation gas turbine engines (GTE) and their extensive adoption necessitate a special study of the characteristics of the engine starting process and improvement of starting equipment. In aviation these characteristics reflect the preparedness of aircraft for flight, and the operation of the components of the starting system has a direct influence on flight safety, engine reliability and service life. The purpose of this book is to assist the large community of specialists of the aviation industry, military and civil aviation in the design, testing and operation of engine starter systems. The book consists of three parts. Part One contains basic information concerning aviation GTE starter systems, analysis of the starting process and classification of starter systems. Examined in the.corresponding sections of Part One are the principles of design and operation of the main components of the starter system --of various types of starters (rotor accelerator units), components of the starting control system, starter fuel system, etc. Part Two is devoted to the processes of starting GTE on the ground, analytical characteristics of the moments acting on the engine rotor, dynamic equilibrium of rotor during starting process. The influence of various design and operation fa-, tors on starting reliability is analyzed and nomograms are included for calc'i1.atiop of the basic parameters of the starting process and starter systems. Part Three deals with the development of theory and analysis of the physical essence of in-flight starting processes and includes an evaluation of the effect of various factors on GTE starting reliability. In-flight engine starting processes are examined and their parameters in the low rpm state are analyzed in application to subsonic speeds. Engine parameters in the autorotation mode and the dependence of the mode of auto- rotation on various factors are analyzed for velocities M <_ 3. Many of the graphs are plotted in relative coordinates, and the values of the parameters in the low rpm state are used as 100%. "°fli"i^Ma-''t""""'j'—-' The diagrams of the starter systems and designs of rotor preaccelerator units, presented in Part One of this book, were borrowed from Soviet and foreign sources. Some of the sections contain materials generously given the authors by candidate of technical sciences N. F. Dubovkin. [ i All units of measurement used in this book are given in the MKS [meter- kilogram-second] and MKGSS [Meter-kilogram force-second] systems. Tue follow- ing table may be used as an aid to conversion to the units of the interna- tional system IS: Symbol of units of measurement in Ratio of units of measure- Parameter systems ment MKGSS IS Force kg N 1 kg = 9.81 N Mass kg'sec2/m H 1 kg'sec2/m = 9.81 kg Pressure kg/m2 N/m2 1 kg/m2 =9.81 N/m2 Torque (moment of force) kg-m N'm 1 kg'm = 9.81 N«m Effort, energy kg*m J 1 kg-m = 9.81 J Moment of inertia (dynamic) kg•m«sec2 kg-m2 1 kg«m«sec2 = 9.81 kg-m2 Power kg'm/sec W 1 kg-m/sec = 9.81 W 1 hp = 735.5 W The authors express their sincere gratitude to the reviewer -- doctor of technical sciences B. A. Cherkasov, who offered many valuable recommsnda- tions for improvement of the manuscript. They will also acknowledge the readers for all critical comments and requests, which should be addressed to "Mashincstroyeniye" Publishing House (Moscow, K-51, Petrovka, 24). -2- mmnmm PRINCIPAL SYMBOLS G -- air flow rate through compressor in kg/sec; G -- gas flow rate through turbine in kg/sec; g Gf -- fuel flow rate through engine in kg/hr; p* — total pressure of working medium through engine duct in kg/cm2; p - static pressure of working medium through engine duct in kg/cm2; T^ -- air compression ratio in compressor; TT* — air compression'ratio in turbine; K -- compressor stability factor; X -- compressor stability factor in terms of fuel flow rate; r f nj* -- compressor efficiency in terms of stagnation flow parameters; n* — turbine efficiency in terms of stagnation flow parameters; T — absolute temperature of working meditun in engine duct in 0K; N -- power in hp; M -- torque in kg-m; J. -- polar moment of inertia in kg-m-sec2; AN -- surplus power in hp; n -- rpm n -- rpm of engine rotor at ignition of main fuel; 1 n -- final motoring rpm of engine rotor by starter; f n -- engine rotor rpm at which the turbine moment is equal to the engine resistance moment; n -- engine rotor rpm at moment of starter disengagement; 9 n -- engine rotor rpm in low power state; H . -- adiabatic heat drop in kcal/kg; ad J -- enthalpy of working medium in kcal/kg; L . -- adiabatic work of 1 kg of working medium in kg-m/kg; ad R -- gas constant in kg-m/kg'deg; -3- ■^^^^^..^^«^■.«.a»-^ H — calorific value of fuel in kcal/kg; c -- heat capacity of working medium at constant pressure in kcal/kg*deg; c -- heat capacity of working medium at constant volume in kcal/kg»deg; v C -- absolute velocity of working medium in m/sec; W — relative velocity of working medium in m/sec; V — flight velocity in km/hour; F -- cross section area in m2; k -- adiabatic index; m — mass in kg«sec2/«; g -- acceleration of gravity in m/sec2; M -- Mach number of flight; H -- flight altitude in meters; T* — ratio of stagnation temperatures of air behind and in front of the compressor; T? — ratio of stagnation temperatures at the end of the combustion chamber aad at compressor exhaust; T* -- ratio of stagnation temperatures in front of and behind engine turbine; T -- duration of starter system operation in sec; S • s T -- starting time (time required for going into the low rpm state) in sec; a -- pressure recovery coefficient; Indices re -- parameters reduced to MSA [International Standard Atmosphere] s — parameters in steady state starter operation modes; n -- parameters in nonsteady starter operation modes; lim — compressor parameters at stability limit; k -- parameters at compressor exhaust; g -- parameters at turbine intake; t -- parameters at turbine exhaust; c -- parameters at exit of reactive nozzle; by— parameters through engine duct with bypass of air from compressor; a — axial component of velocity; ins -- instrument values of parameter; s.s -- parameters pertaining to starter system. -4- üSJüämtäimtUMmimm