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As a simulation of road driving, wind tunnel testing of full-size vehicles produces certain errors in the aerodynamic forces, aerodynamic moments, and surface pressures. The magnitude of these errors, in general, depends on the following: a Flow quality b Determination of the reference dynamic pressure c Wind tunnel floor boundary layer d Test section geometry and position of the car within that geometry e Shape of the vehicle f Blockage ratio: The ratio of the cross-sectional area of the vehicle to the cross-sectional area of the wind tunnel nozzle g Wheel rotation h Internal flow in the model The SAE Standards Committee, Open Throat Wind Tunnel Adjustments had as a goal to document the knowledge of the influence of model interference on wind tunnel test results for automotive open jet wind tunnels.

The scope of this SAE Information Report is confined to wind-tunnel testing, although it is recognized that many aspects of the aerodynamic characteristics of road vehicles can be investigated in other test facilities (such as water-tanks) or, especially, on the road. For example, coastdown testing is often used to determine aerodynamic drag (either in isolation or as part of the total resistance), and artificial gust generators are used to investigate the sensitivity of vehicles to cross-wind gusts. Also excluded from the present Report are climatic wind-tunnel tests of road vehicles, which are defined in more detail in Section 3. The Report covers the aerodynamic requirements of a wind-tunnel for automotive testing, together with the facility equipment needed and the requirements affecting the test vehicle or model.

The scope of this SAE Information Report is confined to wind-tunnel testing, although it is recognized that many aspects of the aerodynamic characteristics of road vehicles can be investigated in other test facilities (such as water-tanks) or, especially, on the road. For example, coastdown testing is often used to determine aerodynamic drag (either in isolation or as part of the total resistance), and artificial gust generators are used to investigate the sensitivity of vehicles to cross-wind gusts. Also excluded from the present Report are climatic wind-tunnel tests of road vehicles, which are defined in more detail in Section 3. The Report covers the aerodynamic requirements of a wind-tunnel for automotive testing, together with the facility equipment needed and the requirements affecting the test vehicle or model.

As a simulation of road driving, wind tunnel testing of full-size vehicles produces certain errors in the aerodynamic forces, aerodynamic moments, and surface pressures. The magnitude of these errors, in general, depends on the following: a.) Flow quality, b.) Determination of the reference dynamic pressure, c.) Wind tunnel floor boundary layer, d.) Test section geometry and position of the car within that geometry, e.) Shape of the vehicle, f.) Blockage ratio: The ratio of the cross-sectional area of the vehicle to the cross-sectional area of the wind tunnel nozzle, g.) Wheel rotation, and h.) Internal flow in the model. The SAE Standards Committee, Open Throat Wind Tunnel Adjustments, had as a goal to document the knowledge of the influence of model interference on wind tunnel test results for automotive open jet wind tunnels. This document contains the following information related to this subject: a.) Design data of open throat wind tunnels, b.)

This document outlines general requirements for the use of Computational Fluid Dynamics (CFD) methods for aerodynamic simulation of mass-produced cars and light-duty trucks. The document provides guidance for aerodynamic simulation with CFD methods to support current vehicle characterization, vehicle development, vehicle concept development and vehicle component development. The guidelines presented in the document include Navier-Stokes and Lattice-Boltzmann based solvers.

This recommended practice provides a procedure for measuring and documenting the aerodynamic performance in a full-scale wind tunnel of passenger vehicles, i.e., mass-produced cars and light-duty trucks intended primarily for individual consumers. Testing or numerical modeling of pre-production and/or reduced-scale models is outside the scope of this document. Aerodynamic development procedures, i.e., methods to improve or optimize aerodynamic performance, are also excluded. It is well-known that aerodynamic performance results depend significantly on vehicle content and loading, as well as the wind tunnel itself (type, scale, and simulation qualities of the wind tunnel). Publication of non-standard test results causes unnecessary additional development work and incorrect perception of a vehicle’s anticipated aerodynamic performance by government, academia, and the general public.

This Recommended Practice provides a procedure for measuring and documenting the aerodynamic performance in a full-scale wind tunnel of passenger vehicles, i.e., mass-produced cars and light-duty trucks intended primarily for individual consumers. Testing or numerical modeling of pre-production and/or reduced-scale models is outside the scope of this document. Aerodynamic development procedures, i.e., methods to improve or optimize aerodynamic performance, are also excluded. It is well-known that aerodynamic performance results depend significantly on vehicle content and loading, as well as the wind tunnel itself (type, scale, and simulation qualities of the wind tunnel). Publication of non-standard test results causes unnecessary additional development work and incorrect perception of a vehicle’s anticipated aerodynamic performance by government, academia, and the general public.

This terminology is intended to provide a common nomenclature for use in publishing road vehicle aerodynamics data and reports.

This terminology is intended to provide a common nomenclature for use in publishing road vehicle aerodynamics data and reports.

This terminology is intended to provide a common nomenclature for use in publishing road vehicle aerodynamics data and reports.