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Estimation of Measurement Uncertainty in Engine Tests Based on NATO AGARD Uniform Engine Test Program
- Aerospace Standard
- AIR4979
- Reaffirmed
Downloadable datasets available
Annotation ability available
Sector:
Issuing Committee:
Language:
English
Scope
The primary objective of this document is to describe the systematic and random measurement uncertainties which may be expected when testing gas turbine engines in a range of different test facilities. The documentation covers a "traditional" method for estimating pretest uncertainties and a "new" method for computing and comparing posttest uncertainties. To determine these posttest uncertainties, data generated during the AGARD Uniform Engine Test Program (UETP) were analyzed and compared to the pretest estimates.
The proposed procedure provides a mechanism for determining the expected accuracy of test results obtained from facilities which were not previously cross calibrated. Furthermore, the method can be used to assist in making cost-effective management decisions on the level of validation/cross calibration necessary when bringing a test facility on line.
This document is also intended to act as a guide for improving uncertainty analyses in a broad spectrum of related industries. Measurement uncertainty and measurement system approaches and practices for the UETP are presented in a systematic format. Readers can use these uncertainty approaches and practices for comparison to their own measurement systems.
The approach chosen was to analyze three of the UETP test conditions at eight test facilities along with the individual measurement system approaches and practices. The test program provided a wide range of performance measurements and corresponding pretest uncertainty estimates encompassing a variety of test and measurement approaches and practices. Included in the analysis are the basic gas turbine performance measurements of temperature, pressure, airflow, fuel flow, area, speed, thrust, and typical performance parameter functions and associated uncertainty estimates.
Recommended Content
Data Sets - Support Documents
| Title | Description | Download |
|---|---|---|
| TABLE 1 | The Measurement Uncertainty Process | |
| TABLE 2 | Curve-Slope Effects on UETP Performance Parameters | |
| Unnamed Dataset 3 | ||
| TABLE 3 | Station 5 and 7 Instrumentation Summary | |
| Unnamed Dataset 5 | ||
| TABLE 4 | Engine and Facility Test Combination Summary | |
| TABLE 5 | Population Standard Deviation Factors(1/d ) | |
| TABLE 6 | Range of Pre and Posttest Uncertainties for Performance Parameters at Three Test Conditions (P5Q2=2.1) | |
| TABLE 7 | 2S Presented as a Percentage of Ῡ | |
| TABLE A2 | ||
| TABLE A3 | ||
| TABLE A4 | ||
| TABLE A5 | ||
| TABLE B1 | Pressure Measurement Process Components and Practices | |
| TABLE B2 | Temperature Measurement Process Components and Practices | |
| TABLE B3 | Speed Measurement Process Components and Practices | |
| TABLE B4 | Force Measurement Process Components and Practices | |
| TABLE B5 | Fuel Flow Measurement Process Components and Practices | |
| TABLE C1 | The Range of Facility Error Components for Elemental Measurements for Three Test Conditions | |
| TABLE C2 | The Range of Facility Uncertainty Components for Performance Parameters for Three Test Conditions | |
| TABLE C3 | The Range of Facility Uncertainties for Performance Parameters for Three Test Conditions | |
| TABLE E1 | Systematic Uncertainty Data for Test Condition 3 | |
| TABLE E2 | Systematic Uncertainty Data For Test Condition 9 | |
| TABLE E3 | Systematic Uncertainty Data For Test Condition 11 |
Issuing Committee
E-33 In Flight Propulsion Measurement Committee
Reviews industry experience and state-of-the-art on in-flight thrust, meassurement and its uncertainty, including ASME, ISO, MIDAP, USAF, JANNAF, and NIST methods - including sources of error. Determines whether there is a basis to support development of a procedure for determing uncertainty, and review methods of measuring in-flight thrust. from possible drafting of information documents. Produces several SAE Aerospace Information Reports on Determination of In-Flight Thrust and Measurement Uncertainty of In-Flight Thrust Determination.
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