This standard specifies the special terms for the aerodynamic characteristics of two-wheeled motorcycles and mopeds, including the aerodynamic characteristics, aerodynamic forces, aerodynamic moments and coefficients. This standard is applicable to two-wheeled motorcycles and mopeds, and can also be used as a reference for other motorcycles. GB/T 15028.4-1994 Motorcycle handling stability terminology aerodynamic characteristics GB/T15028.4-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Terminology of controllability and stability-Aerodynamic characteristics
Motorcycles-Terminology of controllability and stability-Aerodynamic characteristicsSubject content and scope of application
GB/T 1 5028.4-94
This standard specifies the special terms for variables, air forces, air moments and coefficients of aerodynamic characteristics of two-wheeled motorcycles and mopeds.
This standard applies to two-wheeled motorcycles and mopeds, and can also be used as a reference for other motorcycles. 2 Referenced standards
GB/T15028.1Terminology of motorcycle controllability and stability-Coordinate system and motion 3 Winds
3.1 Steady windsteady wind
Wind whose wind speed and wind direction do not change with time. 3.2 Unsteady windunsteady wind
Wind when the maximum wind speed and minimum wind speed difference within 10s is up to 10m/s. 3.3 Gust of wind
The wind measured when the difference between the maximum and minimum wind speeds within 10 seconds is 10 m/s. 4.Aerodynamic variables4.1 Ambient wind velocityambient wind velocityThe horizontal component of the wind speed relative to the road surface plane (see Figure 1). 4.2 Ambient wind angleambientwind angleThe angle between the X-axis of the ground fixed coordinate system (see GB/T15028.1) and the projection of the wind speed on the road surface plane (see Figure 1). Relative wind velocityresultant wind velocity4.3
The vector difference between the vehicle speed and the wind speed at the center of mass of the vehicle-driver system (see Figure 1). Aerodynamic sideslip angleaerodynamic sideslip angle4.4
The angle between the relative wind speed and the projection of the axis of the vehicle coordinate system on the road surface plane (see Figure 1). aerodynamic angle of attackaerodynamic angle of attack4.5
The angle between the projection of the relative wind speed on the plane perpendicular to the axis and the axis of the vehicle coordinate system (see Figure 2). 4.6 center of wind pressurecenter of wind pressureThe intersection of the longitudinal plane of the vehicle and the line of action of the relative wind speed. 4.7frontal projected areaApproved by the State Administration of Technical Supervision on April 4, 1994, and implemented on November 1, 1994
GB/T15028.4—94
The frontal projected area of ​​the vehicle-driver system on the -z plane. 4.8 standard atmospherestandard atmosphereEnvironment under the conditions of a standard atmospheric pressure (101.325 kPa) and a temperature of 288 K, with an air density of 1.225 kg/m and a kinematic viscosity coefficient of 1.466×10~5 m2/s. 5 aerodynamic forces moments and coefficients5.1 components of aerodynamic forces and momentscomponents of aerodynamic forces and momentsThe components of forces and moments of an airflow acting on the vehicle-driver system in the vehicle coordinate system. 5.2 aerodynamic pressuredynamic pressurehalf the product of air density and the square of relative wind speedpua
where:9
aerodynamic pressure, Pa;
- air density, kg/m;
- relative wind speed, m/s.
5.3 drag
the component of an airflow acting on the vehicle-driver system on the axis. 5.4 drag coefficientdragcoefficientThe product of the orthographic projection area and the aerodynamic pressure divided by the air drag. Cx
Where: C
Air drag coefficient;
Air drag, N;
Aerodynamic pressure, Pa;
Orthogonal projection area, m2.
5.5Air lateral force
lateral force
The component of an airflow acting on the vehicle-driver system on the axis. Air lateral force coefficientlateral forcecoefficient5.6
The product of the orthogonal projection area and the aerodynamic pressure divided by the air lateral force. Cy
Where: C,—
Air lateral force coefficient;
Air lateral force, N,
A-Orthogonal projection area, m.
5.7Air liftlift
The component of an airflow acting on the vehicle-driver system on the axis. 5.8 Lift coefficient The product of the orthographic projection area and the aerodynamic pressure divided by the air lift. C
Lift coefficient;
Where: C,-
Air lift, N,
Aerodynamic pressure, Pa;
-orthographic projection area, m.
GB/T 15028.4—94
5.9Aerodynamic roll momentThe moment of the aerodynamic force acting on the vehicle-driver system on the axis. 5.10Aerodynamic roll moment coefficientThe product of the aerodynamic pressure and the orthographic projection area and the reference length (axis moment) divided by the aerodynamic roll moment. CMx
Where: Cm
aerodynamic pitch moment coefficient;
aerodynamic pitch moment, N·m,
aerodynamic pressure, Pa,
-orthographic projection area, m2,
reference length (axial moment), m.
aerodynamic pitch momentaerodynamic pitch moment5.11
The moment of the aerodynamic force acting on the vehicle-driver system. M
aerodynamic pitch moment coefficientaerodynamic pitch moment coefficient5.12
The product of aerodynamic pressure and orthographic projection area and reference length (axial moment) divided by the aerodynamic pitch moment. CMy'
Where: CMy-
air pitch moment coefficient;
air pitch moment, N·m;
aerodynamic pressure, Pa;
orthographic projection area, m\;
reference length (axial moment), m.
aerodynamic yaw momentaerodynamicyawmomentcoefficient5.13
The moment of the air force on the vehicle-driver system about the axis. 5.14aerodynamic yaw moment coefficientaerodynamic yaw moment coefficientThe product of aerodynamic pressure and orthographic projection area and reference length (axial moment) divided by the aerodynamic yaw moment. CMe
In the formula: CMr-
air yaw moment coefficient;
M'—air yaw moment, N·m,
q-air dynamic pressure, Pa
-orthographic projection area, m\;
reference length (axial moment), m.
GB/T 15028.4-94
Aerodynamic slip angle
Relative wind speed projection
Environmental wind speed angle
Environmental wind speed
Vehicle speed
'-axis projection
Axis projection
Aerodynamic angle of attack
Relative wind speed projection
Standard environment
Unstable wind
Wind pressure center
Environmental wind speed
Environmental wind speed angle
Air roll moment
Air roll moment coefficient
Air side force
Air side force coefficient
Aerodynamic variablesbzxz.net
Aerodynamic slip angle
Aerodynamic angle of attack
aerodynamic angle of attack
GB/T 15028.4—94
Appendix A
Chinese index (sorted by Chinese pinyin)
(Supplement)
Air dynamic pressure
Air yaw moment
Air yaw moment coefficient.
Aerodynamic forces, moments and coefficients
Aerodynamic forces and moments
Aero lift
Aero lift coefficient
Aero pitch moment.
Aero pitch moment coefficient…·
Aero drag
Aero drag coefficient
Steady wind
Relative wind speed
Orthographic projection area
Appendix B
English index
(Supplement)
aerodynamic forces moments and coefficientsaerodynamic pitch moment ..
aerodynamic pitch moment coefficientaerodynamic sidselip angle
aerodynamic variables
aerodynamic yaw moment
aerodynamic yaw moment coeffcientambient wind angle
ambient wind velocity
centre of wind pressure
GB/T 15028.4—94
compoments of aerodynamic forces and momentsD
drag coefficient
dynamic pressrue
frontal projected area
gust of wind
lateral force
lateral force coefficient
lift coefficient
resultant wind velocity
standard atmosphere
steady wind
unsteady wind
....3.3
Additional remarks:
GB/T15028.4—94
This standard was proposed by China National Automotive Industry Corporation. This standard is under the jurisdiction of the National Technical Committee for Automotive Standardization. This standard was drafted by the Ordnance Standardization Research Institute of the Ministry of Machinery and Electronics Industry. The main drafters of this standard are Han Huirong and Gao Yudong.
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