1、AEROSPACE STANDARD AS6502 Issued 2015-01 Aircraft Propulsion System Performance Nomenclature RATIONALE Aircraft propulsion technology continues to evolve and advance to meet changing requirements and challenges for improved performance and capabilities. This document addresses an industry need to ch
2、aracterize classical propulsion system performance parameter names, and describes the logical framework by which new names can be constructed. Nomenclature definitions issued by other industry organizations were reviewed and considered as well as the application of this standard to alternate engine
3、cycles. The contents of this document were, originally, a subset of AS755E. Due to the growing complexity of station numbering schemes described in AS755, and a desire to expand the nomenclature section to include a fuller representation of “classical” (legacy use) names, a decision was made to sepa
4、rate its “station numbering” and “nomenclature” content into two separate documents. This document, then, was created using the “nomenclature” half of AS755E. Both documents will continue to be improved and expanded as industry needs dictate. _ SAE Technical Standards Board Rules provide that: “This
5、 report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” SAE review
6、s each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2015 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval syste
7、m or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside USA) Fax: 724-776-0790 Email: CustomerServices
8、ae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AS6502 SAE INTERNATIONAL AS6502 Page 2 of 13 TABLE OF CONTENTS 1. SCOPE 3 2. REFERENCES 3 2.1 Applicable References 3 2.1.1 SAE Publicatio
9、ns . 3 2.1.2 ICAO Publications . 3 3. STATION DESIGNATION . 3 4. NOMENCLATURE 4 4.1 Basic Symbols . 4 4.1.1 Properties and Fundamental Parameters . 4 4.1.2 Commonly Used Ratios, Functions, Terms, etc. 5 4.2 Operating Symbols 5 4.3 Descriptive Symbols 6 4.3.1 Fluid Description . 6 4.3.2 Engine Descri
10、ption 6 4.3.3 General Description 7 4.4 Additional Notes 8 5. EXAMPLES . 8 5.1 Groups formed by basic symbols together with one or more descriptive symbols: 8 5.2 Groups formed by basic symbols together with descriptive symbols and station numbers: 9 6. NOMENCLATURE SUMMARY TABLE 10 7. NOTES 13 Tabl
11、e 1 Nomenclature summary 10 SAE INTERNATIONAL AS6502 Page 3 of 13 1. SCOPE 1.1 This SAE Aerospace Standard (AS) provides classical propulsion system performance parameter names for aircraft propulsion systems and their derivatives, and describes the logical framework by which new names can be constr
12、ucted. 1.2 The contents of this document were, originally, a subset of AS755E. Due to the growing complexity of station numbering schemes described in AS755, and a desire to expand the original documents nomenclature section to include a fuller representation of “classical” (legacy use) names, a dec
13、ision was made to separate its “station numbering” and “nomenclature” content into two separate documents. This document, then, was created using the “nomenclature” half of AS755E. Both documents will continue to be improved and revised as industry needs dictate. 1.3 The parameter naming conventions
14、 presented herein are for use in all communications concerning propulsion system performance such as computer programs, data reduction, design activities, and published documents. They are intended to facilitate calculations by the program user without unduly restricting the method of calculation us
15、ed by the program supplier. 1.4 The list of symbols presented herein will be used for identification of input and output parameters. These symbols are not required to be used as internal parameter names within the engine subprogram. 2. REFERENCES 2.1 Applicable References The following documents con
16、tain material relevant to the subject area of this document, but do not form a part of this document. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AS75
17、5 Aircraft Propulsion System Performance Station Designation and Nomenclature ARP5571 Gas Turbine Engine Performance Presentation and Nomenclature for Object-Oriented Computer Programs 2.1.2 ICAO Publications Available from International Civil Aviation Organization, 999 University Street, Montreal,
18、Quebec H3C 5H7, Canada, Tel: +1 514-954-8219, http:/www.icao.int/ Doc 7488 International Civil Aviation Organization, Manual of the ICAO Standard Atmosphere 3. STATION DESIGNATION AS755 describes station numbering systems used to designate points in the gas flow path that are significant to propulsi
19、on system performance definitions. The performance parameter naming conventions outlined in this document rely, somewhat, on the station numbering schemes described in AS755. Refer to that document for more detail. For computer symbols in this document, the following convention will be used: a. deno
20、tes the numeric symbol b. O denotes the alphabetic symbol SAE INTERNATIONAL AS6502 Page 4 of 13 4. NOMENCLATURE The nomenclature defined in the following sections has been compiled to provide a uniform method of naming variables associated with airbreathing propulsion systems. Its use is encouraged
21、for all communications involving propulsion system performance including computer programs (for object-oriented programs, see ARP5571). Two columns of symbols follow the variable descriptions. The first column presents the recommended symbols for general use. The second column presents alternate sym
22、bols which are retained because of their widespread use. Subscripts and superscripts, Greek letters and other specialized characters have been avoided in the recommended symbols. Historically, symbols have been restricted to upper case letters to be compatible with most computer languages. Modern co
23、mputer platforms and object-oriented computer languages, however, make extensive use of case-sensitive names. The symbols in this section may be rendered in mixed case as permitted by the conventions of such systems. 4.1 Basic Symbols This section includes the symbols used to derive basic parameters
24、 and will normally form the leading letter, or letters, in compound groups. Most of these symbols will be expanded by the addition of a station number, component symbol or stream identification as described in later paragraphs. Examples of some resulting compound groups are contained in Section 5. 4
25、.1.1 Properties and Fundamental Parameters Note that in all sections of this document the alternate form of the symbol is in parentheses. Area, geometric A Altitude, pressure ALT Angle ANG (AN, , , , etc.) Density RHO () Efficiency, adiabatic E (, ETA) Enthalpy total, per unit mass H (h) Entropy tot
26、al, per unit mass S (s) Force, Thrust F Frequency FY (f) Heat Transfer Rate QU (Q) Inertia - polar moment (see 4.4.3) J (XJ) Length L (XL) Mass GM (m) Mass flow W Power PW Pressure - total P Rotational speed N (XN) Temperature - total T Time TIME (t) Torque TRQ Velocity V Viscosity VIS Volume VOL (v
27、) Weight WT (w) SAE INTERNATIONAL AS6502 Page 5 of 13 4.1.2 Commonly Used Ratios, Functions, Terms, etc. This paragraph contains symbol groupings which, although they are exceptions to the general system, have been retained because of their widespread use in industry. Blow-out margin BOM Bypass rati
28、o BPR Coefficient or constant C Compressor Discharge Pressure CDP Compressor Discharge Temperature CDT Delta (pressure/standard sea level pressure) DEL () Discharge coefficient CD Drag FD Emissions index EI Engine pressure ratio EPR Entropy function PHI () Error Y Exhaust gas temperature EGT Fuel Ai
29、r Ratio FAR Fuel lower heating value FHV Gas constant (per unit mass) R Input or given parameter value Z Inter-Turbine Temperature ITT Light-off margin LOM (XLOM) Mach number M (XM) Mechanical equivalent of heat CJ Molecular weight MW (XMW) Power lever angle PLA Propeller Advance Ratio QJ (J) Propel
30、ler Blade Angle BETA () Ratio of specific heats GAM () Relative humidity RH Reynolds number RE Reynolds number index RNI Rotor blade angular position ROP Specific fuel consumption SFC Specific gravity SG Specific heat at constant pressure CP Specific humidity SH Surge margin SM Stator Blade angular
31、position STP Tangential wheel speed U Theta (temperature/standard sea level temperature) TH () Velocity dynamic head VH (q) Velocity of sound VS (a) Water (liquid) air ratio WARL Water (vapor) air ratio WAR 4.2 Operating Symbols The symbols in this paragraph describe operations and will normally be
32、imbedded in compound groups. Derivative with respect to time U (d/dt) Derivative with respect to following symbol U_ (d/d_) Difference (see 4.4.2) D (- or ) Quotient, Ratio (when not followed by U) Q (/) Square Root R ( ) SAE INTERNATIONAL AS6502 Page 6 of 13 4.3 Descriptive Symbols This paragraph i
33、ncludes recommended symbols that describe the basic parameters and will usually be the trailing letter, or letters, in compound groups. It is subdivided into a section describing the fluid, a section containing symbols describing parts of the engine, and a general section. 4.3.1 Fluid Description So
34、me properties and fundamental parameters (e.g., pressure, mass flow) which refer to the fluid may require additional description to indicate the composition and use of the fluid. The following symbols should be appended directly after the basic symbols of 4.1 (see 4.4.1 for additional notes on fluid
35、 description). Air A Bleed B Boundary layer BL Coolant CL (C) Fuel F Leakage LK (L) Oxidizer OX Water W 4.3.2 Engine Description 4.3.2.1 Some parameters which are associated with propulsion system components or turbine engine rotors (e.g., efficiency, rotor speed, surge margin, torque) require more
36、specific description. This should be provided by appending the station number (see Section 3) at the inlet to the relevant component or rotor after the basic symbols of 4.1. An alternate method, included because of its widespread use in industry, is to append the following symbols: Afterburner AB Bo
37、at-tail BT Burner B Compressor C Engine E Heat Exchanger EX Gearbox GB High pressure component or rotor H Intermediate pressure component or rotor I Low pressure component or rotor L Power turbine or rotor PT Turbine T 4.3.2.2 Some propulsion system components may require specific identification. In
38、 these cases, the identifier should be appended to the station number: Propeller P Rocket RK (R) SAE INTERNATIONAL AS6502 Page 7 of 13 4.3.3 General Description The following general descriptive symbols should be appended after the basic symbols of 4.1: Average A (AV) Ambient AMB Calculated CAL Cali
39、brated airspeed CAS Conductivity K Controlled variable C Diameter DI Distortion DIST Effective E Equivalent airspeed EAS Extraction X Gross G High (maximum) H Horizontal HOR Hub HUB Ideal I Indicated airspeed IAS Installed IN Low (minimum) L Map value M Measured ME Mixed M (MX) Net N Parasitic PAR P
40、ercent PCT (PC) Polytropic P Radius RAD Ram RAM Referred (corrected) R Relative REL Reverse REV (RV) Sea level SL Sensed parameter SE Shaft delivery (output) SD Standard STD Static S Swirl SW Tip TIP Total T True airspeed TAS Vertical VER SAE INTERNATIONAL AS6502 Page 8 of 13 4.4 Additional Notes 4.
41、4.1 To describe the position within the propulsion system of parameters associated with a fluid, the numbers detailed in the station identification system of Section 3 should be appended. The letters of 4.3.1 should precede these station numbers if both are required. 4.4.2 The imbedded D, which iden
42、tifies a difference (see 4.2) should be used wherever the compound group of symbols is of an acceptable length. However, D may also be used as a leading symbol of a difference parameter when contraction of the compound group of symbols is necessary. 4.4.3 The symbol J (polar moment of inertia) shoul
43、d be appended by a component identification symbol (4.3.2). The component should be that to which all associated inertias are algebraically referred. 4.4.4 A gas property followed by S denotes a static quantity; otherwise a stagnation condition is implied. 4.4.5 The symbol X may be prefixed to leadi
44、ng symbols I, J, K, L, M, N for computer purposes. 4.4.6 It is recognized that it may be required to limit the number of characters per parameter name. When this limitation is not compatible with the recommended nomenclature of this document, the parameter name may be shortened. For a complex groupi
45、ng, a leading G is recommended. 5. EXAMPLES Some examples of compound groups are contained in this paragraph. 5.1 Groups formed by basic symbols together with one or more descriptive symbols: AE Effective area ANGBT Boat-tail angle ANGSW Swirl angle CF Thrust coefficient CFG Gross thrust coefficient
46、 CFP Propeller thrust coefficient CPSTD Standard sea level pressure CPW Propeller power coefficient CQU Overall heat transfer coefficient CQUBL Heat transfer film (boundary layer) coefficient CQUK Thermal conductivity CQUL Coefficient of linear thermal expansion CR Universal gas constant CTSTD Stand
47、ard sea level temperature CV Nozzle velocity coefficient DTAMB Ambient temp. minus ISA temperature DPW Unbalanced power DTRQ Unbalanced torque EGB Gearbox efficiency EP Polytropic efficiency ERAM Ram pressure recovery ETAP Propeller efficiency FG Gross thrust FGI Ideal gross thrust FN Net thrust FNI
48、N Installed net thrust FRAM Ram drag HF Enthalpy of fuel HS Static enthalpy NQGB Gearbox speed ratio, relative to driving speed NQP Counter-rotating speed ratio of propellers SAE INTERNATIONAL AS6502 Page 9 of 13 NSD Delivered shaft speed PAMB Ambient pressure PB Bleed flow total pressure PS Static
49、pressure PWPAR Parasitic power PWQPW Power split in counter-rotating components, with respect to total power PWSD Delivered shaft power PWX Power extraction SFCIN Installed specific fuel consumption SGF Fuel specific gravity TAMB Ambient temperature TLK Total temperature of leakage gas TRQSD Delivered shaft torque TS Static temperature UTIP Tange
