1、_ 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 suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews 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 2013 SAE International All rights reserved. No part of this p
3、ublication 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 DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.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/J2971_201304 SURFACE VEHICLE RECOMMENDED PRACTICE J2971 APR2013 Issued 2013-04 Tr
5、uck and Bus Aerodynamic Device and Concept Terminology RATIONALE The existing SAE J1594, Vehicle Aerodynamics Terminology recommended practice does not address the terminology describing the set of vehicle aerodynamic devices used on Trucks and Buses. To address this limitation the Truck and Bus Aer
6、odynamic and Fuel Economy Committee sponsored a Task Force to develop a Truck and Bus aerodynamic device terminology document. FOREWORD The extensive growth of state and federal regulations governing truck and trailer aerodynamic performance and the expansion of commercialization of aerodynamic devi
7、ces provides the opportunity for SAE to facilitate industry and government through standardization of truck and trailer aerodynamic terminology. This standard recognizes that the descriptions of truck and trailer aerodynamic devices and functions are unique from automotive ones detailed in J1594 Veh
8、icle Aerodynamics Terminology. Government, industry and academias uncontrolled attempts at adapting the historical automotive and aircraft based aerodynamic terminology to describe truck and trailer applications have resulted in a variety of inconsistent commercial and legal descriptions for the sam
9、e features or functions. Trademark, patent and copyright of terminology have also contributed to an expansion of inconsistent descriptors for components. The SAE Truck and Bus Aerodynamic and Fuel Economy Committee sponsored the SAE Truck and Bus J2971 Task Force to develop a recommended practice re
10、lated to Truck and Bus Aerodynamic Terminology. This document will support the use of J1321, J1526, J1252 as well as future truck and bus aerodynamic documents. SAE J2971 Revised APR2013 Page 2 of 29 TABLE OF CONTENTS 1. SCOPE 3 1.1 Purpose . 3 1.2 Document Use 3 2. REFERENCES 3 2.1 Applicable Docum
11、ents 3 2.2 Related Publication . 3 3. DEFINITIONS . 5 4. AERODYNAMIC DEVICES AND CONCEPTS . 7 4.1 Bus/Truck/Tractor Mounted Devices . 7 4.2 Freight Box/Trailer/Bus Mounted Devices . 12 4.3 Tire and Wheel Devices 18 4.4 General Devices 19 4.5 General Design Concepts . 23 5. NOTES 25 5.1 Marginal indi
12、cia . 25 APPENDIX A TERMINOLOGY FOR AERODYNAMIC DEVICES AND CONCEPTS FOR TRUCKS, TRAILERS AND BUSES . 26 FIGURE 1 SKETCH OF VEHICLE COORDINATE SYSTEM 9 FIGURE 2 TRUCK CAB AERODYNAMIC DEVICES . 9 FIGURE 3 TRUCK CAB ROOF MOUNTED AERODYNAMIC DEVICES 10 FIGURE 4 TRUCK CAB AERODYNAMIC DEVICES. 11 FIGURE
13、5 TRUCK CAB UNDERCARRIAGE AERODYNAMIC DEVICES. . 11 FIGURE 6 TRUCK CAB FRONT SIDE EDGE AERODYNAMIC DEVICES . 12 FIGURE 7 TRAILER BASE AERODYNAMIC DEVICES 14 FIGURE 8 TRAILER BASE AERODYNAMIC DEVICE 14 FIGURE 9 TRAILER BASE AERODYNAMIC DEVICES 15 FIGURE 10 TRAILER BASE AERODYNAMIC DEVICES 15 FIGURE 1
14、1 TRAILER BASE AERODYNAMIC DEVICES 16 FIGURE 12 TRAILER BASE AERODYNAMIC DEVICES 16 FIGURE 13 TRAILER AERODYNAMIC DEVICES . 17 FIGURE 14 TRAILER FRONT AERODYNAMIC DEVICES . 17 FIGURE 15 TRAILER FRONT AERODYNAMIC DEVICES . 17 FIGURE 16 TRAILER FRONT AERODYNAMIC DEVICES . 18 FIGURE 17 TRAILER UNDERCAR
15、RIAGE AERODYNAMIC DEVICES. . 18 FIGURE 18 TIRE AND WHEEL AERODYNAMIC DEVICES. 19 FIGURE 19 TIRE AND WHEEL AERODYNAMIC DEVICES. 19 FIGURE 20 BASE MASS INJECTION AERODYNAMIC DEVICE. 20 FIGURE 21 FLOW FENCE AERODYNAMIC DEVICE 21 FIGURE 22 FLOW STALL AERODYNAMIC DEVICE 21 FIGURE 23 DIFFUSER AERODYNAMIC
16、DEVICES 22 FIGURE 24 VORTEX GENERATOR AERODYNAMIC DEVICE . 22 FIGURE 25 VORTEX STRAKE AERODYNAMIC DEVICE 23 TABLE A1 TERMINOLOGY FOR AERODYNAMIC DEVICES AND CONCEPTS FOR TRUCKS, TRAILERS AND BUSES 26 SAE J2971 Revised APR2013 Page 3 of 29 1. SCOPE This SAE J2971 Recommended Practice Truck and Bus Ae
17、rodynamic Device Terminology document describes a standard naming convention of aerodynamic devices and technologies used to control aerodynamic forces on truck and buses weighing more than 10,000 pounds (including trailers). 1.1 Purpose This recommended practice provides a detailed list and definit
18、ion of truck and bus aerodynamic device terminology that may provide a common nomenclature for use in publishing data, reports and SAE recommended practices. 1.2 Document Use This document is structured to service both the novice and the expert user. 2. REFERENCES 2.1 Applicable Documents The follow
19、ing publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA a
20、nd Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J1252 SAE Wind Tunnel Test Procedure for Trucks and Buses SAE J2084 Aerodynamic Testing of Road Vehicles Testing Methods and Procedures SAE J1526 Joint TMC/SAE Fuel Consumption In-Service Test Procedure Type III SAE J1594 Vehicle Aerodynamic
21、s Terminology SAE J670 Vehicle Dynamics Terminology 2.1.2 Other Publications Aerodynamics of Road Vehicles, edited by W.H. Hucho, SAE 1998 2.2 Related Publication The following publications are provided for information purposes only and are not a required part of this document. 2.2.1 SAE Publication
22、s 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. SAE J2711 Recommended Practice for Measuring Fuel Economy and Emissions of Hybrid-Electric and Conventional Heavy-Duty Vehicles
23、 SAE J2881 Measurement of Aerodynamic Performance for Mass-Produced Cars and Light-Duty Trucks SAE J1263 Road Load Measurement and Dynamometer Simulation Using Coastdown Techniques SAE J2971 Revised APR2013 Page 4 of 29 SAE J2263 Road Load Measurement Using Onboard Anemometry and Coastdown Technique
24、s SAE J1264 Joint RCCC/SAE Fuel Consumption Test Procedure (Short Term In-Service Vehicle) Type 1 SAE Paper No. 750704 Comparison of Effectiveness of Commercially Available Devices for the Reduction of Aerodynamic Drag on Tractor Trailers, 1975. SAE Paper No. 840298 The Effect of Ambient Wind on a R
25、oad Vehicles Aerodynamic Work Requirement and Fuel Consumption, 1984. SAE TSB003 Rules for SAE use of SI (Metric) Units 2.2.2 Other Publications Available from the Technology and Maintenance Council, American Trucking Associations, 950 N. Glebe Road, Suite 210, Arlington, VA 22203-4181, Tel: 703-838
26、-1700, . TMC Report, “Report of Frederick, Maryland, Truck and Bus Fuel Economy Demonstration, Conducted October 22-November 1, 1979, by the Joint TMC/SAE Task Force for In-Service Test Procedures of The American Trucking Industry,“ November 1980. TMC RP 1109, Type IV Fuel Economy Test Procedure TMC
27、 RP 1102, TMC/SAE In-Service Fuel Consumption Test Procedure - Type II TMC RP 1103, TMC/SAE Fuel Consumption In-Service Test Procedure Recommended Practice - Type III TMC RP 1110 Aerodynamic Devices: Inspection and Maintenance Procedures TMC RP 1111 Relationships Between Truck Components and Fuel Ec
28、onomy TMC RP 1115 Guidelines for Qualifying Products Claiming a Fuel Economy Benefit 2.2.3 U.S. Government Publications CODE OF FEDERAL REGULATIONS (CFR) Available from the United States Government Printing Office, 732 North Capitol Street, NW, Washington, DC 20401, Tel: 202-512-0000, www.gpoaccess.
29、gov. EPA 40 CFR 1036.801 Definitions - Subpart I - Definitions and Other Reference Information - PART 1036 - Control of Emissions from New and In-Use Heavy-Duty Engines EPA 40 CFR 1037.801 Definitions - Subpart I - Definitions and Other Reference Information - Part 1037 - Control of Emissions from H
30、eavy-Duty Motor Vehicles EPA 40 CFR 1066.701 Definitions - Part 1066 Vehicle Testing Procedures EPA 40 1065.1001 Definitions - .Part 1065 - Engine Testing Procedures EPA 40 CFR 86.0122 Definitions. Part 86 - Control of Emissions from New and In-Use Highway Vehicles and Engines NHTSA 49 CFR 535.4 Def
31、initions - Medium- and Heavy-Duty Vehicle Fuel Efficiency Program NHTSA 49 CFR 523.2 Definitions - Vehicle Classification NHTSA 49 CFR 571.3 Definitions - Part 571 - Federal Motor Vehicle Safety Standards SAE J2971 Revised APR2013 Page 5 of 29 EPA Interim Requirements to Determine Eligibility of Sma
32、rtWay Tractors- (http:/www.epa.gov/smartway/documents/technology/get-designated/420-F-09-045.pdf) California EPA Title 17. Public Health, Division 3. Air Resources, Chapter 1. Air Resources Board Subchapter 10. Climate Change, Article 4. Regulations to Achieve Greenhouse Gas Emission Reductions, Sub
33、 article 1. Heavy-Duty Vehicle Greenhouse Gas Emission Reduction Regulation (Refs), 95302. Definitions. 3. DEFINITIONS 3.1 AERODYNAMICS A branch of dynamics that deals with the motion of air and other gaseous fluids and with the forces acting on bodies in motion relative to such fluids 3.2 AERODYNAM
34、IC DEVICE A structure or system added to the exterior of the vehicle for altering the aerodynamic forces acting on the vehicle. 3.3 ATTACHED FLOW Fluid flow along a surface and parallel to the surface tangent. 3.4 BASE The rearmost aft-facing surface of the cab, sleeper, tractor, trailer, truck or b
35、us. 3.5 BOUNDARY LAYER The layer of fluid in the immediate vicinity of a surface where the effects of viscosity are significant. 3.6 LAMINAR BUBBLE A separation of the laminar boundary layer that is constrained by the downstream reattachment of a turbulent boundary layer. 3.7 COANDA EFFECT The tende
36、ncy of a fluid jet to be attracted to a nearby surface. 3.8 CROSS FLOW Wind velocity that is at an angle to the vehicle longitudinal centerline. 3.9 DEVICE, AERODYNAMIC A contrivance, invention, technique or means serving a particular purpose, used to modify the aerodynamics of the vehicle. 3.10 DRA
37、G FORCE The aerodynamic force that opposes the forward motion of the vehicle. 3.11 FAIRING An aerodynamically shaped structure that covers a poorly shaped structure that is typically used to reduce aerodynamic drag. SAE J2971 Revised APR2013 Page 6 of 29 3.12 FLOW ANGLE The angle between the bodys r
38、eference line and the oncoming flow. 3.13 FLOW CONTROL A system that modifies the mass, momentum, or energy of the flow to modify the aerodynamics of the vehicle. 3.14 FLOW SEPARATION A condition in which fluid flow becomes detached from the surface of the object and takes the forms of eddies and vo
39、rtices. 3.15 GAP, TRACTOR TO TRAILER Longitudinal distance between the vertical flat surface of the back of the cab / sleeper to the vertical flat surface on the front of the trailer. 3.16 LIFT FORCE The aerodynamic force that acts perpendicular in a vertical direction to the forward motion of the v
40、ehicle. 3.17 LAMINAR FLOW Fluid flows in parallel layers, with no disruption between the layers of viscous fluid near a boundary. 3.18 REVERSE FLOW The portion of the boundary layer or free stream flow that reverses in flow direction. 3.19 REYNOLDS NUMBER A dimensionless number that gives a measure
41、of the ratio of inertial forces to viscous forces and consequently quantifies the relative importance of these two types of forces for given flow conditions. 3.20 SEMI-TRAILER Truck trailer supported at the rear by its own wheels and at the front by a fifth wheel mounted to a tractor or dolly. 3.21
42、SEPARATION POINT A point where the boundary layer flow becomes detached from the surface. 3.22 SLOT (Aerodynamic Gap) Longitudinal distance between the aft most point of the cab external surface, including aerodynamic side fairings, and the forward most point of the cargo carrying portion of the veh
43、icle. 3.23 STAGNATION LINE A location on the surface where the fluid is brought to rest (zero velocity). SAE J2971 Revised APR2013 Page 7 of 29 3.24 TRACTOR A vehicle designed primarily to pull a semi-trailer by the use of the fifth wheel that is mounted over its drive axle(s). May be called a truck
44、/highway tractor to differentiate it from a farm tractor. 3.25 TRAILER A freight carrying unpowered unit pulled by a powered unit. 3.26 TRUCK A vehicle which carries cargo in a body (van, tank, etc.) which is mounted to a chassis, possibly in addition to a trailer which is towed by the powered vehic
45、le. 3.27 TRUCK-TRAILER A truck-trailer combination consists of a truck that holds cargo in its body which is connected to its chassis, and which tows a trailer. 3.28 TURBULENT FLOW A flow regime characterized by chaotic and stochastic property changes. 3.29 VORTEX A spinning, often turbulent, flow o
46、f fluid. Any spiral motion with closed streamlines. 3.30 YAW ANGLE The effective wind angle experienced by the vehicle based upon vehicle ground velocity, wind velocity and wind angle, relative to the vehicle heading. Vehicle drag increases exponentially with increasing yaw angle. 4. AERODYNAMIC DEV
47、ICES AND CONCEPTS A description of the aerodynamic devices and concepts used within the truck and bus community is provided below and within Table A1 located in Appendix A. The following information makes use of the coordinate system shown in Figure 1. 4.1 Bus/Truck/Tractor Mounted Devices 4.1.1 Aer
48、odynamic Bumper Three-dimensional smoothly-contoured solid-surface bumper mounted at the front of the vehicle. See Figure 2. 4.1.2 Aerodynamic Mirror A mirror with a fairing covering the upstream forward-facing portion of the mirror. See Figure 2. 4.1.3 Aerodynamic Visor/Slat Three-dimensional smoot
49、hly-contoured solid-surface airfoil shaped structure attached to the leading edge of the vehicle cab roof. See Figure 4. SAE J2971 Revised APR2013 Page 8 of 29 4.1.4 Air Dam (Front Spoiler / Front Lip / Lip Spoiler / Valence) Vertically-orientated solid-surface structure that attaches below the front bumper. See Figure 2. 4.1.5 Cab Edge Radius Curved section joining the cab forward facing surface to t
