1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and enginee ring sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefr
2、om, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invit es your written comments and suggestions.Copyright 1997 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.
3、S.A.QUESTIONS REGARDING THIS DOCUMENT: (412) 772-8510 FAX: (412) 776-0243TO PLACE A DOCUMENT ORDER: (412) 776-4970 FAX: (412) 776-0790400 Commonwealth Drive, Warrendale, PA 15096-0001AEROS PACE RECOMMENDED PRACTICESubmitted for recognition as an American National StandardARP1217 RE V. AIssued 1979-0
4、5Reaffirmed 1989-05Revised 1997-05Superseding ARP1217I nstrumentation R equirements for T urboshaftE ngine P erformance M easurementsFOREWORDChanges in this revision are format/editorial only.1. SCOPE: This SAE Aerospace Recommended Practice (ARP) defines the measurement parameters that may be used
5、by a pilot or operator to monitor the thermodynamic health of a turboshaft engine in a helicopter and the measurement system accuracies desired.2. REFERENCES: There are no referenced publications specified herein.3. DEFINITIONS: 3.1 Condition Monitoring: Engine condition monitoring involves the obse
6、rvation of various measured parameters to detect changes with operating time for a given operating condition.3.2 Diagnostics: Proper interpretation of the monitored parameters allows the observer to determine the health of the engine. If changes in the parameters have not taken place, operation can
7、be continued. However, if a change is noted, the cause can be diagnosed and appropriate action taken.SAE ARP1217 Revision A- 2 -4. DISCUSSION: During the past few years, interest has grown in the concept of “on-condition“ maintenance, which permits the removal of an engine when a monitoring device s
8、uch as a chip detector or vibration sensor indicates that the engine requires maintenance action. Similarly, if the performance of an engine and its components can be monitored, the engine need not be removed from the helicopter for overhaul at a pre-determined time between overhaul (TBO), but only
9、if engine performance deterioration exceeds specified limits. Simultaneously, with proper location of the measuring sensors, it is possible to diagnose where the performance deterioration has occurred so that appropriate maintenance action can be taken. While the concept of “on-condition“ maintenanc
10、e may not be universally applicable, it may offer reduced operating costs.The determination of the thermodynamic health of an engine traditionally has involved the measurement of a certain set of cycle parameters. Newer techniques involve measuring changes in component characteristics with time. In
11、the case of the latter technique measurement, repeatability is more important than absolute accuracy.The recommendations in paragraph 5 are intended for either technique.Whether the more traditional analysis or newer technique is used, studies have shown that the measurement of the following paramet
12、ers are the most useful for determining changes in efficiencies and flow capacities of turboshaft engines with time.T 1 - Temperature at Inlet/Engine InterfaceP 1 - Pressure at Inlet/Engine InterfaceN 1 - Gas Generator Rotor SpeedN 2 - Power Turbine Rotor SpeedT 3 - Temperature at Compressor Dischar
13、geP S3 - Static Pressure at Compressor DischargeT 4.5 - Temperature at Power Turbine InletP S4.5 - Static Pressure at Power Turbine Inlet - Power Turbine Output TorqueW f - Engine Mass Fuel FlowIt should be understood that the above parameters can be used to monitor the condition of the full compres
14、sor and gas generator turbine consisting of either a single or dual rotor. In the majority of cases, isolating the fault to the compressor section or to the gas generator turbine section is sufficient to prescribe maintenance action.SAE ARP1217 Revision A- 3 -5. RECOMMENDATIONS: Depending on the mai
15、ntenance philosophy of a particular installation, some or all of the parameters listed in paragraph 4 might be utilized. The final choice of the parameters and the condition monitoring and diagnostic procedures to be employed should be performed in accordance with methods described in the installati
16、on manual or in accordance with methods agreed by the user with the helicopter manufacturer. As a minimum, provisions should be made for the pilot or operator to monitor T 1 , P 1 , N 1 , N 2 , T 4.5 , and torque. With this in mind, the following are recommended accuracies and repeatabilities of the
17、 measurement systems:5.1 Engine Inlet Temperature (T 1 ): The temperature just ahead of the engine/airframe interface is normally used, since compressor inlet temperature is not directly measured. The present accuracy of measurement is 2 C. An accuracy of 1 C is desired. The present repeatability is
18、 0.1 C and is acceptable. Accuracy and repeatability is required over full scale.5.2 Engine Inlet Pressure (P 1 ): The inlet pressure is a direct function of altitude, flight speed, and ram pressure recovery. The variation of inlet pressure has a directly corresponding effect on power output. If bar
19、ometric pressure is used as an alternate to a direct measurement of P 1 , the accuracy of the altimeter at sea level should be within 50 ft (152 cm), the equivalent of 0.2% in inlet pressure. The present repeatability is 50 ft (152 cm), and is acceptable. Accuracy and repeatability are required over
20、 full scale.5.3 Gas Generator Speed (N 1 ): The accuracy of speed measurement can have an important bearing on performance determination. Using speed as a prime parameter requires better instrumentation than is currently available. The present accuracy is .25% and repeatability is .1% and are accept
21、able and required above 50%.5.4 Power Turbine Speed (N 2 ): Where power turbine speed and output torque are used to determine power, the accuracy of power determination will vary directly with the accuracy of power turbine speed measurement. The present accuracy is .25% and repeatability is .1% and
22、are acceptable and required above 80% scale.5.5 Compressor Discharge Temperature (T 3 ): In conjunction with other parameters for a given operating condition, T 3 is used to assess changes in overall compressor efficiency and flow capacity. The present accuracy is 5 C. An accuracy of 3C is desired.
23、The present repeatability is 3 C, but 1 C is desired. Accuracy and repeatability are required over the full scale.SAE ARP1217 Revision A- 4 -5.6 Compressor Discharge Pressure (P S3 ): Measurement of P S3 is also used to monitor changes in compressor efficiency and flow capacity. Pressure indicating
24、systems currently achieve an accuracy of 2% and repeatability of 1%. A repeatability of .25% is desired. Accuracy and repeatability are required over the full range.5.7 Power Turbine Inlet Temperature (T 4.5 ): In conjunction with other parameters for a given operating condition, T 4.5 is used to mo
25、nitor changes in high pressure turbine efficiency and turbine nozzle area. A change in T 4.5 could also indicate a temperature profile change, a harness failure, or an error in the readout for the given operating condition. The present accuracy is 5 C. An accuracy of 3 C is desired. The present repe
26、atability is 3 C, but 1 C is desired. Accuracy and repeatability are required above 25% scale.5.8 Power Turbine Inlet Static Pressure (P S4.5 ): Measurement of this parameter is also used to determine changes in high pressure turbine efficiency and nozzle area. The present accuracy is 2%. The presen
27、t repeatability is 1%, but .25% is desired. Accuracy and repeatability are required over the full scale.5.9 Output Torque ( ): For a given operating condition, measurement of torque is used to monitor changes in shaft horsepower. In conjunction with other parameters, shaft horsepower is used to asse
28、ss changes in power turbine efficiency, turbine cooling flow, and power turbine area. The present accuracy is 3%. An accuracy of 1% is desired. The present repeatability is 0.5% and is acceptable. Accuracy and repeatability are required over the full scale.5.10 Engine Mass Fuel Flow (W f ): Fuel flo
29、w is used to determine engine specific fuel consumption. In conjunction with other parameters, fuel flow can also be used to determine changes in power turbine efficiency and nozzle area, and compressor airflow. The present accuracy is 2%. The repeatability is 0.5% and is acceptable. Accuracy and repeatability are required over the full scale.PREPARED BY SAE COMMITTEE S-12, HELICOPTER POWERPLANT
