1、 AEROSPACE INFORMATION REPORT (R) Method of Evaluating Pneumatic Ground Power Units SAE Technical Standards Board Rules provide that: “This 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 s
2、uitability for any particular use, including any patent infringement arising therefrom, 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 invites your written comments and suggestions. C
3、opyright 2004 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrieval system 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 DOCUMEN
4、T ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA) Fax: 724-776-0790 Email: custsvcsae.org SAE WEB ADDRESS: http:/www.sae.org Issued 1992-02 Reaffirmed 2003-11 Revised 2004-07 Superseding AIR4545 AIR4545 REV.A 1. SCOPE: This SAE Aerospace Information Report (AIR) cove
5、rs, and is restricted to, the behavior of air under conditions of critical and subcritical flow at temperatures less than 500 F. 1.1 Purpose: This AIR is intended to provide basic information and theoretical background on a proper type of test equipment and calculation procedures for use in measurin
6、g air in critical and subcritical flow conditions, as are usually encountered in jet engine starting applications and to provide guidance in the construction of test apparatus. Additionally, a method for simplifying the calculations performed by technicians is presented. 2. APPLICABLE DOCUMENTS: 2.1
7、 This AIR should be supplemented by the following document: ASME MFC-3M-1989, Measurement of Fluid Flow in Pipes Using Orifice, Nozzle, and Venturi 2.2 Other Publications: Loomis, A.W., ed., Compressed Air and Gas Data, Third Edition, NJ:Ingersoll-Rand, 1980 Hotchkiss, R. M., Accessory Controls Refe
8、rring to Table 2, in the 14.35 column, we find that Factor Y at 35 inch H2O pressure = 2.247. Multiplying X*Y = 122.8919*2.247 =276 lb/min mass flow rate. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-
9、SAE AIR4545 Revision A - 9 - 6. CONSTRUCTION OF THE TEST APARATUS: 6.1 Overall Construction of Test Apparatus: The general layout of the test apparatus is shown in Figure 2 with details of the flow test duct shown in Figure 3 and Figure 4 below. FIGURE 2 - Test Apparatus Schematic Copyright SAE
10、International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR4545 Revision A - 10 - FIGURE 3 - Construction of Flow Test Duct Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproducti
11、on or networking permitted without license from IHS-,-,-SAE AIR4545 Revision A - 11 - FIGURE 4 - Detail of Duct Inlet Flange Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE AIR4545 Revision A - 1
12、2 - 6.2 Construction of Quarter Eliptical Nozzle: Construction details of the nozzle are shown in Figure 5 and Figure 6 below. FIGURE 5 - Nozzle Details Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-
13、SAE AIR4545 Revision A - 13 - FIGURE 6 - Elipse Machining Instructions 7. NOTES: 7.1 The change bar ( l ) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R)
14、symbol to the left of the document title indicates a complete revision of the document. PREPARED UNDER THE JURISDICTION OF SAE SUBCOMMITTEE AGE-2C, VEHICLE MAINTENANCE AND AIRCRAFT SERVICING, OF COMMITTEE AGE-2, AIR CARGO AND AIRCRAFT GROUND EQUIPMENT AND SYSTEMS Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
