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4、 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR5450AEROSPACEINFORMATION REPORTAIR5450Issued 2008-08 Reaffirmed 2014-06 Advanced
5、 Ducted Propulsor In-Flight Thrust Determination RATIONALEAIR5450 has been reaffirmed to comply with the SAE five-year review policy. INTRODUCTION Prior to 1978, there were no industry or government standards for determining in-flight thrust. In 1978, the SAE Propulsion Division and the Aerospace Co
6、uncil organized a group of knowledgeable experts into the SAE E-33 Committee to address this subject on a technical basis. In 1985 the Committee published AIR1703, which discussed methodologies and examples of in-flight thrust determination for low bypass turbofan engines and a companion document, A
7、IR1678, which addressed the process for estimating uncertainty of in-flight thrust. Since then, the E-33 Committee and its Subcommittees have published a series of documents on the subject: 1986: SP-674 - In-flight Thrust Determination and Uncertainty This document contains both AIR1703 and AIR1678
8、with six explanatory papers containing examples of using the methodologies and other explanatory material. 1993: AIR4065 - Propeller/Propfan In-flight Thrust Performance This document addresses in-flight thrust determination issues particular to propeller powered aircraft. 1998: AIR4979 - Estimation
9、 of Measurement Uncertainty in Engine Tests Based on NATO AGARD Uniform Engine Test Program This document describes a “round robin” test program to determine typical bias/systematic errors associated with world class engine test facilities in North America and Europe. The document describes test res
10、ults relating to facility random and systematic measurement uncertainty determined from comparison testing of a J-57 engine in various altitude (ATF) and sea level (GLTF) test facilities. 1998: AIR5020 - Time Dependant In-flight Thrust Determination This document addresses use and limitation of usin
11、g time dependant “quasi-steady” measurements made during aircraft maneuvers to determine in-flight thrust 2000: AIR1678A - A refined update of the original AIR1678 consistent with other world standards (ASME PTC-19.1) 2007: AIR5925 - Measured Uncertainty Applied to Cost Effective Testing This docume
12、nt addresses utilization of uncertainty methodology to reduce test costs by choosing optimum instrumentation and measurement techniques. The E-33 Committee is also in the process of revising one AIR document: AIR1703A - In-flight Thrust Determination This document is a revision of the original AIR17
13、03 to make the presentation and format clearer and easier to understand, based on input from users. It also modernizes and expands the examples and other explanatory material. The current document (AIR5450) and all of the above documents have been written to be “stand alone”, and each is useful in i
14、ts own right. The methods and processes described in them have been widely used throughout the industry, in the United States and around the world. They are, however, closely interconnected, and together, provide a broad coverage of the in-flight thrust and uncertainty determination processes. They
15、are all consistent in fundamental methodologies and processes. They provide information to arrive at a sound process to determine in-flight thrust/ uncertainty for the various types of powerplants propelling modern aircraft. The purpose of the current document is to present information and guidance
16、on the selection of methods (including the effects on uncertainty) to predict and assess propulsion system thrust during flight development programs of Advanced Ducted Propulsor (ADP) engines. The document is intended to be a technical guide, but not a standard or legal document. It presents a varie
17、ty of test options and correlation methods for thrust determination that may be considered for the new generation of high bypass ratio, low fan pressure ratio Advanced Ducted Propulsor (ADP) turbofan engines. These potentially larger high bypass ratio engines may preclude the use of conventional tes
18、ting methods and facilities. Thrust determination methods for turbojets and lower bypass ratio turbofans were documented in AIR1703, and open rotor propeller/propfan in-flight thrust determination was addressed in AIR4065. There are several distinctly different methods that can be used for these two
19、 categories of propulsion systems. The ADP thrust characteristics fall between these extremes. The intention of this document is to provide information on the options available for ADP thrust determination, and an assessment of the various thrust correlating methods unique to the ADP. The reader wil
20、l note that frequent references are made to AIR1703 and AIR4065 because, depending on size and circumstance, those methods can still be appropriate, and the detailed descriptions are omitted herein. SAE INTERNATIONAL AIR5450 Page 2 of 392_ FOREWORD The technology advances and the demand for more eff
21、icient transport airframe/propulsion systems have led to the evolution of the Advanced Ducted Propulsor (ADP). Increases in propulsive efficiency have been most important in the changes in overall efficiency (by approximately a factor of two) from the earlier turbojets and turbofans to the current a
22、nd future high bypass ratio engines. Although no dividing line between ADP engines and conventional turbofan engines exists, ADP engines are characterized as having much higher bypass ratios (10) and much lower fan pressure ratios (1.5) than conventional turbofan engines. Two distinctive features co
23、mmon to many ADP engines are a geared fan drive and some form of variable geometry (variable nozzle area or variable pitch fan blades). Because of the lower fan pressure ratios and higher airflows, significant changes in the fan operating characteristics may arise due to Mach number and installation
24、 effects. Furthermore, increased thrust sensitivity to measurement uncertainties requires improved thrust determination methods and test techniques. Ideally these methods need to address the airframe effects on the engine installed performance for the determination of both cruise thrust and low spee
25、d thrust. The ADP operating characteristics present additional new problems relative to accurate in-flight thrust determination. The larger ADP configurations may be too large for existing indoor and altitude test facilities. Some of the new problems are related to the very large size of these engin
26、e systems that can have twice the airflow and be 50 percent larger than conventional turbofans for the same thrust (see Figure 1). This makes them difficult to install without creating aerodynamic interference and nacelle/wing interactions that could affect wing performance, engine operation, and in
27、-flight thrust determination. Engine-out aerodynamic drag is high due to the large engine and nacelle cross sectional area. The large engine diameter, with potentially high scrubbed friction area, requires a short inlet that may lead to inlet distortion affecting airflow and fan exhaust pressures us
28、ed for in-flight thrust determination. Large, long-range transports are being developed and larger ones are being studied which require very high thrust levels that exceed 100,000 lb thrust. ADP engines at this thrust level can exceed 15 ft in diameter and 6,000 lb/s in corrected air flow as shown i
29、n Figure 1. These size and airflow levels greatly stretch or exceed the current full-scale altitude test facility capabilities and may require facility modification or further development to accommodate this engine size. Or, alternatively, new thrust determination methods must be considered. 2001801
30、601401201001 1.2 1.4 1.6 1.8Take-off Fan Pressure RatioADPConventionalTurbofan15 ft10 ft70006000500040003000200011.21.41.61.8Take-off Fan Pressure RatioADPConventionalTurbofanFanDiameter, in.Corrected AirFlow, lb/secFIGURE 1 - APPROXIMATE FAN DIAMETER AND AIR FLOW TO MEET 100,000 LB TAKE-OFF THRUST
31、The test altitude and airflow envelopes of three major full-scale engine Altitude Test Facilities (ATF) are shown in Figure 2. Typical climb airflow operating conditions for engines with fan diameters of 110 to 160 in are also shown. The Wilgoos and Pyestock (now closed) facility capabilities are ex
32、ceeded for engine fan diameters larger than about 110 in. For typical climb airflows, the AEDC facility will suffice at typical transport cruise altitudes (30,000 to 35,000 ft) for 110 to 140 in engines, but will be inadequate for the 160 in engine. The typical climb operating conditions used in Fig
33、ure 2 are compared in Figure 3 with the flight envelope of a typical long range transport aircraft; potential maximum operating conditions are identified. Engine airflow at these maximum conditions will be higher than shown in Figure 2 and thus the applicability of existing ATFs will be further limi
34、ted. Alternative calibration and correlation methodologies need to be developed since developing the appropriate altitude test facility and capability would be extremely costly, and the associated cost of testing would also be extremely high. SAE INTERNATIONAL AIR5450 Page 3 of 392_ FIGURE 2 - ATF T
35、EST ENVELOPES COMPARED WITH POTENTIAL ADP AIRFLOW REQUIREMENTS Relative to conventional turbofan engines, ADP engines are potentially more sensitive to external flow field effects. Operating line shifts will affect the exit profiles and pressure losses that have significantly greater effects on ADP
36、in-flight thrust determination than for conventional turbofan engines where the shift is much less. Maximum airflow occurs at take-off for conventional turbofans while it occurs at maximum climb for the ADP. This makes full-flow static testing difficult for ADP engines without inlet air conditioning
37、 or waiting for cold weather. The difficulty of determining and correlating thrust coefficient for ADP in-flight thrust determination is exacerbated by the low fan nozzle-pressure-ratios of these engine systems. The sensitivity of ADP thrust to pressure measurement at sea level take-off is nearly th
38、ree times that of a conventional turbofan. In addition, due to the low fan pressure ratio at cruise, the gross to net thrust ratio is 3:1 to 4:1 for the ADP as compared to 2:1 to 2.5:1 for the conventional turbofan, which makes the task of accurately determining ADP in-flight thrust more difficult.
39、In the following sections this document explores a number of options for in-flight thrust determination of an ADP, and indicates potential accuracy of the methods. The determination of in-flight thrust is a complex task that depends upon careful planning and meticulous attention to detail throughout
40、 the test program. It is important that the participants involved (engine and airframe manufacturers, military service, government agency, commercial customer, etc.) agree at the outset on the definitions and the methods to be used for demonstration. Provision for flexibility and redundant methods a
41、re important to provide for unforeseen difficulties with a particular method. SAE INTERNATIONAL AIR5450 Page 4 of 392_ 50403020100-10-.2 0 .2 .4 .6 .8 1.21.0Flight Mach NumberTypical ClimbOperating ConditionsPotential MaximumOperating EnvelopeFIGURE 3 - TYPICAL TRANSPORT FLIGHT ENVELOPE WITH CLIMB O
42、PERATING CONDITIONS NOTED SAE INTERNATIONAL AIR5450 Page 5 of 392_ TABLE OF CONTENTS 1. SCOPE 11 1.1 Document Roadmap . 11 2. REFERENCES AND NOMENCLATURE . 13 2.1 Applicable Documents 13 2.1.1 SAE Publications. 13 2.2 Related Publications . 13 2.2.1 AGARD Publications. 13 2.2.2 AIAA Publications 13
43、2.2.3 Air Force Flight Dynamics Laboratory Publications 14 2.2.4 Sighard F. Hoerner Publication. 14 2.2.5 Book distributed by the School of Engineering, University of Dayton, Dayton, Ohio 45469 14 2.2.6 SAE Publications. 14 2.2.7 NASA Publications 14 2.3 Nomenclature 15 3. DEFINITIONS AND METHODOLOG
44、Y . 22 3.1 Dual-Stream (ADP) Engine Thrust . 23 4. ENGINE CONCEPTUAL DESIGN AND CONFIGURATIONS . 28 4.1 Propulsion Design. 28 4.2 Configuration Examples 32 4.2.1 Configuration Evolution. 33 4.3 Specific Configuration Examples 34 4.3.1 Pratt the performance and guarantee requirements; the thrust accu
45、racy required; the available budget; the power management parameter; etc. Sections 3 through 5 provide methodology and background information relevant to the challenges of integrating an ADP propulsion system into an aircraft. The key engineering activity to determine the validated in-flight thrust
46、performance is focused in Sections 6 through 9. SAE INTERNATIONAL AIR5450 Page 11 of 392_ Section 6 Thrust Method Options Identify Methods Section 7 Aerodynamic and Propulsion Testing Identify data sources and test requirements (Model, full scale, altitude) Section 9 Thrust Uncertainty Assessment Co
47、nfirm accuracy requirements Select final method Plan and execute program Section 8 In-Flight Thrust Validation In-flight thrust program Flight test program Thrust/drag closure Aircraft performance manual No Successful Validation? Yes Done SAE INTERNATIONAL AIR5450 Page 12 of 392_ 2. REFERENCES AND NOMENCLATURE 2.1 Applicable Documents The following publications form a part of this document to the extent specified herein. The latest issue of SAE public
